[Federal Register Volume 79, Number 69 (Thursday, April 10, 2014)]
[Rules and Regulations]
[Pages 19973-20071]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-07302]
[[Page 19973]]
Vol. 79
Thursday,
No. 69
April 10, 2014
Part II
Department of the Interior
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Fish and Wildlife Service
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50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Determination of
Threatened Status for the Lesser Prairie-Chicken; Final Rule
Federal Register / Vol. 79 , No. 69 / Thursday, April 10, 2014 /
Rules and Regulations
[[Page 19974]]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R2-ES-2012-0071; 4500030113]
RIN 1018-AY21
Endangered and Threatened Wildlife and Plants; Determination of
Threatened Status for the Lesser Prairie-Chicken
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: We, the U.S. Fish and Wildlife Service, determine threatened
species status for the lesser prairie-chicken (Tympanuchus
pallidicinctus), a grassland bird known from southeastern Colorado,
western Kansas, eastern New Mexico, western Oklahoma, and the Texas
Panhandle, under the Endangered Species Act of 1973, as amended (Act).
This final rule implements the Federal protections provided by the Act
for the lesser prairie-chicken. Critical habitat is prudent but not
determinable at this time. Elsewhere in this issue of the Federal
Register, we published a final special rule under section 4(d) of the
Act for the lesser prairie-chicken.
DATES: This rule is effective on May 12, 2014.
ADDRESSES: Document availability: You may obtain copies of this final
rule on the Internet at http://www.regulations.gov at Docket No. FWS-
R2-ES-2012-0071 or by mail from the Oklahoma Ecological Services Field
Office (see FOR FURTHER INFORMATION CONTACT below). Comments and
materials received, as well as supporting documentation used in
preparing this final rule, are available for public inspection, by
appointment, during normal business hours at: U.S. Fish and Wildlife
Service, Oklahoma Ecological Services Field Office, 9014 East 21st
Street, Tulsa, OK 74129; telephone 918-581-7458; facsimile 918-581-
7467.
FOR FURTHER INFORMATION CONTACT: Alisa Shull, Acting Field Supervisor,
Oklahoma Ecological Services Field Office, 9014 East 21st Street,
Tulsa, OK 74129; by telephone 918-581-7458 or by facsimile 918-581-
7467. Persons who use a telecommunications device for the deaf (TDD)
may call the Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Executive Summary
This document consists of: (1) A final rule to list the lesser
prairie-chicken as a threatened species; and (2) a finding that
critical habitat is prudent but not determinable at this time.
Why we need to publish a rule. Under the Endangered Species Act
(Act), a species may warrant protection through listing if it is an
endangered or threatened species throughout all or a significant
portion of its range. The Act sets forth procedures for adding species
to, removing species from or reclassifying species on the Federal Lists
of Endangered and Threatened Wildlife and Plants. In this final rule,
we explain why the lesser prairie-chicken warrants protection under the
Act. This rule lists the lesser prairie-chicken as a threatened species
throughout its range.
The Act provides the basis for our action. Under the Act, we can
determine that a species is an endangered or threatened species based
on any of five factors: (A) The present or threatened destruction,
modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. The primary factors supporting the
determination of threatened status for the lesser prairie-chicken are
the ongoing and probable future impacts of cumulative habitat loss and
fragmentation. These impacts are the result of: Conversion of
grasslands to agricultural uses; encroachment by invasive, woody
plants; wind energy development; petroleum production; and presence of
roads and manmade vertical structures including towers, utility lines,
fences, turbines, wells, and buildings.
We requested peer review of the methods used in making our final
determination. We obtained opinions from knowledgeable individuals
having scientific expertise in this species or related fields (such as
range and fire ecology, shrub management and grouse management) and
solicited review of the scientific information and methods that we used
in developing the proposal. We obtained opinions from two knowledgeable
individuals with scientific expertise to review our technical
assumptions, analysis, adherence to regulations, and whether we had
used the best available information. These peer reviewers generally
concurred with our methods and conclusions and provided additional
information, clarifications, and suggestions to improve this final
listing rule.
We sought public comment on the proposed listing rule and the
proposed special rule under section 4(d) of the Act. During the first
comment period, we received 879 comment letters directly addressing the
proposed listing and critical habitat designation. During the second
comment period, we received 56,344 comment letters addressing the
proposed listing rule, proposed special rule, and related rangewide
conservation plan. During the third comment period, we received 12
comments regarding the proposed listing. During the fourth comment
period, we received 74 comments, primarily related to the proposed
revised special rule.
Previous Federal Actions
In 1973, the Service's Office of Endangered Species published a
list of threatened wildlife of the United States in Resource
Publication 114, often referred to as the ``Red Book.'' While this
publication did not, by itself, provide any special protections, the
publication served, in part, to solicit additional information
regarding the status of the identified taxa. The lesser prairie-chicken
was one of 70 birds included in this publication (Service 1973, pp.
134-135), but little Federal regulatory action occurred on the lesser
prairie-chicken until 1995.
On October 6, 1995, we received a petition, dated October 5, 1995,
from the Biodiversity Legal Foundation, Boulder, Colorado, and Marie E.
Morrissey (petitioners). The petitioners requested that we list the
lesser prairie-chicken as threatened throughout its known historical
range in the United States. The petitioners defined the historical
range to encompass west-central Texas north through eastern New Mexico
and western Oklahoma to southeastern Colorado and western Kansas, and
they stated that there may have been small populations in northeastern
Colorado and northwestern Nebraska. The petitioners also requested that
critical habitat be designated as soon as the needs of the species are
sufficiently well known. However, from October 1995 through April 1996,
we were under a moratorium on listing actions as a result of Public Law
104-6, which, along with a series of continuing budget resolutions,
eliminated or severely reduced our listing budget through April 1996.
We were unable to act on the petition during that period. On July 8,
1997 (62 FR 36482), we announced our 90-day finding that the petition
presented substantial information
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indicating that the petitioned action may be warranted. In that notice,
we requested additional information on the status, trend, distribution,
and habitat requirements of the species for use in conducting a status
review. We requested that information be submitted to us by September
8, 1997. In response to a request by the Lesser Prairie-Chicken
Interstate Working Group dated September 3, 1997, we reopened the
comment period for an additional 30 days, beginning on November 3, 1997
(62 FR 59334). We subsequently published our 12-month finding for the
lesser prairie-chicken on June 9, 1998 (63 FR 31400), concluding that
the petitioned action was warranted but precluded by other higher
priority listing actions.
The 12-month finding initially identified the lesser prairie-
chicken as a candidate for listing with a listing priority number (LPN)
of 8. Our policy (48 FR 43098; September 21, 1983) requires the
assignment of an LPN to all candidate species. This listing priority
system was developed to ensure that we have a rational system for
allocating limited resources in a way that ensures those species in
greatest need of protection are the first to receive such protection.
The listing priority system considers magnitude of threat, immediacy of
threat, and taxonomic distinctiveness in assigning species numerical
listing priorities on a scale from 1 to 12. In general, a smaller LPN
reflects a greater need for protection than a larger LPN. The lesser
prairie-chicken was assigned an LPN of 8, indicating that the magnitude
of threats was moderate and the immediacy of the threats to the species
was high.
On January 8, 2001 (66 FR 1295), we published our resubmitted
petition findings for 25 animal species, including the lesser prairie-
chicken, having outstanding ``warranted-but-precluded'' petition
findings as well as notice of one candidate removal. The lesser
prairie-chicken remained a candidate with an LPN of 8 in our October
30, 2001 (66 FR 54808); June 13, 2002 (67 FR 40657); May 4, 2004 (69 FR
24876); May 11, 2005 (70 FR 24870); September 12, 2006 (71 FR 53756);
and December 6, 2007 (72 FR 69034) candidate notices of review. In our
December 10, 2008 (73 FR 75176), candidate notice of review, we changed
the LPN for the lesser prairie-chicken from an 8 to a 2. This change in
LPN reflected a change in the magnitude of the threats from moderate to
high primarily due to an anticipated increase in the development of
wind energy and associated placement of transmission lines throughout
the estimated occupied range of the lesser prairie-chicken. Our June 9,
1998, 12-month finding (63 FR 31400) did not recognize wind energy and
transmission line development as a threat because such development
within the known range was almost nonexistent at that time. Changes in
the magnitude of other threats, such as conversion of certain
Conservation Reserve Program (CRP) lands from native grass cover to
cropland or other less ecologically valuable habitat and observed
increases in oil and gas development, also were important
considerations in our decision to change the LPN. The immediacy of the
threats to the species did not change and continued to be high. Our
November 9, 2009 (74 FR 57804), November 10, 2010 (75 FR 69222), and
October 26, 2011 (76 FR 66370) candidate notices of review retained an
LPN of 2 for the lesser prairie-chicken.
Since making our 12-month finding, we have received several 60-day
notices of intent to sue from WildEarth Guardians (formerly Forest
Guardians) and several other parties for failure to make expeditious
progress toward listing of the lesser prairie-chicken. These notices
were dated August 13, 2001; July 23, 2003; November 23, 2004; and May
11, 2010. WildEarth Guardians subsequently filed suit on September 1,
2010, in the U.S. District Court for the District of Colorado. A
revised notice of intent to sue dated January 24, 2011, in response to
motions from New Mexico Oil and Gas Association, New Mexico Cattle
Growers Association, and Independent Petroleum Association of New
Mexico to intervene on behalf of the Secretary of the Interior, also
was received from WildEarth Guardians.
This complaint was subsequently consolidated in the U.S. District
Court for the District of Columbia along with several other cases filed
by the Center for Biological Diversity or WildEarth Guardians relating
to petition finding deadlines and expeditious progress toward listing.
A settlement agreement in In re Endangered Species Act Section 4
Deadline Litigation, No. 10-377 (EGS), MDL Docket No. 2165 (D.D.C. May
10, 2011) was reached with WildEarth Guardians in which we agreed to
submit a proposed listing rule for the lesser prairie-chicken to the
Federal Register for publication by September 30, 2012.
On September 27, 2012, the settlement agreement was modified to
require that the proposed listing rule be submitted to the Federal
Register on or before November 29, 2012. On December 11, 2012, we
published a proposed rule (77 FR 73828) to list the lesser prairie-
chicken as a threatened species under the Act (16 U.S.C. 1531 et seq.).
Publication of the proposed rule opened a 90-day comment period that
closed on March 11, 2013. We held a public meeting and hearing in
Woodward, Oklahoma, on February 5, 2013; in Garden City, Kansas, on
February 7, 2013; in Lubbock, Texas, on February 11, 2013; and in
Roswell, New Mexico, on February 12, 2013.
On May 6, 2013, we announced the publication of a proposed special
rule under the authority of section 4(d) of the Act. At this time, we
reopened the comment period on the proposed listing rule (77 FR 73828)
to provide an opportunity for the public to simultaneously provide
comments on the proposed listing rule, the proposed special rule, and a
draft rangewide conservation plan for the lesser prairie-chicken. This
comment period was open from May 6 to June 20, 2013.
On July 9, 2013, we announced a 6-month extension (78 FR 41022) of
the final listing determination based on our finding that there was
substantial disagreement regarding the sufficiency or accuracy of the
available data relevant to our determination regarding the proposed
listing rule. We again reopened the comment period to solicit
additional information. This comment period closed on August 8, 2013.
We reopened the comment period again on December 11, 2013 (78 FR
75306), to solicit comments on a revised proposed special rule and our
December 11, 2012, proposed listing rule. This comment period closed on
January 10, 2014. However, the endorsed version of the Western
Association of Fish and Wildlife Agencies' Lesser Prairie-Chicken
Range-wide Conservation Plan was not available on the Web sites, as
stated in the December 11, 2013, revised proposed special 4(d) rule (78
FR 75306), at that time. We subsequently reopened the comment period on
January 29, 2014 (79 FR 4652), to allow the public the opportunity to
have access to this rangewide plan and submit comments on the revised
proposed special rule and our December 11, 2012, proposed listing rule.
This comment period closed on February 12, 2014.
Summary of Comments and Recommendations
We requested written comments from the public on the proposed
listing of the lesser prairie-chicken during five comment periods:
December 11, 2012, to March 11, 2013; May 6 to June 20, 2013; July 9 to
August 8, 2013; December 11, 2013, to January 10, 2014; and January 29
to February 12, 2014. Additionally four public hearings were held in
February 2013; February 5th in
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Woodward, Oklahoma; February 7th in Garden City, Kansas; February 11th
in Lubbock, Texas; and February 12th in Roswell, New Mexico. We also
contacted appropriate Federal, Tribal, State, and local agencies;
scientific organizations; and other interested parties and invited them
to comment on the proposed rule, proposed special rule, draft rangewide
conservation plan, and final rangewide conservation plan during the
respective comment periods.
Over the course of the five comment periods, we received
approximately 57,350 comment submissions. Of these, approximately
56,800 were form letters. Additionally, during the February 2013 public
hearings, 85 individuals or organizations provided comments on the
proposed rule. All substantive information provided during these
comment periods, including the public hearings, has either been
incorporated directly into this final determination or is addressed
below. Comments from peer reviewers and State agencies are grouped
separately. In addition to the comments, some commenters submitted
additional reports and references for our consideration, which we
reviewed and incorporated into this final rule as appropriate.
Peer Reviewer Comments
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinions from nine knowledgeable
individuals with scientific expertise that included familiarity with
the species, the geographic region in which the species occur, and
conservation biology principles. We received responses from two of the
nine peer reviewers we contacted.
We reviewed all comments received from the two peer reviewers
regarding the analysis of threats to the lesser prairie-chicken and our
proposed threatened listing determination. The peer reviewers generally
concurred with our methods and conclusions, and provided additional
information, clarifications, and suggestions to improve this final
rule. Peer reviewer comments are addressed in the following summary and
incorporated into the final rule, as appropriate.
(1) Comment: Conservation efforts to date have not been adequate to
address known threats.
Our Response: While considerable effort has been expended over the
past several years to address some of the known threats throughout
portions or all of the species' estimated occupied range, threats to
the continued viability of the lesser prairie-chicken into the future
remain. Recent development of conservation plans has highlighted the
importance of not only habitat restoration and enhancement but also the
role of the States and other partners in reducing many of the known
threats to the lesser prairie-chicken. Consequently, we proposed a
special rule under section 4(d) of the Act that facilitates
conservation implementation and threat reduction through development or
implementation of certain types of conservation plans and efforts. Such
plans will help provide the ongoing, targeted implementation of
appropriate conservation actions that are an important aspect of
collaborative efforts to improve the status of the species. We discuss
the various conservation efforts occurring within the estimated
occupied range of the lesser prairie-chicken in more detail in the
Summary of Ongoing and Future Conservation Efforts, below.
(2) Comment: Grain crops may be used by lesser prairie-chickens
more extensively than indicated in the rule, particularly considering
that conversion of the prairies to crop production led to expansion, at
least temporarily, of lesser prairie-chicken populations.
Our Response: Grain crops are used by lesser prairie-chickens and
may have temporarily led to range expansion, but the best available
information does not detail how extensively grains are used by lesser
prairie-chickens. Considering food is likely rarely limiting for lesser
prairie-chickens, grains are likely used advantageously and are not
necessary for survival. However, lesser prairie-chickens may be more
dependent upon waste grain during drought or prolonged periods of
extreme winter weather. Lesser prairie-chickens tend to predominantly
rely on cultivated grains when production of natural foods, such as
acorns and grass and forb seeds, are deficient (Copelin 1963, p. 47).
Therefore, agricultural grain crops, particularly when irrigated and
with additional nutrient inputs, can be a more reliable, but temporary,
food source than native foods that fluctuate with environmental
conditions. However, there is a cost to the species associated with
using grain fields in terms of exposure to predation, energy
expenditure, and weather. Copelin (1963, entire) indicates that lesser
prairie-chickens will occasionally use grain crops, but it appears that
native foods are generally preferred. Additionally, as the extent of
agricultural lands increases within the landscape, native grass and
shrubland habitats that are used by lesser prairie-chickens for all
life-history stages, not limited to foraging, decline. Kukal (2010, pp.
22, 24) found that lesser prairie-chickens did not move long distances
to access grain fields and may spend the fall and winter exclusively in
grasslands even when grain fields, primarily wheat, are available.
While this likely indicates that wheat is not a preferred grain source,
or that grains are not readily available on winter wheat fields, the
best scientific information indicates that crop fields are less
important to lesser prairie-chicken survival than are native grasslands
in good condition because native grasslands are more likely to provide
necessary habitat for lekking, nesting, brood rearing, feeding for
young, and feeding for adults, among other things. Accordingly, this
rule characterizes waste grains and grain agriculture as important
during prolonged periods of adverse winter weather but unnecessary for
lesser prairie-chicken survival during most years and in most regions.
A more detailed discussion of lesser prairie-chicken use of grain crops
is provided in the ``Life-History Characteristics'' section, below.
(3) Comment: The Service should not list population segments of the
lesser prairie-chicken in Kansas, where those populations meet or
exceed population thresholds established by an objective and
independent team of species experts. Specifically, the Service could
designate a distinct population segment in Kansas and exclude it from
any listing action.
Our Response: The Act allows us to list only species, subspecies,
or distinct population segments of a species or subspecies, as section
3(16) of the Act defines species to include ``any subspecies of fish or
wildlife or plants, and any distinct population segment of any species
of vertebrate fish or wildlife which interbreeds when mature.'' The
Service and the National Marine Fisheries Service jointly published a
``Policy Regarding the Recognition of Distinct Vertebrate Population
Segments Under the Endangered Species Act'' (DPS Policy) in the Federal
Register on February 7, 1996 (61 FR 4722). Under the DPS Policy, three
factors are considered in a decision concerning whether to establish
and classify a possible DPS. The first two factors, (1) discreteness of
the population segment in relation to the remainder of the taxon and
(2) the significance of the population segment to the taxon to which it
belongs, bear on whether the population segment can be a possible DPS.
The third factor bears on answering the question of whether the
population segment, when treated as if it were a species, is endangered
or threatened. In order to establish a DPS, all three factors must be
met. Under the
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DPS Policy, a population may be considered discrete if (1) it is
markedly separated from other populations of the same taxon as a
consequence of physical, physiological, ecological, or behavioral
factors; or (2) it is delimited by international governmental
boundaries with differences in control of exploitation, management of
habitat, conservation status, or relevant regulatory mechanisms. The
best scientific and commercial information available does not indicate
that lesser prairie-chicken populations in Kansas are discrete from the
populations in the neighboring States of Colorado or Oklahoma because
there is no marked separation from other populations. Thus, we do not
have the discretion to exclude populations in Kansas from the listing
because they do not meet the definition of a listable (or delistable)
entity. Please refer to the Determination section of this final listing
rule for further discussion.
(4) Comment: A recovery team should be established and critical
habitat proposed as quickly as possible following the final listing
decision.
Our Response: Under section 4(f)(1) of the Act, we are required to
develop and implement plans for the conservation and survival of
endangered and threatened species, unless the Secretary of the Interior
finds that such a plan will not promote the conservation of the
species. We will move to accomplish these tasks as soon as feasible. We
have determined in this final rule that critical habitat is not
determinable at this time; however, we are required under section
4(b)(6)(C)(ii) of the Act to make our critical habitat determination
within one year from the publication date of this final rule.
(5) Comment: Speciation in members of the genus Tympanuchus may be
incomplete, and statements regarding taxonomy should be revised to more
fully disclose the current state of genetic and taxonomic information.
Electronic copies of several publications were provided to aid the
Service's review of this information.
Our Response: As stated in the final rule, we agree that there is
some uncertainty regarding the taxonomic status of the lesser prairie-
chicken and other related members of the genus. For example, Johnsgard
(1983, p. 316) initially considered the greater and lesser prairie-
chickens to be allopatric subspecies, meaning that they originated as
the same species but populations became isolated from each other to an
extent that prevented genetic interchange, causing speciation. However,
the American Ornithologists Union recognizes the lesser prairie-chicken
as a species, and we have concluded that the lesser prairie-chicken is
sufficiently distinct from other members of the genus to meet the Act's
definition of a species. The American Ornithologists Union considers
the lesser prairie-chicken to be distinct from the greater prairie-
chicken based on known differences in behavior, habitat affiliation,
and social aggregation (Ellsworth et al. 1994, p. 662). We have revised
the rule to include a more thorough discussion of prairie grouse
phylogeny (the evolutionary history of taxonomic groups).
(6) Comment: Under conditions of high production and large
population size, lesser prairie-chickens would be able to disperse up
to 48 kilometers (km) (30 miles (mi)) annually and be able to
recolonize areas fairly quickly. Similarly, if birds were at least
partially migratory in the past, recolonization could occur more
rapidly than indicated in the proposed rule.
Our Response: There is limited information available on the
dispersal capabilities of lesser prairie-chickens, but the best
scientific information available to us supports that lesser prairie-
chickens exhibit limited dispersal tendencies and do not disperse over
long distances. In Texas, Haukos (1988, p. 46) recorded daily movements
of 0.1 km (0.06 mi) to greater than 6 km (3.7 mi) by female lesser
prairie-chickens prior to onset of incubation. Taylor and Guthery
(1980b, p. 522) documented a single male moving 12.8 km (8 mi) in 4
days, which they considered to be a dispersal movement. This
information does not support the conclusion that individuals have or
could disperse up to 48 km (30 mi). Due to their heavy wing loading,
they are relatively poor fliers. For these reasons, we do not consider
lesser prairie-chickens to be good dispersers.
The existence of large-scale migration movements of lesser prairie-
chickens is not known, but it is possible that the species was at least
partially migratory in the past. Both Bent (1932, pp. 284-285) and
Sharpe (1968, pp. 41-42) thought that the species, at least
historically, might have been migratory with separate breeding and
wintering ranges. Taylor and Guthery (1980a, p. 10) also thought the
species was migratory prior to widespread settlement of the High
Plains, but migratory movements have not recently been documented. The
lesser prairie-chicken is now thought to be nonmigratory.
The species' limited dispersal and migration capabilities are
unlikely to significantly contribute to recolonization under current
conditions, particularly considering the fragmented nature of the
occupied range.
Recolonization of former lesser prairie-chicken habitat is most
likely to occur in habitats that are located in close proximity to
existing populations, particularly considering the extent of habitat
fragmentation that exists within the occupied range and reduced
population size. Due to the lesser prairie chicken's relatively limited
movements, their site fidelity, and difficulty in translocating
individuals, management efforts are best concentrated on improving
habitat conditions in areas adjacent to existing populations and
allowing individuals to recolonize those habitats naturally. Under
appropriate conditions, populations can recolonize these adjacent areas
relatively quickly, provided surplus numbers exist to support
dispersal. As evidenced by the reoccupation of former range in Kansas,
where large blocks of high-quality habitat were created through the
CRP, recolonization is possible but is most likely to occur over the
long term (8 to 12 years) in habitats within close proximity to
existing populations. As conservation efforts for this species continue
and recovery planning would be initiated post-listing, conservation
actions such as habitat improvement may include areas that are most
likely to support population expansion.
(7) Comment: The extent of the historical range provides little
information with regard to density of lesser prairie-chickens, and some
portions of the historical range may not have been suitable for lesser
prairie-chickens even 100 years ago. The extent of the historical range
is a somewhat arbitrary benchmark and should not be used when making
comparisons with respect to currently occupied range.
Our Response: We recognize that not all of the Service's defined
historical range was optimal habitat, and very little information
regarding historical densities of lesser prairie-chickens exists.
However, one of the factors we must consider in our listing
determination relates to the present or threatened destruction,
modification, or curtailment of a species' habitat or range.
Accordingly, comparing the likely extent of historical range with
currently occupied range provides insight into whether the range of a
species has been lost or reduced over time. We agree that the extent of
the historical range is an estimate and use this term, and the term
``approximate,'' in referring to the historical range. We also
recognize that the extent of historical range may have fluctuated over
time, based on habitat conditions
[[Page 19978]]
evident at any one period, and the estimated historical range may
represent the maximum range that was occupied during historical times.
The information we present in this rule serves to reflect the estimated
extent of the historical range based on the best available information
and provides some context with which we can discuss the estimated
occupied range. While our calculations of the loss of historical range
are an estimate and not an exact value, they demonstrate that the range
of the lesser prairie-chicken likely has contracted substantially since
pre-European settlement.
(8) Comment: The rule fails to consider that the occupied range of
the lesser prairie-chicken has expanded to include portions of
northwest Kansas and may be larger than in the recent past.
Our Response: Our proposed rule clearly states that the lesser
prairie-chicken occupies areas in Ellis, Graham, Sheridan, and Trego
Counties in Kansas that extend beyond the previously delineated
historical range. Our calculations of the estimated occupied range and
the estimated occupied range plus a 16-km (10-mi) buffer also recognize
the existence of populations in those counties. However, the best
scientific and commercial information available indicates the range in
northwestern Kansas does not represent a range expansion for lesser
prairie-chicken; instead, we consider this to be a reoccupation of
former range.
(9) Comment: The extent of agricultural land within the range of
the lesser prairie-chicken may decline, particularly considering the
High Plains (Ogallala) Aquifer may be economically depleted in 20
years.
Our Response: The best scientific and commercial information
available does not indicate that the extent of agricultural land will
decline significantly in the near future, even if the level of the High
Plains Aquifer declines. Terrell et al. (2002, p. 35), Sophocleous
(2005, p. 361), and Drummond (2007, p. 142) all concluded that, while
declining water levels in the High Plains Aquifer may cause some areas
of cropland to revert to grassland, most of the irrigated land likely
will transition to dryland agriculture, despite the increased use of
more efficient methods of irrigation in response to declining water
supplies for irrigation. This information has been incorporated into
this final rule.
(10) Comment: Work by Hovick et al. (unpublished manuscript in
review) on anthropogenic structures and grouse that has been submitted
for publication should be considered. This work shows a consistent and
negative relationship between grouse and certain manmade structures,
including oil and gas infrastructure, power lines, and wind turbines.
Our Response: We agree with this comment and have incorporated the
findings of this study into this rule. This study examined the effect
of 23 different types of anthropogenic structures on grouse
displacement behavior and found that all structure types examined
resulted in displacement, but oil structures and roads had the greatest
impact on grouse avoidance behavior (Hovick et al. unpublished
manuscript under review, p. 11). They also examined the effect of 17 of
these structures on survival and found all of the structures examined
also decreased survival in grouse, with lek attendance declining at a
greater magnitude than other survival parameters measured (Hovick et
al. unpublished manuscript under review, p. 12). This information
supports our conclusion that the presence of vertical structures
contributes to functional fragmentation of lesser prairie-chicken
habitat.
(11) Comment: Statements regarding the impact of recreational
viewing, particularly with respect to the size of the lek, are
speculative and more information should be provided.
Our Response: There is little direct evidence regarding impacts of
recreational viewing at lesser prairie-chicken leks. Consequently, we
cannot provide more definitive information within this section than the
discussion in the proposed and final rules. Based on the best
scientific and commercial information available at this time, we do not
consider recreational viewing to be a significant impact to the species
as a whole. Please refer to the Hunting and Other Forms of
Recreational, Educational, or Scientific Use section, below, for our
discussion of potential impacts from recreational viewing.
(12) Comment: In the section on hybridization, the Service
incorrectly describes the lesser prairie-chicken populations in Kansas
that occur north of the Arkansas River as low density.
Our Response: We have revised that discussion to more clearly
reflect observed densities in the area of hybridization.
(13) Comment: The section on hybridization should be expanded and
clarified with respect to the fertility of hybrids. Populations within
the zone of overlap are not low density or ephemeral, and the zone of
overlap is more extensive than indicated by Bain and Farley (2000). The
hybridization issue, combined with information on speciation and
possibility of introgression, should be a high priority for research.
Our Response: We have expanded the section on hybridization to
include discussion related to fertility of first and second generation
hybrids. We have concerns with respect to the implications of
hybridization, but the best available information at this time does not
indicate that hybridization is a threat at current levels.
Comments From States
Section 4(i) of the Act states, ``the Secretary shall submit to the
State agency a written justification for [her] failure to adopt
regulations consistent with the agency's comments or petition.''
Comments received from the States of Colorado, Kansas, New Mexico,
Oklahoma, and Texas regarding the proposal to list the lesser prairie-
chicken as a threatened species are addressed below.
(14) Comment: Evidence shows that the lesser prairie-chicken
population is not only surviving, but has stabilized or increased,
despite other conditions, including drought in much of the region. This
conclusion is supported by Hagen 2012. Lesser prairie-chicken
populations can experience large fluctuations in numbers, but they have
remained within normal limits given annual precipitation over the past
12 years with no significant decrease; further, they have demonstrated
the ability to recover from similar drought episodes in the past.
Our Response: In June 2012, we were provided with the referenced
interim assessment of lesser prairie-chicken population trends since
1997 (Hagen 2012, entire). While the results of this analysis suggest
that lesser prairie-chicken population trends have increased since
1997, we are reluctant to place considerable weight on the interim
assessment for a number of reasons as discussed in the rule. The
``Rangewide Population Estimates'' section of this final listing rule
includes a full discussion of these reasons, in addition to a full
discussion of population estimates for the species. In summary, Hagen's
preliminary analysis evaluates lesser prairie-chicken population trends
from 1997 to 2012, whereas the Service's analysis of population
estimates as presented in the final rule dates back as far as records
are available.
Although lesser prairie-chicken populations can fluctuate
considerably from year to year in response to variable weather and
habitat conditions, generally the overall population size has continued
to decline from the estimates of population size available in the early
[[Page 19979]]
1900s (Robb and Schroeder 2005, p. 13). The ability of any species to
recover from an event, such as drought, is fully dependent upon the
density of individuals, the environmental conditions, the time that
those environmental conditions persist, and, most importantly, the
habitat quality and quantity available (including connectivity of that
habitat). An examination of anecdotal information on historical numbers
of lesser prairie-chickens indicates that numbers likely have declined
from possibly millions of birds to current estimates of thousands of
birds. Further, examination of the trends in the five lesser prairie-
chicken States for most indicator variables, such as males per lek and
lek density, over the last 3 years are indicative of declining
populations. The total estimated abundance of lesser prairie-chickens
in 2012 was 34,440 individuals (90 percent upper and lower confidence
intervals of 52,076 and 21,718 individuals, respectively; McDonald et
al. 2013, p. 24). The total estimated abundance of lesser prairie-
chickens in 2013 dropped to 17,616 individuals (90 percent upper and
lower confidence intervals of 20,978 and 8,442 individuals,
respectively) (McDonald et al. 2013, p. 24). The best scientific and
commercial information available supports that lesser prairie-chicken
populations have declined since pre-European settlement.
(15) Comment: Listing the lesser prairie-chicken is contrary to the
best available science and current information. Current research and
conservation efforts support that the species does not warrant listing.
Our Response: As required by section 4(b) of the Act, we used the
best scientific and commercial data available in making this final
determination. We solicited peer review from knowledgeable individuals
with scientific expertise that included familiarity with the species,
the geographic region in which the species occurs, and conservation
biology principles to ensure that our listing is based on
scientifically sound data, assumptions, and analysis. Additionally, we
requested comments or information from other concerned governmental
agencies, Native American Tribes, the scientific community, industry,
and any other interested parties concerning the proposed rule. Comments
and information we received helped inform this final rule. We used
multiple sources of information including: Results of numerous surveys,
peer-reviewed literature, unpublished reports by scientists and
biological consultants, geospatial analysis, and expert opinion from
biologists with extensive experience studying the lesser prairie-
chicken and its habitat. The commenter provides no rationale (e.g.,
literature or scientific evidence) to indicate the species does not
meet the definition of a threatened species under the Act. Please refer
to the Determination section of this final listing rule for further
discussion on whether or not the species meets the definition of an
endangered or threatened species.
(16) Comment: A final determination to list the species as
endangered or threatened would have negative impacts on economics,
communities, and private landowners. Economic impacts may affect
agriculture (farming and ranching), oil and gas, potash, dairy, wind
energy, electricity generation, mineral royalties, and transportation.
Many industries may incur additional project costs and delays due to
the regulatory and economic burden created by the listing. As industry
experiences economic impacts, commenters stated that additional impacts
could include decreased tax revenues; a reduction in jobs; effects to
school, hospital, and county government operations; increased
development pressure; and greater land fragmentation.
Our Response: For listing actions, the Act requires that we make
determinations ``solely on the basis of the best available scientific
and commercial data available'' (16 U.S.C. 1533(b)(1)(A)). Therefore,
we do not consider information concerning economic impacts when making
listing determinations. However, section 4(b)(2) of the Act states that
the Secretary shall designate and make revisions to critical habitat on
the basis of the best available scientific data after taking into
consideration the economic impact, national security impact, and any
other relevant impact of specifying any particular area as critical
habitat. Therefore, we will consider the provisions of 4(b)(2) when we
designate critical habitat for the species in the future.
(17) Comment: The proposed listing is premature. Adequate time must
be provided to determine if conservation efforts, such as the candidate
conservation agreements with assurances (CCAAs) and the Lesser Prairie-
Chicken Range-wide Conservation Plan, are sufficient to maintain a
viable lesser prairie-chicken population.
Our Response: We recognize the significant efforts of all of our
partners in the conservation of the lesser prairie-chicken, and these
conservation efforts and the manner in which they are helping to
ameliorate threats to the species are considered in our final listing
determination. Section 4(b)(1)(A) of the Act requires us to take into
account those efforts being made by a State or foreign nation, or any
political subdivision of a State or foreign nation, to protect such
species, and we fully recognize the contributions of the State and
local programs. However, the Act requires us to make determinations
based on the best scientific and commercial data available ``at the
time of listing'' after conducting a review of the status of the
species and after taking into account those efforts, if any, being made
to protect such species.
The lesser prairie-chicken has been identified as a candidate
species since 1998. Since that time, annual candidate notices of review
have been conducted, and the scientific literature and data continued
to indicate that the lesser prairie-chicken is detrimentally impacted
by ongoing threats, and we continued to find that listing the species
was warranted. Our determination is guided by the Act and its
implementing regulations, considering the five listing factors and
using the best available scientific and commercial information.
(18) Comment: The Lesser Prairie-Chicken Range-wide Conservation
Plan effectively addresses the threats being faced by the species
throughout the range. By using voluntary, incentive-based programs, the
Range-wide Conservation Plan encourages effective management on private
lands for the lesser prairie-chicken and implements mechanisms for
industry to avoid, minimize, and mitigate impacts to the species'
habitat. These efforts effectively ameliorate the threats identified in
the proposed rule for listing and, therefore, support a not-warranted
finding.
Our Response: The Service supports the efforts of the Western
Association of Fish and Wildlife Agencies (WAFWA) in the development of
the rangewide plan and has recognized it as a landmark effort in
collaborative, rangewide planning for conservation of an at-risk
species. On October 23, 2013, the Service announced its endorsement of
the plan as a comprehensive conservation program that reflects a sound
conservation design and strategy that, when implemented, will provide a
net conservation benefit to lesser prairie-chicken. The plan includes a
strategy to address threats to the prairie-chicken throughout its
range, establishes measurable biological goals and objectives for
population and habitat, provides the framework to achieve these goals
and objectives, demonstrates the administrative and financial
mechanisms necessary for
[[Page 19980]]
successful implementation, and includes adequate monitoring and
adaptive management provisions. For these reasons, elsewhere in today's
Federal Register, we are finalizing a special rule under section 4(d)
of the Act that, among other things, specifically exempts from
regulation the take of lesser prairie-chicken if that take is
incidental to carrying out the rangewide plan.
The Service's Policy for Evaluation of Conservation Efforts When
Making Listing Decisions (PECE) provides guidance on how to evaluate
conservation efforts that have not yet been fully implemented or have
not yet demonstrated effectiveness. The policy presents criteria for
evaluating the certainty of implementation and the certainty of
effectiveness for such conservation efforts. The Service has evaluated
the rangewide plan under the PECE criteria. A summary of that
evaluation follows.
At the time of the listing decision, based upon the criteria in
PECE, the Service is uncertain concerning availability of funding and
the level of voluntary participation in the rangewide plan in the
future. At this time, the measures in the rangewide plan do not allow
the Service to conclude that the lesser prairie-chicken no longer meets
the Act's definition of a threatened or endangered species.
Additionally, due to the flexibility that is necessarily built into the
implementation of the rangewide plan, there is uncertainty about when
and where impacts and offsets will occur. Most importantly, even if the
plan is implemented in the future as written and is effective at
achieving its goals, we must be able to show that the plan has
contributed to the elimination of one or more threats to the species
identified through the 4(a)(1) analysis at the time of the listing
determination such that the species no longer meets the definition of
threatened or endangered. Largely as a result of the degree of
coordination and adaptive management built into the rangewide plan,
there is a high degree of certainty that the plan will achieve its
stated purposes of creating a net conservation benefit to the species
and moving the species towards its population goals if there is
sufficient participation and enrollment from landowners and industry.
However, generally owing to the uncertainty of the timing of
conservation delivery and the funds generated by current industry
enrollment, the rangewide plan has not eliminated or adequately reduced
the threats identified such that the species no longer meets the Act's
definition of threatened or endangered at this time, as discussed
below.
The conservation strategy employed in the rangewide plan (1)
complements and builds on existing conservation efforts (e.g., CRP),
(2) uses an ``avoid, minimize, and mitigate'' strategy to address
industry impacts, and (3) provides financial incentives to landowners
to manage lands to benefit lesser prairie-chickens. Through the
mitigation framework and application of adaptive management principles,
the rangewide plan, if enrollment is sufficient and if the plan is
appropriately managed, will provide a net conservation benefit to the
species and result in incremental improvements to the level and quality
of suitable habitat over time.
Lands to be enrolled as offsets to impacts are not necessarily
currently occupied high quality habitats, and the location of offset
units is entirely driven by the willingness of landowners to
participate. They are lands where management practices are to be
implemented that would improve the suitability of those lands for
lesser prairie-chickens. These landowners are not required to implement
identical management practices, but are rather provided a suite of
management options for their lands. Until those practices are
identified for each parcel combined with the length of the contract and
the quality and location of the lands, we have little certainty about
how much conservation uplift can be expected or in what timeframe the
benefit will accrue. Even if there would be significant enrollment of
lands into the rangewide plan in the short term, it will still take
several years for habitat improvement practices to take effect for some
of the conservation practices and for lesser prairie-chicken
populations to improve.
The effectiveness of the rangewide plan is further complicated by
the impact of continued drought on the landscape. If the current
drought subsides, the rangewide plan's improved management on lands
could result in an upturn in the status of the species. However, if the
drought persists, the rangewide plan will not create additional usable
habitat necessary for the species quickly or at all. This particular
threat is largely outside of the ability of management actions to
address; therefore, it is a threat that is not addressed by the
rangewide plan, at least over the short term. Given the particularly
dire status of the lesser prairie-chicken in 2013 due to ongoing
drought (approximately 17,000 birds estimated), this threat is of high
magnitude and immediacy. Over the longer term, the rangewide plan may
ameliorate the threat of drought by creating additional habitat so that
the birds can rebound to higher numbers that can better withstand this
threat.
Finally, the Service is uncertain concerning the potential for a
lag time between authorizing impacts, securing contracts with
landowners to apply conservation to mitigate for those impacts, and
implementing the conservation actions through those contracts. While
mitigation fees must be paid and conservation contracts must be in
place prior to impacts occurring, the rangewide plan does not require
habitat improvement or creation of suitable habitat prior to impacts
occurring. The rangewide plan grants a waiver period for the oil and
gas industry wherein while all impacts must ultimately be mitigated
for, the waiver grants oil and gas impacters the ability to develop
enrolled lands in advance of conservation delivery. The mitigation
metrics are set up such that over the life of the plan, we anticipate
improvement in the status of the species, but that some of the
conservation delivery will take at least a few years to start being
realized. At the time of the listing decision, we do not have certainty
of the timeframe and the extent of the habitat improvement.
In conclusion, we have a high level of certainty that the rangewide
plan will improve the status of the species into the future if
sufficient enrollment occurs and the plan is implemented accordingly.
However, the rangewide plan has not contributed to the elimination or
adequate reduction of the threats to the species at the current time to
the point that the species does not meet the definition of threatened
or endangered.
Public Comments
Species' Populations
(19) Comment: The proposed rule states that very little information
is available regarding lesser prairie-chicken population size prior to
1900 and further states that rangewide population estimates were almost
nonexistent until the 1960s. The lack of practical baseline population
estimates and historical population studies result in considerable data
gaps regarding the significance of population fluctuations as well as
the establishment of a trend-line on the actual population estimates of
the species. Commenters question how the Service can make a reasonable
determination that listing is warranted without historical information
prior to 1900.
[[Page 19981]]
Our Response: We recognize that data gaps exist in the estimated
historical population size of the species and in the development of
population trends for the species, but we are required by the Act to
determine whether or not the species meets the definition of an
endangered or threatened species on the basis of the best scientific
and commercial data available. We recognize that population
fluctuations are common for the lesser prairie-chicken in response to
variable weather and habitat conditions, but the best available science
supports that the overall population size has likely declined from
possibly millions of birds to current estimates of thousands of birds.
We present the best available information on population sizes in the
``Rangewide Population Estimates'' and ``State-by-State Information on
Population Status'' sections of this final determination. Under section
4(a)(1) of the Act, we determine whether a species is an endangered or
threatened species because of any of the following five factors: (A)
The present or threatened destruction, modification, or curtailment of
its habitat or range; (B) overutilization for commercial, recreational,
scientific, or educational purposes; (C) disease or predation; (D) the
inadequacy of existing regulatory mechanisms; and (E) other natural or
manmade factors affecting its continued existence. We examined the best
scientific and commercial information available regarding present and
future threats faced by the lesser prairie-chicken in the Summary of
Factors Affecting the Species. Please refer to the Determination
section of this final listing rule for further discussion.
(20) Comment: The Service incorrectly points to the effects of
inconsistent data, methods, and effort levels in existing survey and
trend data and then dismisses a study that scientifically addresses
these flaws. The Interim Assessment of Lesser Prairie-Chicken Trends
since 1997 (Hagen 2012) standardizes inconsistencies among previous
survey studies and calculates the population trend of the species from
the standardized survey data. At a minimum, the Service should explain
why it dismissed this study.
Our Response: We discuss the Hagen (2012) interim assessment in the
``Rangewide Population Estimates'' of this final listing determination.
We are reluctant to place considerable weight on this interim
assessment for several reasons, as discussed below in that section. We
evaluated all sources of the best scientific and commercial data
available and found other lines of evidence more compelling. More
specifically, the rangewide aerial survey results show that the total
estimated abundance of lesser prairie-chickens dropped from 34,440
individuals (90 percent upper and lower confidence intervals of 52,076
and 21,718 individuals, respectively) in 2012, to 17,616 individuals
(90 percent upper and lower confidence intervals of 20,978 and 8,442
individuals, respectively) in 2013 (McDonald et al. 2013, p. 24).
(21) Comment: The Service needs a scientifically sound estimate of
current lesser prairie-chicken populations and habitats to use as a
baseline to determine future population increases and to delineate
critical habitat. Similarly, the Service should define a population
threshold necessary to be considered recovered post-listing.
Our Response: In the springs of 2012 and 2013, the States, in
conjunction with the Western Association of Fish and Wildlife Agencies,
implemented a rangewide sampling framework and survey methodology. This
aerial survey protocol was developed to provide a more consistent
approach for detecting rangewide trends in lesser prairie-chicken. The
aerial surveys conducted in 2012 and 2013 provide the best estimate of
current rangewide population size of the lesser prairie-chicken. The
results of the aerial surveys are discussed in more detail in the
``Rangewide Population Estimates'' section of this final listing
determination. Recovery planning, as outlined in more detail in section
4(f)(1) of the Act, is the mechanism by which the Service determines
what is necessary for the conservation and survival of the species.
Recovery plans must include objective, measurable criteria that, when
met, would result in a determination that the species be removed from
the List of Endangered and Threatened Wildlife. As mentioned above,
recovery planning for the lesser prairie-chicken will be initiated
after the listing determination is finalized.
Species' Habitat
(22) Comment: The Service inaccurately identified the lesser
prairie-chicken's historical range in the proposed rule. Some areas
identified as historical range have never been lesser prairie-chicken
habitat.
Our Response: As required by section 4(b) of the Act, we used the
best scientific and commercial data available in this final listing
determination. The commenters provided no indication of specific areas
they believe were inaccurately identified as part of the historical
range and, similarly, provided no rationale (e.g., literature or
scientific evidence) to indicate any specific areas that should be
removed from the historical range. Please refer to the ``Historical
Range and Distribution'' section for a discussion of the best
scientific and commercial data available regarding the historical range
of the lesser prairie-chicken. In addition, please refer to our
response to comment 7 in Peer Reviewer Comments, above.
(23) Comment: Based on anecdotal evidence and specimen collections,
the actual historical range of the lesser prairie-chicken for a period
from at least 1877 through 1925 may have included from southwestern
Nebraska (northern limits) and southeastward to southwestern Missouri
(eastern limits). Given this information, the apparent ``increased
range expansion'' in Kansas is really movement back into its previous
range, and not an expansion. Additionally, this reestablishment back to
its former range appears to be within artificial habitat (i.e., CRP
grasslands).
Our Response: The extent of the historical range is an estimate,
and we, therefore, use this term and the term ``approximate'' in
referring to the historical range in this final listing rule. We also
recognize that the extent of the historical range may have fluctuated
over time, based on habitat conditions evident at any one period. The
information we present in our rule serves to reflect the estimated
extent of the historical range and provides some context with which we
can discuss the estimated occupied range. We recognize that lesser
prairie-chickens have been documented from Nebraska based on specimens
collected during the 1920s. Sharpe (1968, pp. 51, 174) considered the
occurrence of lesser prairie-chickens in Nebraska to be the result of a
short-lived range expansion facilitated by settlement and cultivation
of grain crops. Sharpe did not report any confirmed observations since
the 1920s (Sharpe 1968, entire), and no sightings have been documented
despite searches over the last 5 years in southwestern Nebraska (Walker
2011, entire). Therefore, Nebraska is not included in the delineated
historical range of the species; further, the best scientific and
commercial information available does not indicate that lesser prairie-
chickens currently occur in Nebraska.
Lawrence (1877), as cited in the comment, documented finding 30
lesser prairie-chicken specimens for sale in New York that he
ascertained had originated from southern Missouri; however, the origin
of these birds is questionable (Sharpe 1968, p. 42). This anecdotal
evidence is the only evidence that the species may have one time
occurred in Missouri; therefore, there is
[[Page 19982]]
not enough evidence to support that Missouri was within the historical
range of the species. Thus, Nebraska and Missouri are not included in
the estimated historical range of the species. However, as discussed in
our response to comment 8 above, given the historical records, we agree
that the currently occupied range in northwestern Kansas does not
represent a range expansion for lesser prairie-chicken. Instead, we
consider this to be a reoccupation of former range.
(24) Comment: The data cited and relied upon by the Service show
that previous declines in lesser prairie-chicken range have stabilized.
The Service argues that range occupation trends are key indicators in
determining whether the lesser prairie-chicken is a threatened species;
however, the data provided and utilized by Service show that, between
1980 and 2007, the occupied range increased 159 percent. The increase
over that period totaled more than 43,253 square kilometers (sq km)
(16,700 square miles (sq mi)). In its evaluation of whether the lesser
prairie-chicken range is increasing, the Service examined the period
preceding European settlement of the United States to 1980. The Service
failed to consider all range-occupancy trend data after 1980. The
Service should explain its decision to base range decline estimates on
the time period from pre-European settlement to 1980 when more recent
and reliable data were available.
Our Response: The total maximum historically occupied range prior
to European settlement is estimated to be about 466,998 sq km (180,309
sq mi), whereas the total estimated occupied range is now estimated to
encompass 70,602 sq km (27,259 sq mi) as of 2007. The currently
occupied range now represents roughly 16 percent of the estimated
historical range. This value is a close approximation because a small
portion of the range in Kansas lies outside the estimated maximum
historical range and was not included in this analysis. This is further
explained in the ``Historical Range and Distribution'' and ``Current
Range and Distribution'' sections of the rule. Thus, we based our range
decline estimates on the time period from pre-European settlement to
2007. At stated in the response to comment 7 under Peer Reviewer
Comments, above, our calculations of the loss of historical range are
an estimate and not an exact value, but they demonstrate that the range
of the lesser prairie-chicken likely has contracted substantially since
historical times. In the Summary of Factors Affecting the Species, we
provide evidence to support that the species is imperiled throughout
all of its range due to ongoing and future impacts of cumulative
habitat loss and fragmentation as a result of conversion of grasslands
to agricultural uses; encroachment by invasive, woody plants; wind
energy development; petroleum production; roads; and the presence of
manmade vertical structures. These threats are currently impacting
lesser prairie-chickens throughout their range and are projected to
continue and to increase in severity into the future.
(25) Comment: The lesser prairie-chicken does not naturally exist
in Deaf Smith County, Texas, and was incorrectly identified in the area
occupied by the species.
Our Response: In March 2007, the Texas Parks and Wildlife
Department (TPWD) reported that lesser prairie-chickens were suspected
in portions of Deaf Smith County. Aerial and road surveys conducted in
2010 and 2011 did not detect lesser prairie-chickens in Deaf Smith
County; however, in 2012, Timmer (2012, pp. 36, 125-131) observed
lesser prairie-chickens in Deaf Smith County. The western portion of
Deaf Smith County is included in the Lesser Prairie-Chicken Range-wide
Conservation Plan as part of the shinnery oak prairie (Van Pelt et al.
2013, p. 87). Based upon a review of the best scientific and commercial
information available, Deaf Smith County is included as part of the
estimated occupied range of the species.
(26) Comment: Southwest Quay County, New Mexico, is incorrectly
identified in the lesser prairie-chicken ecoregion map as being
comprised of shinnery oak prairie. There are no shinnery oak vegetative
sites within the Southwest Quay Soil and Water Conservation District.
Our Response: On http://www.regulations.gov, we provided an
estimated occupied range map as supporting information for the proposed
listing rule; although Quay County is identified in the map as part of
the estimated historical range, the current estimated occupied range
includes only very small portions of southeastern Quay County. The
ecoregion map referenced by the commenter is provided in the Lesser
Prairie-Chicken Range-wide Conservation Plan. Southeastern Quay County
is identified as part of the shinnery oak prairie in the figures
provided in the Lesser Prairie-Chicken Range-wide Conservation Plan,
but the southwestern portion of the county is not included (Van Pelt et
al. 2013, p. 80). As stated in the proposed rule, the New Mexico
Department of Game and Fish (NMDGF) reports that no leks have been
detected in northeastern New Mexico, where Quay County occurs. However,
habitat in this area appears capable of supporting lesser prairie-
chicken, but the lack of any known leks in this region since 2003
suggests that lesser prairie-chicken populations in northeastern New
Mexico, if still present, are very small.
(27) Comment: The outer extent of the currently defined range is
drawn, especially in the southeast quadrant, based on references to
places where prairie-chickens were reported to have been seen with no
documentation to indicate the resident or transient status of the
birds. Thus, the potential range of the species needs to be better
defined.
Our Response: In the ``Current Range and Distribution'' section, we
discuss the currently occupied range as provided by a cooperative
mapping effort between the Playa Lakes Joint Venture and the five State
wildlife agencies within the range of the lesser prairie-chicken. The
resulting map was provided on http://www.regulations.gov as
supplemental information to the proposed rule. We consider this mapping
effort the best scientific and commercial data available regarding the
estimated current occupied range. The commenter provided no rationale
(e.g., literature or scientific evidence) to indicate which specific
areas they believe should or should not be included in the range map.
(28) Comment: Grain production in certain areas has provided
desirable, though unnatural, feeding habitat for lesser prairie-
chickens in the past. However, changes in farming practices and decline
in grain production, rather than habitat degradation, has caused the
appearance of lesser prairie-chicken population declines.
Our Response: The Service recognizes that, when available, lesser
prairie-chickens will use cultivated grains, such as grain sorghum
(Sorghum vulgare) and corn (Zea mays), during the fall and winter
months (Snyder 1967, p. 123; Campbell 1972, p. 698; Crawford and Bolen
1976c, pp. 143-144; Ahlborn 1980, p. 53; Salter et al. 2005, pp. 4-6).
However, lesser prairie-chickens tend to predominantly rely on
cultivated grains when production of natural foods, such as acorns and
grass and forb seeds, are deficient, particularly during drought and
severe winters (Copelin 1963, p. 47; Ahlborn 1980, p. 57). Overall, the
amount of land used for crop production nationally has remained
relatively stable over the last 100 years, although the distribution
and composition have varied (Lubowski et al. 2006, p. 6; Sylvester et
al. 2013, p. 13). Despite the stability in crop
[[Page 19983]]
production, the availability of grains has not slowed the decline of
the species since pre-European settlement. As some cropland is
transitioned to non-agricultural uses, new land is being brought into
cultivation helping to sustain the relatively constant amount of
cropland in existence over that period. Nationally, the amount of
cropland that was converted to urban uses between 1982 and 1997 was
about 1.5 percent (Lubowski et al. 2006, p. 3). During that same period
nationally, about 24 percent of cultivated cropland was converted to
less intensive uses such as pasture, forest, and CRP (Lubowski et al.
2006, p. 3). Thus, a decline in grain production is not directly
associated with lesser prairie-chicken population declines.
Threats
(29) Comment: Members of the public stated that hunting is driving
the species to extinction and should be banned before listing is
enacted. Others simply stated that hunting (or overutilization) is not
a significant issue for the species or a cause for overutilization.
Our Response: Hunting programs are administered by State wildlife
agencies. Currently, lesser prairie-chicken harvest is allowed only in
Kansas. As discussed in the Hunting and Other Forms of Recreation,
Educational, or Scientific Use section of the rule, we do not consider
hunting to be a threat to the species at this time. However, as
populations become smaller and more isolated by habitat fragmentation,
their resiliency to the influence of any additional sources of
mortality will decline. Intentional hunting of the lesser prairie-
chicken will be prohibited when this listing goes into effect. Please
refer to the final 4(d) special rule published elsewhere in today's
Federal Register for an explanation of the prohibited actions, and
exceptions to those prohibitions, that are necessary and advisable for
the conservation of the lesser prairie-chicken.
(30) Comment: The proposed rule indicates that collisions with
fences are an important source of mortality, but no actual data or
numbers killed were given. Further, any risk posed by fences should be
discounted because ranchers will remove or replace fences in the
future, which could benefit lesser prairie-chickens. The most recent
data do not support that fence collision takes a significant number of
birds (Hagen 2012, entire; Grisham et al. 2012, entire). Additionally,
the Service fails to acknowledge the amount of fence removal conducted
through conservation efforts like the Wildlife Habitat Incentive
Program (WHIP).
Our Response: We provide a complete discussion of the impacts
associated with fence collisions in the Collision Mortality section of
the Summary of Factors Affecting the Species. This section also
includes metrics on collision mortality associated with fences and
other manmade structures; however, precisely quantifying the scope of
the impact of fence collisions rangewide is largely unquantified due to
a lack of relevant information. However, the prevalence of fences and
power lines within the species' range suggests these structures may
have at least localized, if not widespread, detrimental effects. While
some conservation programs, including WHIP, have emphasized removal of
unneeded fences, it is likely that a majority of existing fences will
remain on the landscape indefinitely without substantially increased
removal efforts. Existing fences likely operate cumulatively with other
mechanisms described in this rule to diminish the ability of the lesser
prairie-chicken to persist, particularly in areas with a high density
of fences.
(31) Comment: Disease and predation are not significant issues for
the lesser prairie-chicken.
Our Response: We do not consider disease or parasite infections to
be a significant factor in the decline of the lesser prairie-chicken.
However, should populations continue to decline or become more isolated
by fragmentation, even small changes in habitat abundance or quality
could have a more significant influence on the impact of parasites and
diseases. Alternatively, predation has a strong relationship with
certain anthropogenic factors, such as fragmentation, vertical
structures, and roads, and continued development is likely to increase
the effects of predation on lesser prairie-chickens beyond natural
levels. As a result, predation is likely to contribute to the declining
status of the species. This is discussed further in the Predation
section of the final rule. The commenter provides no rationale (e.g.,
literature or scientific evidence) to support his assertion that
predation is not a threat to the lesser prairie-chicken.
(32) Comment: The broad statement regarding the avian toxicity of
dimethoate (an insecticide) to lesser prairie-chickens made by the
Service is not scientifically defensible. The statement was based on a
single study that was outdated and of questionable quality and the
Service's conclusion attributing sage grouse mortality to the chemical
is not supported by the study. First, the study was on sage grouse,
which have very different behavior patterns than lesser prairie-
chickens; this makes data from a sage grouse field study a poor
surrogate for assessing risks to lesser prairie-chickens. Second, it is
unclear from the study if the source of toxicity was the application of
the insecticide to the alfalfa field or a different insecticide applied
to a nearby field prior to initiation of the study.
Our Response: We stated in the proposed rule that in the absence of
more conclusive evidence, we do not currently consider application of
insecticides for most agricultural purposes to be a threat to the
species. However, we also state the primary conclusion of the only
study we are aware of that has evaluated the use of dimethoate on
grouse species. The study finds that, of approximately 200 greater sage
grouse known to be feeding in a block of alfalfa sprayed with
dimethoate, 63 were soon found dead, and many others exhibited
intoxication and other negative symptoms (Blus et al. 1989, p. 1139).
Because lesser prairie-chickens are known to selectively feed in
alfalfa fields (Hagen et al. 2004, p. 72), there is cause for concern
that similar impacts could occur. Although we acknowledge that greater
sage grouse have different behavior patterns than the lesser prairie-
chicken, there are no peer-reviewed studies available to us that
specifically analyze the effects of insecticides on lesser prairie-
chickens. Therefore, it is reasonable to use this study to draw a broad
conclusion that similar impacts to the lesser prairie-chicken are
possible. The researchers note that a flock of about 200 sage grouse
occupied a field that was sprayed with the insecticide on August 1;
about 30 intoxicated and dead grouse were observed the following day
with the last verified insecticide-related mortality occurring on
August 12 (Blus et al. 1989, p. 1142). The study further verifies,
through brain chemistry analysis of the greater sage grouse, that at
least 10 deaths directly resulted from dimethoate (Blus et al. 1989, p.
1142). Therefore, this study represents the best available science and
provides evidence to support that insecticides may present a concern
for the lesser prairie-chicken; however, we also recognize that there
is not enough evidence provided to determine that insecticides present
a threat to the species as a whole.
(33) Comment: The proposed rule states the distance that the lesser
prairie-chicken avoids around manmade infrastructure, including a wind
turbine, is more than 1.6 km (1 mi). The Service should provide
conclusive evidence or studies that birds entirely disappear from a
habitat area due to manmade structures. The science is unclear on
[[Page 19984]]
whether or not individual birds will return to areas where wind and
transmission lines have been developed after initial construction
ceases.
Our Response: In the ``Causes of Habitat Fragmentation Within
Lesser Prairie-Chicken Range'' section, we present the results of the
following studies to provide evidence that natural vertical features
like trees and artificial above ground vertical structures such as
power poles, fence posts, oil and gas wells, towers, and similar
developments can cause general habitat avoidance and displacement in
lesser prairie-chickens and other prairie grouse: Anderson 1969,
entire; Robel 2002, entire; Robel et al. 2004, entire; Hagen et al.
2004, entire; Pitman et al. 2005, entire; Pruett et al. 2009a, entire;
and Hagen et al. 2011 entire. This avoidance behavior is presumably a
behavioral response that serves to limit exposure to predation.
The observed avoidance distances vary depending upon the type of
structure and are likely also influenced by disturbances such as noise
and visual obstruction associated with these features. According to
Robel (2002, p. 23), a single commercial-scale wind turbine creates a
habitat avoidance zone for the greater prairie-chicken that extends as
far as 1.6 km (1 mi) from the structure. Pitman et al. 2005 (pp. 1267-
1268) provides evidence to support that lesser prairie-chickens likely
exhibit a similar response to tall structures like wind turbines. These
studies do not indicate that lesser prairie-chickens will never occur
within 1.6 km (1 mi) of a manmade structure, but they provide evidence
to support that observed avoidance distances can be much larger than
the actual footprint of the structure. Thus, these structures can have
significant negative impacts by contributing to further fragmentation
of otherwise suitable habitats. As human-made structures continue to be
developed across the landscape, other factors contributing to habitat
loss and fragmentation include conversion of grasslands to agricultural
uses; encroachment by invasive, woody plants; wind energy development;
petroleum production; and roads. The cumulative effect of these factors
is readily apparent at the regional scale, causing isolation of
populations at regional, landscape, and local levels.
(34) Comment: Vodenhal et al. (2011, entire) found greater prairie-
chickens to lek, nest, brood, and remain in the proximity of a Nebraska
wind farm despite the presence of localized, towering structures. This
study is at odds with the notion of site fidelity.
Our Response: Male lesser prairie-chickens have high site fidelity
and consistently return to a particular lek site (Copelin 1963, pp. 29-
30; Hoffman 1963, p. 731; Campbell 1972, pp. 698-699). Once a lek site
is selected, males persistently return to that lek year after year
(Wiley 1974, pp. 203-204). They often will continue to use these
traditional areas even when the surrounding habitat has declined in
value (for example, concerning greater sage-grouse; see Harju et al.
2010, entire). The Service recognizes that Vodenhal et al. (2011,
unpaginated) observed greater prairie-chickens lekking near the
Ainsworth Wind Energy Facility in Nebraska since 2006. The average
distance of the observed display grounds to the nearest wind turbine
tower was 1,430 m (4,689 ft) for greater prairie-chickens. The Vodenhal
et al. (2011, unpaginated) study appears to indicate that greater
prairie-chickens may be more tolerant of wind turbine towers than other
species of prairie grouse because they continued to use areas near the
wind facility despite presence of the towers. Occurrence near these
structures may actually be due to strong site fidelity or continued use
of suitable habitat remnants, though these populations may not be able
to sustain themselves without immigration from surrounding populations
(i.e., population sink) (Hagen 2004, p. 101). Thus, we conclude that
this study supports the concept of site fidelity, as birds appear to
return to the area despite the diminished habitat quality. Other recent
research supports that vertical features, including wind turbines,
cause general habitat avoidance and displacement in lesser prairie-
chickens and other prairie grouse (Anderson 1969, entire; Robel 2002,
entire; Robel et al. 2004, entire; Hagen et al. 2004, entire; Pitman et
al. 2005, entire; Pruett et al. 2009a, entire; Hagen et al. 2011,
entire; Hovick et al. unpublished manuscript, entire).
(35) Comment: The Service relies heavily on the potential for
predation facilitated by tall structures like wind turbines without
substantial research. Predation is hypothesized to be a reason for
lesser prairie-chicken avoidance of tall structures, but this
hypothesis has not been adequately studied.
Our Response: Recent research, as cited in the final rule,
demonstrates that natural vertical features like trees and artificial,
aboveground vertical structures (such as power poles, fence posts, oil
and gas wells, towers, and similar developments) can cause general
habitat avoidance and displacement in lesser prairie-chickens and other
prairie grouse (Anderson 1969, entire; Fuhlendorf et al. 2002a, pp.
622-625; Robel 2002, entire; Robel et al. 2004, entire; Hagen et al.
2004, entire; Pitman et al. 2005, entire; Pruett et al. 2009a, entire;
Hagen et al. 2011 entire). This avoidance behavior is presumed to be a
behavioral response that serves to limit exposure to predation. We are
concerned not only with an actual increase in the impact of avian
predation, but also, and even more so, with the avoidance behavior of
the lesser prairie-chicken causing individuals to leave fragmented
areas of otherwise suitable habitats. Further discussion is provided in
the Predation and ``Causes of Habitat Fragmentation within Lesser
Prairie-Chicken Range'' sections.
(36) Comment: Studies including Toepfer and Vodehnal (2009) and
Sandercock et al. (2012) require further analysis in the listing rule.
These studies bring into question the Service's central premise that
fragmented habitat causes the species to be in danger of extinction in
the foreseeable future.
Our Response: We have added a discussion of these studies in the
Wind Power and Energy Transmission Operation and Development section,
below. The most significant impact of wind energy development on lesser
prairie-chickens is caused by the avoidance of useable space due the
presence of vertical structures (turbine towers and transmission lines)
within suitable habitat. The noise produced by wind turbines also is
anticipated to contribute to behavioral avoidance of these structures.
Avoidance of these vertical structures by lesser prairie-chickens can
be as much as 1.6 km (1 mi), resulting in large areas (814 hectares
(ha) (2,011 acres (ac)) for a single turbine) of unsuitable habitat
relative to the overall footprint of a single turbine. Where such
development has occurred or is likely to occur, these areas are no
longer suitable for lesser prairie-chicken even though many of the
typical habitat components used by lesser prairie-chicken remain.
Therefore, the significant avoidance response of the species to these
developments and the scale of current and future wind development
likely to occur within the range of the lesser prairie-chicken leads us
to conclude that wind energy development is a threat to the species,
especially when considered in combination with other habitat-
fragmenting activities.
(37) Comment: In its assessment of risks from herbicides, the
Service never acknowledges current limited use of herbicides to remove
shinnery oak and also fails to acknowledge that the New Mexico and
Texas CCAAs require reductions in herbicide use. The Service never
addresses the Grisham (2012) 10-
[[Page 19985]]
year study, which ``. . . ultimately suggests that reduced rates of
herbicide and short-duration grazing treatments are not detrimental to
lesser prairie-chicken nesting ecology.''
Our Response: Grisham (2012, p. 115) states that the low dose of
herbicide used in the study was designed to reduce, not eliminate,
shrubs; most nests maintained some form of shrub component. Grisham
caveats his management implications by stating that higher doses may be
detrimental to nesting lesser prairie-chickens because high doses
completely eliminate shinnery oak from the community (Peterson and Boyd
1998, as cited in Grisham 2012, p. 115). In their analysis of the
status of the species, the Service considered the conservation measures
currently implemented to reduce herbicide use.
(38) Comment: Although the Service seems to acknowledge that
climate change is not presently harming the lesser prairie-chicken and
will occur over the next 60 years, the available data do not support a
conclusion that any of those potential effects are foreseeable.
Alternatively, other commenters assert that the effects of climate
change needs to be more thoroughly included in the future threats that
are challenging this species, otherwise the disturbances to the
species' habitat is under-represented.
Our Response: We used the best scientific and commercial
information available to develop the analysis of climate change
presented in the proposed rule. Since the publication of the proposed
rule, Grisham et al. (2013, entire) published a new study evaluating
the influence of drought and projected climate change on the
reproductive ecology of the lesser prairie-chicken in the Southern High
Plains. They hypothesized that average daily survival would decrease
dramatically under all climatic scenarios they examined. Nest survival
from onset of incubation through hatching were predicted to be less
than or equal to 10 percent in this region within 40 years. Modeling
results indicated that nest survival would fall well below the
threshold for population persistence during that time (Grisham et al.
2013, p. 8). We have incorporated a discussion of Grisham et al. (2013,
entire) in this final rule.
Although estimates of persistence of lesser prairie-chickens
provided by Garton (2012, pp. 15-16) indicated that lesser prairie-
chickens in the Shinnery Oak Prairie Region had a relatively high
likelihood of persisting over the next 30 years, the implications of
climate change were not fully considered in his analysis, as little
information evaluating the effects of climate change on the species and
its habitat was available at that time. Predictions provided by Grisham
et al. (2013, p. 8) indicate that the prognosis for persistence of
lesser prairie-chickens within this isolated region on the southwestern
periphery of the range is considerably worse than previously predicted.
This provides further evidence that climate change is likely to
contribute to the current and future threats affecting the lesser
prairie-chicken. This new information has been added to the rule and
further supports that these impacts are likely to occur in the
foreseeable future. We anticipate that climate-induced changes in
ecosystems, including grassland ecosystems used by lesser prairie-
chickens, coupled with ongoing habitat loss and fragmentation, will
interact in ways that will amplify the individual negative effects of
these and other threats identified in this final rule (Cushman et al.
2010, p. 8). Furthermore, ongoing and future habitat fragmentation is
likely to negatively affect the species' ability to respond to climate
change.
Conservation Efforts
(39) Comment: The effect of the Wind Energy Habitat Conservation
Plan (HCP) on the need to list the species is not adequately discussed.
The Service failed to analyze the expected positive impact of the HCP
on lesser prairie-chicken populations.
Our Response: The Service anticipates that the conservation program
of the Great Plains Wind Energy HCP could involve measures such as
acquisition and setting aside of conservation or mitigation lands. A
draft HCP was submitted for review by the Service and State agency
partners in November of 2013, but is not expected to be completed until
the fall of 2015. Thus, this conservation effort is still in the
development phase, and the HCP has not yet been formalized. The future
of the HCP and its potential contribution to lesser prairie-chicken
conservation is unclear at this time, and we cannot conclude that these
efforts will be finalized as they are in draft form at this time. The
HCP is further discussed in the Multi-State Conservation Efforts
section of this final rule.
(40) Comment: The proposal for listing should better recognize
current and ongoing voluntary conservation efforts in addition to
conservation measures that are in place to minimize potential adverse
effects resulting from activities including livestock grazing,
pesticide use, and oil and gas development.
Our Response: We analyzed the best scientific and commercial
information available on both conservation efforts and conservation
measures intended to minimize potential adverse effects to the species
and its habitat. Where commenters provided additional specific
information for us to consider, we have included that information in
our consideration of the status of the species in the development of
this final rule. In most instances, however, the commenters did not
provide specific information on additional conservation efforts and
measures that warrant further consideration. Without this information,
we cannot specifically address these concerns.
Service Policy
(41) Comment: An environmental impact statement should be prepared
to assess the social and economic impact of endangered or threatened
listing.
Our Response: As stated in the proposed rule, we have determined
that environmental assessments and environmental impact statements need
not be prepared in connection with regulations adopted under section
4(a)(1) of the Act. We published a notice outlining our reasons for
this determination in the Federal Register on October 25, 1983 (48 FR
49244).
(42) Comment: The Service has not adequately defined ``foreseeable
future'' as it relates to the status of the lesser prairie-chicken. The
Service needs to establish the ``foreseeable future'' as a period of
years. In addition, the Service's discussion of foreseeable future and
the status of the lesser prairie-chicken uses vague terms (e.g., ``near
term,'' ``near future'') that suggest an undefined future point in time
marks the point where the species passes from not being on the brink of
extinction to being on the brink of extinction.
Our Response: The Act does not define the term ``foreseeable
future,'' and the Act and its implementing regulations do not require
the Service to quantify the time period of foreseeable future. Further,
in a 2009 memorandum (M-37021, January 16, 2009) addressed to the
Acting Director of the Service, the Office of the Solicitor, Department
of the Interior, concluded that ``as used in the [Act], Congress
intended the term `foreseeable future' to describe the extent to which
the Secretary can reasonably rely on predictions about the future in
making determinations about the future conservation status of the
species.'' The memorandum (M-37021, January 16, 2009) goes on to state,
``the foreseeable future is not necessarily reducible to a particular
number of years. Rather, it relates to the
[[Page 19986]]
predictability of the impact or outcome for the specific species in
question. . . . Such definitive quantification, however, is rarely
possible and not required for a `foreseeable future' analysis.'' In
assessing the status of the lesser prairie-chicken, we applied the
general understanding of ``in danger of extinction'' discussed in the
December 22, 2010, memo to the polar bear listing determination file,
``Supplemental Explanation for the Legal Basis of the Department's May
15, 2008, Determination of Threatened Status for the Polar Bear,''
signed by then Acting Director Dan Ashe (hereafter referred to as Polar
Bear Memo). A complete discussion of how the Service has applied these
terms to the lesser prairie-chicken is provided in the Determination
section.
(43) Comment: The Service failed to evaluate whether the species is
endangered within any significant portion of its range. The lesser
prairie-chicken's 81-percent decline in Texas, from 236,000 sq km to
12,000 sq km (91,120 sq mi to 4,633 sq mi) and 94 percent in New Mexico
(mostly in the mixed grass prairie Bird Conservation Region) clearly
qualifies the species for protection as endangered based on threats
within a significant portion of its range.
Our Response: Under the Act and our implementing regulations, a
species may warrant listing if it is endangered or threatened
throughout all or a significant portion of its range. To determine
whether or not a species is endangered or threatened, we evaluate the
five listing factors, which include ``the present or threatened
destruction, modification, or curtailment of its habitat or range.''
The historical decline of the species' range, while highly relevant in
considering the existence or effect of threats to the species in its
current range, cannot itself be the basis for listing. In the
Determination section, below, we outline that the ongoing and future
impacts of cumulative habitat loss and fragmentation are the primary
threats to the species. These impacts are the result of conversion of
grasslands to agricultural uses; encroachment by invasive, woody
plants; wind energy development; petroleum production; roads; and
presence of manmade vertical structures, including towers, utility
lines, fences, turbines, wells, and buildings. The threats to the
survival of the lesser prairie-chicken occur with equal force
throughout all of the species' remaining range and are not restricted
to any particular portion of its currently occupied range. In other
words, there is no indication that the threat of fragmentation occurs
with greater or lesser force in any portion of the species' range.
Accordingly, our assessments and determinations apply to this species
throughout its entire range.
(44) Comment: The Service should revise its listing proposal to
establish several distinct population segments (DPSs) of the lesser
prairie-chicken in the final rule and list each DPS as endangered,
threatened, or not warranted depending on the best available science.
Our Response: Commenters generally did not provide specific
information as to what populations they felt meet the definition of a
DPS; thus, we cannot analyze what the commenter presumes to be a DPS.
We specifically discuss this issue as it relates to the Kansas
population of lesser prairie-chicken in our response to comment 3 in
Peer Reviewer Comments, above. Please refer to the Determination
section of this final listing rule for further discussion.
(45) Comment: Prohibiting actions on private lands as a result of
listing the species as threatened or endangered will constitute an
uncompensated taking under the Eminent Domain Law and would impair
private property rights. The Service should include better data on the
social and economic values of private enterprise and private property
rights.
Our Response: Listing a species as threatened or endangered does
not affect constitutionally protected property rights (see the Fifth
Amendment to the U.S. Constitution). Executive Order 12630 (Government
Actions and Interference with Constitutionally Protected Private
Property Rights) requires that we analyze the potential takings
implications of designating critical habitat for a species in a takings
implications assessment. However, the listing of a species does not
affect property rights, and, therefore, an assessment of potential
takings of land is not necessary.
(46) Comment: The proposed rule is devoid of a discussion of
whether the lesser prairie-chicken is still warranted-but-precluded
from listing due to higher priority listing actions and what changed
since earlier warranted but precluded findings for this species that
now led to the issuance of a proposed rule. The Service should consider
and document examples of changes in the basis that would justify not
continuing to make a warranted-but-precluded finding. Such examples
would include scientific information that indicates increased threats
to the viability of the species, a change in the Service's resources to
address listing decisions since the date of the 2011 candidate notice
of review (76 FR 66370, October 26, 2011), and the absence of other
candidate species that have the same or a lower listing priority
number.
Our Response: The lesser prairie-chicken was originally identified
as a candidate for listing with a listing priority number (LPN) of 8
(63 FR 31400, June 9, 1998). In 2008, we changed the LPN for the lesser
prairie-chicken from an 8 to a 2 due to a change in the magnitude of
threats from moderate to high (73 FR 75176, December 10, 2008). The
changes in threats was primarily due to an anticipated increase in the
development of wind energy and associated placement of transmission
lines throughout the estimated occupied range of the lesser prairie-
chicken. Conversion of certain CRP lands from native grass cover to
cropland or other less ecologically valuable habitat and observed
increases in oil and gas development also were important considerations
in our decision to change the LPN. Our December 10, 2008 (73 FR 75176),
candidate notice of review, provides the factual or scientific basis
for changing the listing priority number.
(47) Comment: The proposed rule summarily dismisses conservation
measures without fairly addressing their breadth, effectiveness, and
chance of success. The Service must evaluate the conservation measures
through, among other things, PECE, and must fully consider how
conservation measures will reduce or remove threats. A fair evaluation
of the conservation efforts will demonstrate that they are sufficient
to protect the lesser prairie-chicken.
Our Response: We recognize the numerous conservation actions within
the historical range of the lesser prairie-chicken, with many focused
primarily on the currently occupied portion of the range, during the
last 10 to 15 years. See the Summary of Ongoing and Future Conservation
Actions section of this rule. PECE applies to formalized conservation
efforts that have not yet been implemented or those that have been
implemented, but have not yet demonstrated whether they are effective
at the time of listing. Conservation efforts that are being implemented
and have demonstrated effectiveness are not within the scope of PECE.
The effect of such conservation efforts on the status of a species is
considered as part of the analysis of the five listing factors in
section 4(a)(1) of the Act.
The PECE states that conservation efforts that have not yet been
implemented or those that have been implemented, but have not yet
demonstrated whether they are effective, must have reduced the threat
[[Page 19987]]
at the time of listing, rather than reducing the threat in the future.
To consider if a formalized conservation effort contributes to forming
a basis for not listing a species or for listing a species as
threatened rather than endangered, we must find that the conservation
effort is sufficiently certain to be implemented and effective so as to
have contributed to the elimination or adequate reduction of one or
more threats to the species identified through the analysis of the five
listing factors in section 4(a)(1) of the Act. PECE states that the
Service must have a high level of certainty that the conservation
effort will be implemented and effective, and has resulted in reduction
or elimination of one or more threats at the time of listing.
In this final rule, we considered whether formalized conservation
efforts are included as part of the baseline through the analysis of
the five listing factors, or are appropriate for consideration under
the PECE policy.
(48) Comment: The Service's application of the categories of
species ``in danger of extinction'' identified in the Polar Bear Memo
when determining whether to list the lesser prairie-chicken is
inappropriate in several respects. First, the Service's definition of
categories of species ``in danger of extinction'' constitutes an
improper rulemaking without adequate opportunity for notice and
comment. Second, the Service's reliance on this general categorization
is inconsistent with the Act, which requires individual analyses of the
factors affecting each species when evaluating whether listing is
warranted, and is therefore arbitrary and capricious.
Our Response: As required by section 4(a)(1) of the Act, the
Service determined whether the lesser prairie-chicken is an endangered
or threatened species based on the five listing factors. See the
Summary of Factors Affecting the Species section of this rule for our
analysis.
As outlined in our response to comment 42, above, the Polar Bear
Memo provides further guidance on the statutory difference between a
threatened species and an endangered species. This memo was not a
rulemaking document that required the opportunity for notice and
comment--its categorizations are not binding; they are merely a helpful
analytical tool. As explained more fully in the rule, the Polar Bear
Memo clarifies that if a species is in danger of extinction now, it is
an endangered species. In contrast, if it is in danger of extinction in
the foreseeable future, it is a threatened species.
Moreover, we provided the public the opportunity to comment on the
use of the Polar Bear Memo as it applies to the lesser prairie-chicken
through the publication of the proposed listing rule. We did not
receive any substantive comments providing evidence contrary to our
application of the memo to the lesser prairie-chicken. Thus, this is an
appropriate use of our guidance.
(49) Comment: Individuals requested the Service provide land
management recommendations for post-listing conservation of the species
and its habitat. Specifically, the public requested details on
compatible grazing management, predator control plans, relocation of
birds, etc.
Our Response: Management recommendations as may be necessary to
achieve conservation and survival of the species will be addressed
through recovery planning efforts. Under section 4(f)(1) of the Act, we
are required to develop and implement plans for the conservation and
survival of endangered and threatened species, unless the Secretary of
the Interior finds that such a plan will not promote the conservation
of the species. We will move to accomplish these tasks as soon as
feasible.
(50) Comment: The Service should use the same standard of review
and documentation of science as outlined in the 1994 Interagency
Cooperative Policy on Information Standards under the Act (59 FR 34271,
July 1, 1994); in many instances in the proposed rule, the Service
cites a supporting source, which cites another source as the original
scientific information.
Our Response: Without specific identification of the instances in
the proposed rule where the Service cites other sources than the
original scientific information, we are unable to provide a specific
response. However, we acknowledge that in five instances we reference
information that was cited in another document. We clearly identified
each of these five instances within the proposed rule, as well as the
final rule. In four of the five instances, we provided at least one
additional citation to support the information provided.
(51) Comment: The Service cites multiple masters' theses in the
proposed rule, and these documents are not peer-reviewed, published
literature. Therefore, they do not represent the best available
science.
Our Response: Our policy on information standards under the Act
(published in the Federal Register on July 1, 1994 (59 FR 34271)), the
Information Quality Act (section 515 of the Treasury and General
Government Appropriations Act for Fiscal Year 2001 (Pub. L. 106-554;
H.R. 5658)), and our associated Information Quality Guidelines, provide
criteria, establish procedures, and provide guidance to ensure that our
decisions are based on the best scientific data available. Information
sources may include the recovery plan for the species, articles in
peer-reviewed journals, conservation plans developed by States and
counties, scientific status surveys and studies, biological
assessments, other unpublished materials, or experts' opinions or
personal knowledge. Despite the fact that these theses were not
published, they still contain credible scientific information and
represent the best scientific and commercial data available.
(52) Comment: The science for the proposed rule should be peer-
reviewed based on National Academy of Science standards for conflicts
of interest, and the Service should provide specific questions to be
addressed in the peer review.
Our Response: In accordance with our joint policy published in the
Federal Register on July 1, 1994 (59 FR 34270), we sought the expert
opinions of at least three appropriate and independent specialists
regarding the proposed rule. The purpose of such review is to ensure
that our determination of status for this species is based on
scientifically sound data, assumptions, and analyses. We invited these
peer reviewers to comment, during the public comment period, on our use
and interpretation of the science used in developing our proposal to
list the lesser prairie-chicken. Comments from these peer reviewers
have been reviewed, considered, and incorporated into this final rule,
as appropriate.
Summary of Changes From the Proposed Rule
Based upon our review of the public comments, comments from other
Federal and State agencies, peer review comments, issues addressed at
the public hearings, and any new relevant information that may have
become available since the publication of the proposal, we reevaluated
our proposed rule and made changes as appropriate. Other than minor
clarifications and incorporation of additional information on the
species' biology, this determination differs from the proposal by:
(1) Based on comments and our analyses of the available literature,
we have added a section on Taxonomy of the genus Tympanuchus, with
particular emphasis on the lesser prairie-chicken.
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(2) We have updated the Summary of Ongoing and Future Conservation
Efforts section below and included an evaluation of conservation
efforts pursuant to our Policy for Evaluation of Conservation Efforts
When Making Listing Decisions (68 FR 15100, March 28, 2003).
(3) We have added a section on the influence of noise associated
with development activities.
(4) We have added information on wing loading in grouse and a
section on conservation genetics.
(5) We have also updated the ``Rangewide Population Estimates''
section to reflect the most current State survey information.
Summary of Ongoing and Future Conservation Efforts
In this section we review current efforts that are providing some
conservation benefits to the lesser prairie-chicken and describe any
significant conservation efforts that appear likely to occur in the
future. We also completed an analysis of the Western Association of
Fish and Wildlife Agencies' Lesser Prairie-Chicken Range-wide
Conservation Plan (rangewide plan), developed in association with the
Interstate Working Group, pursuant to PECE.
Numerous conservation actions have been implemented within the
historical range of the lesser prairie-chicken, many focused primarily
on the currently occupied portion of the range, during the last 10 to
15 years. In the past, prairie grouse translocation efforts have been
implemented for both conservation and recreation purposes. Releases of
prairie chickens in Hawaii may have been one of the first attempts at
relocation outside of the historical range in North America (Phillips
1928, p. 16; see ``Historical Range and Distribution'' section below).
Most releases of lesser prairie-chickens have been in an attempt to
repatriate portions of the historical range. Kansas began efforts to
raise lesser prairie-chickens in captivity during the 1950s in an
effort to secure sufficient numbers for limited releases (Coats 1955,
p. 3). Toepfer et al. (1990, entire) summarized historical attempts to
supplement or reestablish populations of prairie grouse; most met with
poor success. Prior to 1970, there had been few attempts to supplement
or reestablish populations of lesser prairie-chickens (Toepfer et al.
1990, p. 570). Kruse (1973, as cited in Toepfer et al. 1990, p. 570)
reported on a release of lesser prairie-chickens in Colorado during
1962 that was unsuccessful. Snyder et al. (1999, entire) summarized
more recent attempts to translocate prairie grouse in the United
States. They reported on two separate releases of lesser prairie-
chickens, one in Texas and one in Colorado, during the 1980s, both of
which were unsuccessful (Snyder et al. 1999, p. 429). Despite the lack
of success, translocations are becoming increasingly popular as a means
of conserving populations of rare and declining species (Bouzat et al.
2009, p. 192). Although the best available information does not
indicate any current efforts to propagate or translocate lesser
prairie-chickens, future conservation efforts may involve such
measures.
The State conservation agencies have taken a primary role in
implementation of the conservation actions described below, but several
Federal agencies and private conservation organizations have played an
important supporting role in many of these efforts. Recently, several
multi-State efforts have been initiated, and the following section
discusses the known conservation efforts for the lesser prairie-
chicken.
Multi-State Conservation Efforts
The Conservation Reserve Program (CRP), administered by the U.S.
Department of Agriculture's (USDA) Farm Service Agency (FSA) and
focused on certain agricultural landowners, has provided short-term
protection and enhancement of millions of acres within the range of the
lesser prairie-chicken. The CRP is a voluntary program that allows
eligible landowners to receive annual rental payments and cost-share
assistance to remove land from agricultural production and establish
vegetative cover for the term of the contract. Contract terms are for
10 to 15 years, and the amount and dispersion of land enrolled in CRP
fluctuates as contracts expire and new lands are enrolled. All five
States within the range of the lesser prairie-chicken have lands
enrolled in CRP. Initially, many enrolled CRP lands, except those in
Kansas, were planted in nonnative grasses as the predominant cover
type. In the State of Kansas, enrolled lands were planted in native
species of grasses as the cover type, resulting in a considerable
benefit to lesser prairie-chicken conservation. As the program has
evolved since its inception in 1985, the FSA and their conservation
partners have encouraged the use of native grasses as the predominant
cover type in CRP lands, resulting in improved conservation benefits
for lesser prairie-chickens. Use of native grasses in the CRP helps
create suitable nesting, wintering, and brood rearing habitat for the
lesser prairie-chicken.
In accordance with general CRP guidelines, crop producers can
voluntarily enroll eligible lands in 10- to 15-year contracts in
exchange for payments, incentives, and cost-share assistance to
establish appropriate vegetation on enrolled lands. Program
administrators may focus efforts on certain environmentally sensitive
lands under a continuous signup process. The State Acres for Wildlife
Enhancement program (SAFE) is a specific conservation practice utilized
under CRP to benefit high-priority wildlife species including the
lesser prairie-chicken. Landowners may elect to enroll in this program
at any time under continuous sign-up provisions. Beginning in 2008, the
SAFE program was implemented in Colorado, Kansas, New Mexico, Oklahoma,
and Texas to target grassland habitat improvement measures within the
range of the lesser prairie-chicken. These measures help improve
suitability of existing grasslands for nesting and brood rearing by
lesser prairie-chickens. Currently, there are almost 86,603 hectares
(ha) (214,000 acres (ac)) allocated for the lesser prairie-chicken SAFE
program (CP-38E) in Colorado, Kansas, New Mexico, Oklahoma, and Texas.
Allocated acres for the SAFE program vary by State and are as follows:
Colorado 8,700 ha (21,500 ac); Kansas 21,084 ha (52,100 ac); New Mexico
1,052 ha (2,600 ac); Oklahoma 6,111 ha (15,100 ac); and Texas 49,655 ha
(122,700 ac). The current status of the SAFE program, organized by
State, is provided in the State-Specific Conservation Efforts section,
below.
In 2012, the FSA announced another CRP initiative addressing highly
erodible lands. This nationwide initiative, the CRP Highly Erodible
Land Initiative, is intended to protect certain environmentally
sensitive lands by allowing landowners nationally to enroll up to
303,500 ha (750,000 ac) of lands having an erodibility index of 20 or
greater. The initiative may further contribute to the short-term
protection and enhancement of additional acres within the range of the
lesser prairie-chicken. On average, lands with an erodibility index of
20 or greater have an erosion rate that exceeds 20 tons of soil eroded
per acre per year. The term of these contracts is a 10 year period. The
FSA, based on an analysis by Playa Lakes Joint Venture, estimates that
there are 278,829 ha (689,000 ac) of active cropland with an
erodibility index of 20 or higher remaining within the estimated
occupied range of the lesser prairie-chicken (FSA 2013, p. 41). The
vast majority of these lands occur in
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eastern New Mexico, the west Texas panhandle, western Oklahoma, and
southwestern Kansas. More detailed information on the CRP is provided
in the ``Conservation Reserve Program (CRP)'' section below.
In 2010, the USDA Natural Resources Conservation Service (NRCS)
began implementation of the Lesser Prairie-Chicken Initiative (LPCI).
The LPCI strategically provides conservation assistance, both technical
and financial, to landowners throughout the LPCI's action area, which
encompasses the lesser prairie-chicken's estimated occupied range plus
a 16-km (10-mi) buffer. The LPCI focuses on maintenance and enhancement
of suitable habitat while benefiting agricultural producers by
maintaining the farming and ranching operations throughout the region.
Twenty-seven different practices, under the core conservation practice
Upland Wildlife Habitat Management (645), are used in implementation of
the LPCI. Examples of the various practices, which are explained in
more detail in the November 22, 2013, conference opinion described
below, include prescribed grazing, prescribed burning, and the
management or removal of woody plants including invasive species. These
practices are applied or maintained annually for the life of the
practice, typically 1 to 15 years, to treat or manage habitat for
lesser prairie-chickens.
The LPCI and related NRCS activities were the focus on the November
22, 2013, conference opinion that the NRCS developed in coordination
with the Service. In the conference opinion, the Service states that
implementation of the NRCS conservation practices and their associated
conservation measures described in the conference opinion are
anticipated to result in a positive population response by the species
by reducing or eliminating adverse effects. Furthermore, the Service
states that overwhelming conservation benefits of implementation of the
proposed action within selected priority areas, maintenance of existing
habitat, and enhancement of marginal habitat will outweigh short-term
negative impacts to individual lesser prairie-chickens. Implementation
of the LPCI is expected to result in: Management of threats that
adversely affect populations, an increase in habitat under the
appropriate management prescriptions, and the development and
dissemination of information on the compatibility of sustainable
ranching operations with the persistence of this species across the
landscape. Through the conference opinion, the Service found that
effective implementation of conservation practice standards and
associated conservation measures for the LPCI are anticipated to result
in a positive population response by the species.
The NRCS has partnered with other stakeholders to fund, through the
Strategic Watershed Action Teams program, additional staff positions
dedicated to providing accelerated and targeted technical assistance to
landowners within the current range of the lesser prairie-chicken.
Technical assistance is voluntary help provided by NRCS that is
intended to assist non-federal land users in addressing opportunities,
concerns, and problems related to the use of natural resources and to
help land users make sound natural resource management decisions on
private, tribal, and other non-federal land. This assistance may be in
the form of resource assessment, practice design, resource monitoring,
or follow-up of installed practices. Numerous partners are involved in
the multi-state LPCI, including the State conservation agencies, the
Playa Lakes Joint Venture, and the Wood Foundation. The Environmental
Quality Incentives Program (EQIP) and the Wildlife Habitat Incentives
Program (WHIP), through the Working Lands for Wildlife partnership, are
the primary programs used to provide for conservation through the LPCI.
The lesser prairie-chicken is one of seven focal species being
addressed by the Working Lands for Wildlife partnership. Through the
Working Lands for Wildlife Partnership, participating landowners and
other cooperators who agree to adhere to the requirements of the
program are provided with regulatory predictability; they are exempted
from the Act's ``take'' prohibition of listed species for up to 30
years, as long as the covered conservation practices are maintained and
take is incidental to the implementation of these conservation
practices.
The EQIP is a voluntary program that provides financial and
technical assistance to agricultural producers through contracts up to
a maximum term of 10 years in length. These contracts provide financial
assistance to help plan and implement conservation practices that
address natural resource concerns and opportunities to improve soil,
water, plant, animal, air, and related resources on agricultural land.
Similarly, WHIP is a voluntary program designed for landowners who want
to develop and improve wildlife habitat on agricultural land, including
tribal lands. Through WHIP, NRCS may provide both technical assistance
and up to 75 percent cost-share assistance to establish and improve
fish and wildlife habitat. Cost-share agreements between NRCS and the
landowner may extend up to 15 years from the date the agreement is
signed. By entering into a contract with NRCS, the landowner agrees to
implement specified conservation actions through provisions of the
applicable Farm Bill conservation program, such as WHIP or EQIP.
Between the LPCI's inception in 2010 and the close of 2012, NRCS has
established 701 contracts on over 381,000 ha (942,572 ac), with the
majority of contracts (65 percent) and area (46 percent) under contract
occurring in Texas (Shaughnessy 2013, pp. 29-30). Over $24.5 million in
funding has been committed to implementation of the LPCI between 2010
and the close of 2012. In 2013, an additional 67 contracts were
established on about 89,272 ha (220,598 ac) (Ungerer 2013a). The
majority of the 2013 contracts were established in the estimated
occupied range in Kansas (37 contracts totaling 14,672 ha (36,256.1
ac)), although New Mexico had the largest acreage (11 contracts on
53,522 ha (132,255.8 ac)) placed under contract in 2013.
The NRCS also jointly administers the Grassland Reserve Program
with the FSA. The Grassland Reserve Program is a voluntary conservation
easement program that emphasizes, among other things, enhancement of
plant and animal biodiversity and protection of grasslands under threat
of conversion to other uses. Participants may choose a 10-, 15-, or 20-
year contract, or they may opt to establish a permanent/perpetual
conservation easement. Participants voluntarily limit future
development and cropping uses of the easement land while retaining the
right to conduct common grazing practices, through development of a
grazing management plan, and operations related to the production of
forage and seeding, subject to restrictions during nesting seasons.
Within the five lesser prairie-chicken States, there were a total of
two parcels totaling 494.5 ha (1,221.9 ac) under permanent easement,
both in Texas (Ungerer 2013b). Only one of these parcels was within a
county that included portions of the estimated occupied range. The
other, located in Armstrong County, lies within the historical range in
Texas. There also are several Wetland Reserve Program easements within
the five lesser prairie-chicken States that may include some areas of
grassland adjacent to the identified wetland resource. Several of these
parcels are within or adjacent to the estimated occupied range, but
most
[[Page 19990]]
of these parcels are small, generally less than 81 ha (200 ac) in size
(Ungerer 2013b).
The North American Grouse Partnership, in cooperation with the
National Fish and Wildlife Foundation and multiple State conservation
agencies and private foundations, have embarked on the preparation of
the prairie grouse portions of an overarching North American Grouse
Management Strategy. The Prairie Grouse Conservation Plan, which was
completed in 2007 (Vodehnal and Haufler 2007, entire), provides
recovery actions and defines the levels of funding necessary to achieve
management goals for all species of prairie grouse in North America,
including the lesser prairie-chicken. The plan uses an ecosystem
approach to address habitat needs of prairie grouse within the Great
Plains, concentrating on grassland conservation and restoration that
will provide habitat conditions for lesser prairie-chickens, among
other prairie grouse (Vodehnal and Haufler 2007, p. 1). The plan also
specifically states that, for the lesser prairie-chicken, grasslands
should be managed to protect and maintain existing tracts of native
mixed-grass, shinnery oak, and sagebrush prairies, and that
conservation efforts to retain and restore grasslands acres should
include reestablishing grassland and shrublands within the species'
range (Vodehnal and Haufler 2008, p. 16). The plan outlines
recommendations to improve CRP lands for lesser prairie-chickens, such
as converting CRP lands planted in nonnative grasses to native grass
mixes (Vodehnal and Haufler 2008, pp. 18-19). The prairie grouse
portions of this plan encompass about 26 million ha (65 million ac) of
grassland habitat in the United States and Canada. The extent to which
this strategy is being implemented for the lesser prairie-chicken is
not known.
The Lesser Prairie-Chicken Interstate Working Group (Working Group)
was formed in 1996. This group, composed largely of State agency
biologists, which is currently under the oversight of the Western
Association of Fish and Wildlife Agencies' Grassland Coordinator, meets
annually to share information on the status of the lesser prairie-
chicken, results of new research, and ongoing threats to the species.
The Working Group has played an important role in defining and
implementing conservation efforts for the lesser prairie-chicken. In
1999, they published a conservation strategy for the lesser prairie-
chicken (Mote et al. 1999, entire). Then, in 2008, the Working Group
published a lesser prairie-chicken conservation initiative (Davis et
al. 2008, entire). Most recently, the Working Group and the Western
Association of Fish and Wildlife Agencies (WAFWA) expended considerable
effort to develop the Lesser Prairie-Chicken Range-Wide Conservation
Plan (hereafter referred to as rangewide plan) that encompassed all
five States within the occupied range of the species (Van Pelt et al.
2013, entire). In October of 2013, we determined that the rangewide
plan, when implemented, would provide a net conservation benefit for
the lesser prairie-chicken, and, we, in turn, provided our endorsement
of the rangewide plan (Ashe 2013).
The rangewide plan is a voluntary conservation strategy that
establishes a mitigation framework administered by WAFWA for the
purpose of allowing plan participants the opportunity to mitigate any
unavoidable impacts of a particular development activity on the lesser
prairie-chicken and providing financial incentives to landowners who
voluntarily participate and manage their property for the benefit of
the lesser prairie-chicken. The rangewide plan specifically allocates
conservation objectives such that 25 percent of the conservation would
be in long-term agreements (over 10 years) while the remaining 75
percent of the conservation would be in short-term (5- or 10-year)
contracts. Compensation for unavoidable impacts would be provided, when
possible, through off-site mitigation actions. Within the plan, the
service areas coincide with the four ecoregions described by McDonald
et al. (2012, p. 7): The Shinnery Oak Prairie Region (eastern New
Mexico and southwest Texas panhandle), the Sand Sagebrush Prairie
Region (southeastern Colorado, southwestern Kansas, and western
Oklahoma panhandle), the Mixed Grass Prairie Region (northeastern Texas
panhandle, western Oklahoma, and south central Kansas), and the Short
Grass/CRP Mosaic region (northwestern Kansas).
Development activities that would be covered under the rangewide
plan include oil and gas development (seismic and land surveying,
construction, drilling, completion, workovers, operations and
maintenance, and remediation and restorations activities), agricultural
activities (brush management, building and maintaining fences and
livestock structures, grazing, water/windmills, disturbance practices,
and crop production), wind power, cell and radio towers, power line
activities (construction, operations and maintenance, and
decommissioning and remediation), road activities (construction,
operation and maintenance, and decommissioning and remediation), and
finally general activities (hunting, off-highway vehicle (OHV)
activity, general construction, and other land management), all of
which are further defined within the plan.
The rangewide plan identifies rangewide and ecoregional population
goals for the lesser prairie-chicken and the amount and condition of
habitat desired to achieve the population goals, including focal areas
and connectivity zones where much of the conservation would be
targeted. The rangewide population goal, based on an annual spring
average over a 10-year time frame, is set at 67,000 birds. Ecoregional
specific goals have been set at 8,000 birds in the Shinnery Oak Prairie
Region, 10,000 birds in the Sand Sagebrush Prairie Region, 24,000 birds
in the Mixed Grass Prairie Region and 25,000 birds in the Short Grass/
CRP Mosaic region. These regional goals and the overall rangewide
population goal may be adjusted after the first 10 years of
implementation using principles of adaptive management. In addition to
an adaptive management framework, the rangewide plan also identifies
specific monitoring and research needs. The plan also includes a number
of conservation measures designed to avoid, offset, or minimize
anticipated impacts of proposed developments that likely will be
implemented by those participating in the plan. The specific language
for each of the identified measures is provided in more detail within
the plan.
The rangewide plan incorporates a focal area strategy as a
mechanism to identify and target the population and habitat goals
established by the plan. This focal area strategy is intended to direct
conservation efforts into high priority areas and facilitate creation
of large blocks of quality habitat in contrast to untargeted
conservation efforts spread across larger areas that typically result
in smaller, less contiguous blocks of appropriately managed habitat.
These focal areas typically would have the following characteristics:
Average focal area size of at least 20,234 ha (50,000 ac); at least 70
percent of habitat within each focal area would be high quality, as
defined in the plan; and enhanced connectivity, with each focal area
generally located no more than 32 km (20 mi) apart and connected by
delineated zones between neighboring focal areas that would provide
suitable habitat and allow for movement between the focal areas. The
corridors connecting the focal areas also would generally have certain
characteristics: Habitat within the
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identified corridors would consist of at least 40 percent good- to
high-quality habitat; distances between existing habitat patches would
be no more than 3.2 km (2 mi) apart; and corridor widths would be at
least 8 km (5 mi), and would contain few, if any, barriers to lesser
prairie-chicken movement. The lack of an identified connection between
focal areas in the Shinnery Oak Prairie Region with focal areas in the
remaining regions is the obvious exception to the identified
guidelines. The Shinnery Oak Prairie Region is separated from the other
regions by a distance of over 300 km (200 mi) of unfavorable land uses
and very little suitable lesser prairie-chicken habitat.
Quality habitat used in determining appropriate focal areas and
connectivity zones has been defined in the rangewide plan and will not
be repeated here (Van Pelt et al. 2013, pp. 75-76). These habitat
characteristics generally consist of specific canopy covers, grass
composition and heights, and understory density that comprise quality
nesting and brood rearing habitat that may be observed within the four
regions delineated in the rangewide plan. Quality habitat as depicted
in the rangewide plan corresponds with habitat characteristics
described in the Background section of this final rule. The identified
focal areas would encompass over 2.9 million ha (7.1 million ac) and
represents approximately 36 percent of the estimated occupied range.
Since 2004, the Sutton Center has been working to reduce or
eliminate the mortality of lesser prairie-chickens due to fence
collisions on their study areas in Oklahoma and Texas. Forceful
collisions with fences during flight can cause direct mortality of
lesser prairie-chickens (Wolfe et al. 2007, pp. 96-97, 101). However,
mortality risk appears to be dependent on factors such as fencing
design (height, type, number of strands), length, and density, as well
as landscape topography and proximity of fences to habitats used by
lesser prairie-chickens. The Sutton Center has used competitive grants
and other funding sources to either physically remove unnecessary
fencing or to apply markers of their own design (Wolfe et al. 2009,
entire) to the top two strands to increase visibility of existing
fences. To date, the Sutton Center has removed or improved
approximately 335 kilometers (km) (208 miles (mi)) of barbed-wire fence
in Oklahoma and Texas. Treatments are typically concentrated within 1.6
km (1 mi) of active lesser prairie-chicken leks. Approximately 208 km
(129 mi) of unneeded fences have been removed. Collectively, these
conservation activities have the potential to significantly reduce the
threat of collision mortality on 44,110 ha (109,000 ac) of occupied
habitat.
Our Partners for Fish and Wildlife Program (PFW) initiated a
similar fence marking effort in New Mexico during 2008. Although the
amount of marked fences has not been quantified, the effort is an
important contribution to ongoing conservation efforts. The Texas PFW
program has marked 108 km (67 mi) and removed 53 km (33 mi) of fences
throughout the State of Texas through the end of 2013. The Colorado PFW
program, in association with its many partners, has marked
approximately 16 km (10 mi) of fence. However, continued fence
construction throughout the range of the lesser prairie-chicken and the
localized influence of these conservation efforts likely limits the
effectiveness of such measures at the population level.
In 2008, the Service and nine States, including the five States
encompassing the range of the lesser prairie-chicken, began working
with 17 wind energy development companies to develop a programmatic
habitat conservation plan (HCP). An HCP is a planning document required
as part of an application for a permit for incidental take of a
Federally listed species. An HCP describes the anticipated effects of
the proposed taking, how those impacts will be minimized or mitigated,
and how the HCP is to be funded. Initially, the endangered whooping
crane (Grus americana) was the primary focus of this HCP (the Great
Plains Wind Energy HCP). Since that time, the endangered interior least
tern (Sterna antillarum athalassos) and the threatened piping plover
(Charadrius melodus) have been included in ongoing planning efforts. As
planning efforts for the Great Plains Wind Energy HCP continued to move
forward, the lesser prairie-chicken was included in the list of species
to be covered by the HCP. In November 2013, a draft HCP was submitted
for review by the Service and State agency partners. The review is
ongoing, and the Service anticipates returning our initial comments
back by April 2014. The Great Plains Wind Energy HCP is intended to
provide take coverage for activities such as siting, construction,
operation, and decommissioning of wind facilities within the planning
area, which includes the whooping crane migration corridor and
wintering grounds, and the range of the lesser prairie-chicken. The
length of the permit is proposed to be 45 years. The HCP is scheduled
to be completed in the fall of 2015. We anticipate the conservation
program of the HCP could involve measures such as acquisition and
setting aside of conservation or mitigation lands.
A diverse group of stakeholders representing energy, agricultural,
and conservation industries and organizations (Stakeholders) across
five States within the occupied range of the lesser prairie-chicken, as
well as Nebraska, have recently developed a rangewide conservation plan
(Stakeholder Conservation Strategy) for the lesser prairie-chicken. The
intent of this Stakeholder Conservation Strategy is to provide a
framework for offsetting industry impacts to habitat while providing
incentives that would encourage landowners to conserve and manage
habitat to the overall benefit of the lesser prairie-chicken rangewide.
The proposed permit area includes the estimated occupied range of the
lesser prairie-chicken plus a 16-km (10-mi) buffer (EOR + 10; described
in more detail in the ``Current Range and Distribution'' section,
below), including portions of New Mexico, Colorado, Kansas, Oklahoma,
and Texas. Additionally, the planning area includes areas outside of
the estimated occupied range. Such areas would allow for population
expansion, provided implementation of appropriate conservation
initiatives that facilitate population expansion, and would extend the
reach of the overall planning area to portions of Nebraska. Member
Stakeholders include: Colorado Cattlemen's Association, Kansas Farm
Bureau, Oklahoma Farm Bureau, Texas Farm Bureau, Texas and Southwestern
Cattle Raisers Association, Plains Cotton Growers, Texas Wheat Growers
Association, Texas Watershed Management Foundation, Environmental
Defense Fund, The Nature Conservancy, Oklahoma State University, USDA
Agricultural Research Service, British Petroleum, Chesapeake Energy
Corporation, Chevron U.S.A., SandRidge Exploration and Production, and
XTO Energy/ExxonMobil. Additional companies or organizations may become
involved as the planning process proceeds.
The Stakeholder Conservation Strategy contains three primary
components: A Habitat Exchange for the lesser prairie-chicken, a
Habitat Quantification Tool (HQT) and a regional HCP for the lesser
prairie-chicken. The Habitat Exchange would consist of an independent
third party that facilitates transactions between a mitigation credit
buyer (an entity engaging in an otherwise lawful activity that impacts
lesser prairie-chicken habitat) and a mitigation credit producer (a
landowner). The credit producers
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(e.g., cattlemen, farmers, and others) would be paid on a performance
contract basis for achieving specific and measurable conservation
outcomes. The credit buyers (e.g., energy and other developers) would
be provided a predictable, effective, and timely means to achieve the
mitigation required to offset habitat impacts. The regional HCP
references the HQT as the scientifically measurable means for
determining debits and identifies the Habitat Exchange as the primary
means of securing mitigation obligations.
The American Habitat Center has submitted an application to the
Service on behalf of the above Stakeholders for a permit to support a
regional HCP pursuant to section 10 of the Act. This section 10 permit
would provide incidental take authorization for the covered activities
stipulated in the Stakeholder Conservation Strategy. The Service
currently intends to develop an environmental impact statement pursuant
to the National Environmental Policy Act (42 U.S.C. 4321 et seq.) to
solicit public comment on the Stakeholder Conservation Strategy and the
Service's pending permitting decision. A decision on issuance of the
permit is anticipated in the summer of 2014.
The Stakeholder Conservation Strategy and associated permit, if
approved, is intended to provide incidental take authorization for
covered activities, including agricultural production and energy
development. Entities wishing to gain regulatory assurances and
coverage under an incidental take permit could enroll in this regional
HCP. The Stakeholder Conservation Strategy proposes a multifaceted
approach involving avoidance, minimization using proven and defined
best management practices, mitigation of impacts through permanent and
temporary habitat preservation, restoration, and enhancement and other
measures. Adequate funding for implementation, including biological and
compliance monitoring, also would be an important component of the
Stakeholder Conservation Strategy.
Several potential conservation banking proposals, in various states
of development, are being considered over the range of the lesser
prairie-chicken. A conservation bank consists of permanently protected
lands that are conserved and permanently managed for endangered,
threatened, and other imperiled species. In exchange for permanently
protecting the land and managing it for these species, the Service
approves a specified number of habitat or species credits that the bank
owners may sell. These credits may then be used to offset adverse
impacts to these species and their habitats that occurred in other
locations.
A proposed programmatic conservation banking agreement has been
submitted by Common Ground Capital that would consist of an independent
conservation banking system intended to facilitate permanent
conservation for the lesser prairie-chicken through multiple
conservation banks located across the range of the lesser prairie-
chicken. The Service is currently reviewing this proposed banking
agreement, and, if approved, the agreement would allow the
establishment of conservation banks for the lesser prairie-chicken. The
estimated timeline for the Common Ground Capital banking agreement
approval process is spring 2014, with implementation to follow sometime
after the approval process is complete.
Other independent bankers have had informal discussions with the
Service and intend to submit additional conservation banking proposals
for permanent conservation banks in various areas within the lesser
prairie-chicken's range. The Service anticipates we will receive these
requests in the spring of 2014, with bank establishment to follow
sometime in 2014, pending full review and completion of the approval
process.
The five State conservation agencies developed an Internet-based
mapping tool, initially a pilot project under the Western Governors'
Association Wildlife Council. This tool, now known as the Southern
Great Plains Crucial Habitat Assessment Tool (CHAT), was made
accessible to the public in September 2011, and a second version of the
CHAT was developed in 2013. The CHAT is available for use by
conservation managers, industry, and the public to aid in conservation
planning for the lesser prairie-chicken. The tool identifies priority
habitat for the lesser prairie-chicken, including possible habitat
corridors linking important conservation areas. The CHAT will be an
important tool for implementation of the rangewide plan's mitigation
framework by using the CHAT categories as ratio multipliers. The CHAT
classifies areas on a scale of 1 to 4 by their relative value as lesser
prairie-chicken habitat. According to Van Pelt et al. (2013, pp. 54-
55), the CHAT 1 category is comprised of focal areas for lesser
prairie-chicken conservation; the CHAT 2 category is comprised of
corridors for lesser prairie-chicken conservation; the CHAT 3 category
is comprised of available and potential habitat, as developed through
modeling efforts; and the CHAT 4 category is comprised of the EOR + 10.
The CHAT includes other data layers that may facilitate conservation
planning, including current and historical lesser prairie-chicken
range, land cover types, oil and gas well density, presence of vertical
structures, and hexagonal summary polygon to provide users contextual
information about the surrounding landscape. The CHAT tool will be
updated annually. Use of the tool is currently voluntary but ultimately
may play an important role in guiding future development and conserving
important habitats.
Candidate Conservation Agreements (CCAs) and Candidate Conservation
Agreements with Assurances (CCAAs) are formal, voluntary agreements
between the Service and one or more parties to address the conservation
needs of one or more candidate species or species likely to become
candidates in the near future. These agreements are intended to reduce
or remove identified threats to a species. Implementing conservation
efforts before species are listed increases the likelihood that
simpler, more cost-effective conservation options are available and
that conservation efforts will succeed. Development of CCAs and CCAAs
is guided by regulations at 50 CFR 17.22(d) and 50 CFR 17.32(d).
Under a CCA, Federal managers and other cooperators
(nongovernmental organizations and lease holders) implement
conservation measures that reduce threats on Federal lands and leases.
Under a CCAA, non-federal landowners and lease holders voluntarily
provide habitat protection or enhancement measures on their lands,
thereby reducing threats to the species. A section 10(a)(1)(A)
enhancement of survival permit is issued in association with a CCAA. If
the species is later listed under the Act, the permit authorizes take
that is incidental to otherwise lawful activities specified in the
agreement, when performed in accordance with the terms of the
agreement. Further, the CCAA provides assurances that if the subject
species is later listed under the Act, participants who are
appropriately implementing certain conservation actions under the CCAA
will not be required to implement additional conservation measures.
An ``umbrella'' CCA and CCAA with the Bureau of Land Management
(BLM) in New Mexico and two ``umbrella'' CCAAs, one each in Oklahoma
and Texas, are being implemented for the lesser prairie-chicken. An
additional CCAA was previously established with a single landowner in
southwestern
[[Page 19993]]
Kansas; however, this CCAA expired in May of 2012. Under these
agreements, the participants agree to implement certain conservation
measures that are anticipated to reduce threats to lesser prairie-
chicken; improve their habitat; reduce habitat fragmentation; and
increase population stability, through increases in adult and juvenile
survivorship, nest success, and recruitment rates and reduced
mortality. Dependent upon the level of participation, expansion of the
occupied range may occur. Conservation measures typically focus on
maintenance, enhancement, or restoration of nesting and brood rearing
habitat. Some possible conservation measures include removal of
invasive, woody plants, such as Prosopis spp. (mesquite) and Juniperus
virginiana (eastern red cedar); implementation of prescribed fire;
marking of fences; removal of unneeded fences; improved grazing
management; and similar measures that help reduce the impact of the
existing threats.
On December 18, 2013, we announced receipt of an application from
WAFWA for an enhancement of survival permit associated with anticipated
implementation of another CCAA (78 FR 76639). This Rangewide Oil and
Gas Industry CCAA for the Lesser Prairie-Chicken (78 FR 76639)
incorporates measures to address impacts to the lesser prairie-chicken
from oil and gas activities on non-federal lands throughout the
species' range and provides coverage for a period of 30 years, offering
the oil and gas industry the opportunity to voluntarily conserve the
lesser prairie-chicken and its habitat while receiving assurances
provided by the Service. Within New Mexico, oil and gas operators have
the option to choose to enroll under the 2008 CCAA or the new rangewide
oil and gas CCAA. On February 28, 2014, we announced in a press release
that we had signed the CCAA, issued the enhancement of survival permit,
and released the accompanying final environmental assessment and
finding of no significant impact. When undertaking certain actions that
impact the species or its habitat, participants will be required to pay
mitigation fees; funds generated through these fees will enable
implementation of conservation actions on enrolled lands elsewhere.
This rangewide CCAA is one mechanism for implementing the rangewide
plan previously discussed.
All of the State conservation agencies and many Federal agencies
within the range of the lesser prairie-chicken conduct outreach efforts
intended to inform and educate the public about the conservation status
of the species. Many of these efforts specifically target landowners
and other interested stakeholders involved in lesser prairie-chicken
conservation. Annual festivals focused on the lesser prairie-chicken
have been held in several States (Milnesand, New Mexico; Woodward,
Oklahoma; and Canadian, Texas) and help inform and raise awareness of
lesser prairie-chickens for the public; however, the lesser prairie-
chicken festival in Milnesand, New Mexico, was cancelled in 2013 and
2014 due to low populations of lesser prairie-chickens. Often festival
participants are able to visit an active lesser prairie-chicken
breeding area to observe courtship displays. Festivals and similar
community efforts such as these can help promote the concept that
stewardship of the lesser prairie-chicken and other wildlife can
facilitate economic growth and viable farming and ranching operations.
State-Specific Conservation Efforts
Colorado
The Colorado Parks and Wildlife (CPW) hosted a workshop on the
conservation of the lesser prairie-chicken in late 2009. This workshop
provided information to local landowners and other interested parties
on conservation of the lesser prairie-chicken. Specific management
actions, such as grassland restoration and enhancement, intended to
benefit conservation of the lesser prairie-chicken were highlighted.
Subsequently, Colorado implemented a habitat improvement program (HIP)
for the lesser prairie-chicken that provides cost-sharing to private
landowners, subject to prior consultation and approval from a CPW
biologist, for enrolling fields or conducting habitat enhancements
beneficial to the species. By mid-2012, approximately 4,537 ha (11,212
ac) in the estimated occupied range had been enrolled in this program
(Van Pelt et al. 2013, p. 62). Additionally, in 2006, Colorado
initiated a wildlife habitat protection program designed to facilitate
acquisition of conservation easements and purchase of lands for the
lesser prairie-chicken and other wildlife species. The lesser prairie-
chicken was one of five priorities for 2012, and up to $14 million was
available in the program.
Currently about 4,433 ha (10,954 ac) have been enrolled under the
lesser prairie-chicken CRP SAFE continuous sign-up in Colorado. These
enrolled areas are typically recently expired CRP lands and contain
older grass stands in less than optimal habitat condition. In late
winter 2010 or early spring 2011, one-third of these enrolled lands
received a forb (broad-leaved herb other than a grass) and legume
inter-seeding consisting of dryland alfalfa and other species to
improve habitat quality. This effort is anticipated to result in the
establishment of alfalfa and additional forbs, resulting in improved
nesting and brood-rearing habitat. About 4,249 ha (10,500 ac) of the
initial 8,701 ha (21,500 ac) allocated for SAFE remain to be enrolled.
Our Partners for Fish and Wildlife Program (PFW) program has
contributed financial and technical assistance for restoration and
enhancement activities benefitting the lesser prairie-chicken in
Colorado. The PFW program has executed 14 private lands agreements
facilitating habitat restoration and enhancement for the lesser
prairie-chicken on about 9,307 ha (23,000 ac) of private lands in
southeastern Colorado.
A cooperative project between the CPW and the U.S. Forest Service
(USFS) has established several temporary grazing exclosures adjacent to
active leks on the Comanche National Grassland in an attempt to improve
nesting habitat. The efficacy of these treatments is unknown, and
further monitoring is planned to determine the outcome of these efforts
(Verquer and Smith 2011, p. 7).
In addition, more than 4,450 ha (11,000 ac) have been protected by
perpetual conservation easements held by CPW, The Nature Conservancy,
and the Greenlands Reserve Land Trust.
Kansas
The Kansas Department of Wildlife, Parks, and Tourism (KDWPT) has
targeted lesser prairie-chicken habitat improvements through various
means including the landowner incentive program (LIP), voluntary
mitigation projects for energy development, and a State-level WHIP.
Through the LIP, KDWPT provides direct technical and financial
assistance to private landowners interested in contributing to the
conservation of species in greatest conservation need, including lesser
prairie-chickens. The LIP improved about 9,118 ha (22,531 ac) for
lesser prairie-chickens during the period from 2007 to 2011. Some
examples of LIP projects include planting native grasses, brush
management efforts, and implementation of prescribed fire. Since 2008,
the KDWPT has provided $64,836 in landowner cost-share through the WHIP
for practices benefitting the lesser prairie-chicken on about 2,364 ha
(5,844 ac). Currently more than 11,662 ha (28,819 ac) of the original
allocation
[[Page 19994]]
have been enrolled under the lesser prairie-chicken CRP SAFE continuous
sign-up in Kansas. Primary practices include tree removal, prescribed
fire, grazing management (including perimeter fencing to facilitate
livestock management), and native grass establishment that will improve
lesser prairie-chicken nesting and brood rearing habitat.
Funds available through the State wildlife grants program also have
been used to benefit the lesser prairie-chicken in Kansas. The KDWPT
was awarded a 5-year State wildlife grant in 2009, focusing on lesser
prairie-chicken habitat improvements. Like several of the other States
within the range of the lesser prairie-chicken, the KDWPT partnered
with Pheasants Forever and NRCS to fund three employee positions that
provide technical assistance to private landowners participating in
conservation programs with an emphasis on practices favorable to the
lesser prairie-chicken. These employees primarily assist in the
implementation and delivery of the NRCS's LPCI in Kansas.
Additionally, KDWPT has a walk-in hunting program that was
initiated in 1995, in an effort to enhance the hunting tradition in
Kansas. The program provides hunters access to private property,
including many lands enrolled in CRP, and has become one of the most
successful access programs in the country. By 2004, more than 404,000
ha (1 million ac) had been enrolled in the program. Landowners receive
a small payment in exchange for allowing public hunting access to
enrolled lands. Payments vary by the amount of acres enrolled and
length of contract period. Conservation officers monitor the areas, and
violators are ticketed or arrested for offenses such as vandalism,
littering, or failing to comply with hunting or fishing regulations.
Such incentives, although relatively small, help encourage landowners
to provide habitat for resident wildlife species including the lesser
prairie-chicken.
The Service's PFW program has contributed financial and technical
assistance for restoration and enhancement activities that benefit the
lesser prairie-chicken in Kansas. Primary activities include control of
invasive, woody plant species, such as eastern red cedar and enhanced
use of prescribed fire to improve habitat conditions in native
grasslands. The PFW program has executed 63 private lands agreements on
about 56,507 ha (139,633 ac) of private lands benefitting conservation
of the lesser prairie-chicken in Kansas. An approved CCAA was developed
on 1,133 ha (2,800 ac) in south-central Kansas; however, this CCAA
expired in 2012.
The Comanche Pool Prairie Resource Foundation (Comanche Pool) is a
landowner-driven, nonprofit resource foundation that promotes proper
grassland management throughout the mixed-grass vegetative ecoregion of
southern Kansas and northern Oklahoma. Ranching is one of the major
land uses in this ecoregion, and ranchers have been generally receptive
to lesser prairie-chicken conservation strategies that are compatible
with their ongoing land use plans. The mission of the Comanche Pool is
to provide demonstrations, education, and consultation to other
landowners for the purpose of regenerating natural resources and
promoting the economic growth of the rural community.
The Comanche Pool has secured over $850,000 in grant funding
utilized to restore and enhance rangelands, which has been matched by
other partners. Landowner in-kind contributions of almost one million
dollars have been provided. Past rangeland improvement agreements
include 43 projects affecting over 100,000 acres of improved habitat
for the lesser prairie-chicken. Numerous project boundaries often are
shared, resulting in larger, contiguous blocks of habitat.
The Kansas Grazing Lands Coalition (KGLC) is another landowner-
driven initiative that has a mission to regenerate Kansas grazing land
resources through cooperative management, economics, ecology,
production, education, and technical assistance programs. The Service's
PFW program in Kansas has partnered with the KGLC to provide technical
guidance and financial assistance to restore and enhance native
grasslands through voluntary agreements with Kansas landowners. The
KGLC administers numerous outreach and education events for regional
grazing groups and plays an integral role in conservation delivery.
They coordinate with other conservation organizations in Kansas.
Lesser prairie-chicken habitat benefits from periodic burns that
improve habitat quality and various organizations in Kansas support the
use of prescribed fire. The Kansas Prescribed Burn Association (KPBA)
is a not-for-profit burn association that serves to encourage the use
of prescribed fire and is comprised of private landowners. The mission
of KPBA is to promote better rangeland management practices through the
use of prescribed fire, with emphasis on safety and training for those
members and associates with less experience in prescribed fire and
adherence to the use of standard prescribed burning practices. The
Kansas Prescribed Fire Council (KPFC) also works to support prescribed
burning in Kansas by promoting safe, legal, and responsible use of
prescribed fire as a natural resource tool through information exchange
and prescribed fire advocacy. The Comanche Pool, KGLC and KPFC recently
were awarded a National Fish and Wildlife Foundation grant to support
two prescribed fire specialist positions within the mixed grass and
sand sagebrush ecoregions of Kansas to support lesser prairie-chicken
habitat maintenance and restoration on private lands.
In 2013, a coalition of 29 county governments in Kansas joined in
an effort to coordinate conservation for the lesser prairie-chicken.
The involved counties encompass 64,954 sq km (25,079 sq mi) in western
and southern Kansas, including most of the estimated occupied range of
the lesser prairie-chicken in Kansas. In August of 2013, this coalition
prepared a conservation, management, and study plan for the lesser
prairie-chicken (Kansas Natural Resource Coalition 2013, entire). The
plan summarizes some of the available information regarding lesser
prairie-chickens and has the stated goal of preserving, maintaining,
and increasing lesser prairie-chicken populations in balance with and
respect for human, private, and industrial systems within the 29 county
region under governance by the coalition members. The plan identified
several conservation actions, such as prescribed fire, being undertaken
by the coalition or its member organizations that fall within six major
categories of conservation focus: population monitoring, habitat, nest
success, predation and interspecific competition, hunting, and program
funding.
New Mexico
In January 2003, a working group composed of local, State, and
Federal officials, along with private and commercial stakeholders, was
formed to address conservation and management activities for the lesser
prairie-chicken and dunes sagebrush lizard (Sceloporus arenicolus) in
New Mexico. This working group, formally named the New Mexico Lesser
Prairie-Chicken/Sand Dune Lizard Working Group, published the
Collaborative Conservation Strategies for the Lesser Prairie-Chicken
and Sand Dune Lizard in New Mexico (Strategy) in August 2005. This
Strategy provided guidance in the development of BLM's Special Status
Species Resource Management Plan Amendment (RMPA), approved in April
2008, which
[[Page 19995]]
also addressed the concerns and future management of lesser prairie-
chicken and dunes sagebrush lizard habitats on BLM lands, and
established the Lesser Prairie-Chicken Habitat Preservation Area of
Critical Environmental Concern. Both the Strategy and the RMPA
prescribe active cooperation among all stakeholders to reduce or
eliminate threats to these species in New Mexico. As an outcome, the
land-use prescriptions contained in the RMPA now serve as baseline
mitigation (for both species) to those operating on Federal lands or
non-federal lands with Federal minerals.
Following approval of the RMPA, a CCA was drafted by a team
including the Service, BLM, Center of Excellence for Hazardous
Materials Management, and participating cooperators. The CCA addresses
the conservation needs of the lesser prairie-chicken and dunes
sagebrush lizard on BLM lands in New Mexico by undertaking habitat
restoration and enhancement activities and by minimizing habitat
degradation. These efforts would protect and enhance existing
populations and habitats, restore degraded habitat, create new habitat,
augment existing populations of lesser prairie-chickens, restore
populations, fund research studies, or undertake other activities on
their Federal leases or allotments that improve the status of the
lesser prairie-chicken. Through this CCA, Center of Excellence for
Hazardous Materials Management will work with participating cooperators
who voluntarily commit to implementing or funding specific conservation
actions, such as burying powerlines, controlling mesquite, minimizing
surface disturbances, marking fences, and improving grazing management,
in an effort to reduce or eliminate threats to both species. The CCA
builds upon the BLM's RMPA for southeast New Mexico. The RMPA
established the foundational requirements that will be applied to all
future Federal activities, regardless of whether a permittee or lessee
participates in this CCA. The strength of the CCA comes from the
implementation of additional conservation measures that are additive,
or above and beyond those foundational requirements established in the
RMPA. In addition to the CCA, a CCAA has been developed in association
with the CCA to facilitate conservation actions for the lesser prairie-
chicken and dunes sagebrush lizard on private and State lands in
southeastern New Mexico.
Since the CCA and CCAA were finalized in December 2008, 31 oil and
gas companies have enrolled a total of 354,100 ha (875,000 ac) of
mineral holdings under the CCA and CCAA. In addition, 50 private
landowners in New Mexico have enrolled about 704,154 ha (1,740,000 ac)
under the CCAA. On March 1, 2012, the New Mexico State Land Office
enrolled all State Trust lands in lesser prairie-chicken and dunes
sagebrush lizard habitat (about 248,000 ac) into a certificate of
inclusion under the CCAA. On these enrolled State Trust lands, the
herbicide tebuthiuron will no longer be used to treat shinnery oak.
Please refer to the ``Shrub Control and Eradication'' section, below,
for more information on tebuthiuron. There currently are four pending
ranching enrollment applications being reviewed and processed for
inclusion. Recently, BLM also has closed 149,910 ha (370,435 ac) to
future oil and gas leasing and closed about 342,770 ha (847,000 ac) to
wind and solar development. Part of the purpose for these closures was
to improve lesser prairie-chicken habitat. The BLM has reclaimed about
328 ha (810 ac) of abandoned well pads and associated roads (Watts
2014, pers. comm.). The BLM also requires burial of powerlines within
3.2 km (2 mi) of leks. Approximately 52 km (32.5 mi) of aboveground
powerlines have been removed to date. Additionally, BLM has implemented
control efforts for mesquite (Prosopis glandulosa) on 157,397 ha
(388,937 ac) and has plans to do so on an additional 140,462 ha
(347,091 ac). More discussion of mesquite control is addressed in the
``Shrub Control and Eradication'' section, below.
Acquisition of land for the protection of lesser prairie-chicken
habitat also has occurred in New Mexico. The New Mexico Department of
Game and Fish (NMDGF) currently has designated 29 areas specifically
for management of the lesser prairie-chickens totaling more than 11,850
ha (29,282 ac). These areas are closed to the public during the
breeding and nesting season (March 1 to July 30) each year, and
restrictions are in place to minimize noise and other activities
associated with oil and gas drilling. In 2007, the State Game
Commission used New Mexico State Land Conservation Appropriation
funding to acquire 2,137 ha (5,285 ac) of private ranchland in
Roosevelt County. This property, the Sandhills Prairie Conservation
Area (formerly the Lewis Ranch), is located east of Milnesand, New
Mexico, and adjoins two existing Commission-owned prairie-chicken
areas. The BLM, on March 3, 2010, also acquired 3,010 ha (7,440 ac) of
land east of Roswell, New Mexico, to protect key habitat for the lesser
prairie-chicken. The Nature Conservancy owns and manages the 11,331 ha
(28,000 ac) Milnesand Prairie Preserve near Milnesand, New Mexico.
Habitat management efforts on this preserve target the lesser prairie-
chicken.
The Service's PFW program also has been active in lesser prairie-
chicken conservation efforts in the State of New Mexico. Private lands
agreements have been executed on 65 properties encompassing 28,492 ha
(70,404 ac) of lesser prairie-chicken habitat in New Mexico.
Additionally, the entire 1,052 ha (2,600 ac) allotted to the lesser
prairie-chicken CRP SAFE continuous signup in New Mexico (Lea County
only) have been enrolled under the Service's PFW program.
Oklahoma
The ODWC partnered with the Service, the Oklahoma Secretary of
Environment, The Nature Conservancy, the Sutton Center, and the Playa
Lakes Joint Venture to develop the Oklahoma Lesser Prairie-Chicken
Spatial Planning Tool in 2009. The goal of the Oklahoma Lesser Prairie-
Chicken Spatial Planning Tool is to reduce the impacts of ongoing and
planned development actions within the range of the lesser prairie-
chicken by guiding development away from sensitive habitats used by the
species. The Oklahoma Lesser Prairie-Chicken Spatial Planning Tool
assigns a relative value rank to geographic areas to indicate the value
of the area to the conservation of the lesser prairie-chicken. The
higher the rank (on a scale of 1 to 8), the more important the area is
to the lesser prairie-chicken. The Oklahoma Lesser Prairie-Chicken
Spatial Planning Tool, therefore, can be used to identify areas that
provide high-quality habitat and determine where development, such as
wind power, would have the least impact to the species. The Oklahoma
Lesser Prairie-Chicken Spatial Planning Tool also can be used to
determine a voluntary offset payment based on the cost of mitigating
the impact of the anticipated development through habitat replacement.
The voluntary offset payment is intended to be used to offset the
impacts associated with habitat loss. Use of the Oklahoma Lesser
Prairie-Chicken Spatial Planning Tool and the voluntary offset payment
is voluntary.
To date, in excess of $11.1 million has been committed to the ODWC
through the voluntary offset payment program. Most recently, the ODWC
entered into a memorandum of agreement with Chermac Energy Corporation
to partially offset potential habitat loss from a planned 88.5-km (55-
mi) high-voltage transmission line. The line would run
[[Page 19996]]
from near the Kansas State line to the Oklahoma Gas and Electric
Woodward Extra High Voltage substation and will be used to carry up to
900 megawatts of wind energy from an existing wind farm in Harper
County. The memorandum of agreement facilitates voluntary offset
payments for impacts to the lesser prairie-chicken and its habitat. The
agreement calls for the payment of a total of $2.5 million, with the
money being used to help leverage additional matching funds from
private and Federal entities for preservation, enhancement, and
acquisition of lesser prairie-chicken habitat. A large percentage of
the voluntary offset payment funds have been used to acquire lands for
the conservation of the lesser prairie-chicken and other fish and
wildlife resources.
In 2008, the ODWC acquired two properties known to be used by the
lesser prairie-chicken. The Cimarron Bluff Wildlife Management Area
encompasses 1,388 ha (3,430 ac) in northeastern Harper County,
Oklahoma. The Cimarron Hills Wildlife Management Area in northwestern
Woods County, Oklahoma, encompasses 1,526 ha (3,770 ac). The ODWC also
recently purchased 5,580 ha (13,789 ac) within the range of the lesser
prairie-chicken to expand both the Beaver River and Packsaddle Wildlife
Management Areas in Beaver and Ellis Counties, respectively.
Oklahoma State University hosts prescribed fire field days to help
inform landowners about the benefits of prescribed fire for controlling
invasion of woody vegetation in prairies and improving habitat
conditions for wildlife in grassland ecosystems. Prescribed burning is
an important tool landowners can use to improve the value of CRP fields
and native prairie for wildlife, including the lesser prairie-chicken,
by maintaining and improving vegetative structure, productivity, and
diversity and by controlling exotic plant species. In 2009, the
Environmental Defense Fund partnered with Oklahoma State University to
prepare a report on the management of CRP fields for lesser prairie-
chicken management. The document (Hickman and Elmore 2009, entire) was
designed to provide a decision tree that would assist agencies and
landowners with mid-contract management of CRP fields.
Like the other States, ODWC has partnered in the implementation of
a State WHIP designed to enhance, create, and manage habitat for all
wildlife species, including the lesser prairie-chicken. The State WHIP
recently has targeted money for lesser prairie-chicken habitat
improvements.
Several different ``Ranch Conversations'' have been held in
northwestern Oklahoma over the past 10 years, most recently hosted by
the Oklahoma High Plains Resource Development and Conservation Office.
These meetings invited private landowners and the general public to
discuss lesser prairie-chicken conservation and management, receive
information, and provide input on programs and incentives that are
available for managing the lesser prairie-chicken on privately owned
lands.
In an effort to address ongoing development of oil and gas
resources, the Oklahoma Wildlife Conservation Commission voted to
approve a memorandum of understanding with the Oklahoma Independent
Petroleum Association in February 2012 to establish a collaborative
working relationship for lesser prairie-chicken conservation. Through
this memorandum of understanding, the ODWC and Oklahoma Independent
Petroleum Association will identify and develop voluntary steps (best
management practices) that can be taken by the Oklahoma Independent
Petroleum Association's members to avoid and minimize the impacts of
their operations on the lesser prairie-chicken. These best management
practices are currently under development.
The Oklahoma Association of Conservation Districts received a USDA
Conservation Innovation Grant to develop the concept of a wildlife
credits trading program as it applies to the lesser prairie-chicken.
This pilot project entailed creating protocols for defining,
quantifying and qualifying a credit; developing a credit verification
system; and measuring the projects effect on Oklahoma's lesser prairie-
chicken population. As a part of this grant, the Oklahoma Association
of Conservation Districts currently provides financial incentives ($8
per acre) over a 5-year period to agricultural producers who enroll in
the habitat credit training program and participate in the Oklahoma
CCAA. The grant provided funding for enrollment of up to 4,046 ha
(10,000 ac) over the 5-year period, but no acres have been enrolled in
the habitat credit training program as of the end of 2013. When
completed, the credit trading program staff also will develop a
handbook that can be used by others when providing incentives to
landowners who manage their lands for conservation of the lesser
prairie-chicken and other species. The Oklahoma USDA FSA and ODWC have
worked to enroll about 2,819 ha (6,965 ac) of the 6,111 ha (15,100 ac)
allocated under the lesser prairie-chicken CRP SAFE continuous sign-up
in Beaver, Beckham, Ellis, and Harper Counties.
The ODWC, in early 2012, entered into a contract with Ecosystem
Management Research Institute to develop a conservation plan for the
lesser prairie-chicken in Oklahoma. Public comments on the draft plan
were solicited through August 30, 2012, and a final plan was completed
in September of 2012. The primary goal of the Oklahoma Lesser Prairie
Chicken Conservation Plan was to develop an overall strategy for
conservation of the lesser prairie-chicken in Oklahoma. The Oklahoma
Lesser Prairie Chicken Conservation Plan included a synthesis of all
currently available, pertinent information and input from a variety of
stakeholders. The Oklahoma Lesser Prairie Chicken Conservation Plan
also identifies priority conservation areas, population goals, and
conservation strategies and actions to improve lesser prairie-chicken
viability through habitat improvements.
As discussed above, the ODWC applied for an enhancement of survival
permit pursuant to section 10(a)(1)(A) of the Act that included a draft
umbrella CCAA between the Service and ODWC for the lesser prairie-
chicken in 14 Oklahoma counties (77 FR 37917, June 25, 2012). The draft
CCAA and associated draft environmental assessment was made available
for public review and comment from June 25, 2012 through August 24,
2012 (77 FR 37917). The CCAA was approved on January 25, 2013, and ODWC
began enrollment of private lands at that time. Since being approved,
16 landowners have enrolled 7,115 ha (17,582 ac). Several applications
are currently being reviewed and processed for enrollment. On December
20, 2013, we announced availability of a draft amendment to the
Oklahoma agricultural CCAA (78 FR 77153). This amendment would increase
acreage eligible for enrollment from 80,937 ha (200,000 ac) to 161,874
ha (400,000 ac). The comment period on this proposed amendment closed
January 21, 2014. A permitting decision is anticipated in March 2014.
The Service's PFW program also has contributed financial and
technical assistance for restoration and enhancement activities that
benefit the lesser prairie-chicken in Oklahoma. Important measures
include control of eastern red cedar and fence marking and removal to
minimize collision mortality. The Oklahoma PFW program has implemented
154 private lands agreements on about 38,954 ha (96,258 ac) of private
lands for the benefit of the lesser prairie-chicken in the State.
[[Page 19997]]
Texas
The Texas Parks and Wildlife Department (TPWD) hosted a series of
landowner meetings and listening sessions in 6 (Hemphill, Wheeler,
Gray, Bailey, Cochran, and Gaines) of the 13 counties confirmed to be
occupied by the lesser prairie-chicken in Texas. Private landowners and
the general public were invited to discuss conservation and management,
receive information, and provide input on programs and incentives that
are available for managing the lesser prairie-chicken on privately
owned lands. In response to these meetings, TPWD worked with the
Service and landowners to finalize the first Statewide umbrella CCAA
for the lesser prairie-chicken in Texas. The conservation goal of the
Texas CCAA is to encourage protection and improvement of suitable
lesser prairie-chicken habitat on non-federal lands by offering private
landowners incentives to implement voluntary conservation measures
through available funding mechanisms and by providing technical
assistance and regulatory assurances concerning land use restrictions
that might otherwise apply should the lesser prairie-chicken become
listed under the Act. The conservation measures would generally consist
of prescribed grazing; prescribed burning; brush management; cropland
and residue management; range seeding and enrollment in various Farm
Bill programs such as the CRP, the Grassland Reserve Program, and SAFE
program; and wildlife habitat treatments through the EQIP. The Texas
CCAA covers 50 counties, largely encompassing the Texas panhandle
region, and was finalized on May 14, 2009. This CCAA covers the lands
currently occupied in Texas, plus those lands that are unoccupied and
have potential habitat and those lands that could contain potential
habitat should the lesser prairie-chicken population in Texas increase.
Total landowner participation, by the close of December 2013, is 68
properties (totaling approximately 572,999 enrolled ac) in 15 counties
(Texas Parks and Wildlife Department 2014, entire). Approximately 12
applications are currently being reviewed and processed for enrollment.
In May of 2009, the TPWD, along with other partners, held an
additional five meetings in the Texas panhandle region as part of an
effort to promote lesser prairie-chicken conservation. These meetings
were intended to inform landowners about financial incentives and other
resources available to improve habitat for the lesser prairie-chicken,
including the SAFE program. The objective of the Texas SAFE program,
administered by the FSA, is to restore native mixed-grassland habitat
for the lesser prairie-chicken in Texas. The current allocation is
49,655 ha (122,700 ac), and 31,245 ha (77,209 ac) have been enrolled
through 2012. TPWD continues efforts to promote lesser prairie-chicken
conservation on private lands. In March 2010, TPWD staff conducted a 2-
day upland bird workshop where lesser prairie-chicken research and
management was discussed.
Since 2008, the NRCS and TPWD have partnered in the implementation
of an EQIP focused on lesser prairie-chicken conservation. This program
provides technical and financial assistance to landowners interested in
implementing land management practices for the lesser prairie-chicken
within its historical range. Twenty-two counties were targeted in this
initial effort, and preliminary analysis indicated that an agricultural
producer's profitability and equity could be improved by enrolling in
this program (Jones et al. 2008, p. 3).
The Service's PFW program and the TPWD have been actively
collaborating on range management programs designed to provide cost-
sharing for implementation of habitat improvements for lesser prairie-
chickens. The Service provided funding to TPWD to support a Landscape
Conservation Coordinator position for the Panhandle and Southern High
Plains region, as well as funding to support LIP projects targeting
lesser prairie-chicken habitat improvements (brush control and grazing
management) in this region. More than $200,000 of Service funds were
committed in 2010, and an additional $100,000 was committed in 2011.
Since 2008, Texas has addressed lesser prairie-chicken conservation on
5,693 ha (14,068 ac) under the LIP. Typical conservation measures
include native plant restoration, control of exotic vegetation,
prescribed burning, selective brush management, and prescribed grazing.
Currently, the PFW program has executed 66 private lands agreements on
about 53,091 ha (131,190 ac) of privately owned lands for the benefit
of the lesser prairie-chicken in Texas.
The TPWD continues to establish working relationships with wind
developers and provides review and comment on proposed developments
whenever requested. Through this voluntary comment process, TPWD
provides guidance on how to prevent, minimize, and mitigate impacts
from wind and transmission development on lesser prairie-chicken
habitat and populations.
A Lesser Prairie-Chicken Advisory Committee also has been
established in Texas and functions to provide input and information to
the State's Interagency Task Force on Economic Growth and Endangered
Species. The purpose of the task force is to provide policy and
technical assistance regarding compliance with endangered species laws
and regulations to local and regional governmental entities and their
communities engaged in economic development activities so that
compliance with endangered species laws and regulations is as effective
and cost-efficient as possible. According to the Task Force, input
provided by the Lesser Prairie-Chicken Advisory Committee serves to
help the Task Force prevent listing and minimize harm to economic
sectors if listing does occur. The advisory committee also assists in
outreach and education efforts on potential listing decisions and
methods to minimize the impact of listing.
The TPWD has worked in conjunction with several Texas universities
to fund several lesser prairie-chicken research projects. In one of
those projects, TPWD evaluated the use of aerial line transects and
forward-looking infrared technology to survey for lesser prairie-
chickens. Other ongoing research includes evaluation of lesser prairie-
chicken population response to management of shinnery oak and
evaluation of relationships among the lesser prairie-chicken, avian
predators, and oil and gas infrastructure.
In 2009, the U.S. Department of Energy awarded Texas Tech
University and the TPWD a collaborative grant to conduct aerial surveys
on approximately 75 percent of the estimated currently occupied range.
This project aided in the initial development of a standardized
protocol for conducting aerial surveys for the lesser prairie-chicken
across the entire range. All five States are currently participating in
these surveys; and a complete analysis of the results is available
(MacDonald et al. 2013, entire). A summary of the results has been
incorporated into this final rule (see ``Rangewide Population
Estimates'' section, below).
In 2007, The Nature Conservancy of Texas acquired approximately
2,428 ha (6,000 ac) of private ranchland in Yoakum and Terry Counties
for the purpose of protecting and restoring lesser prairie-chicken
habitat. This acquisition helped secure a geographically important
lesser prairie-chicken population. Since the original acquisition,
additional lands have been
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acquired, and the Yoakum Dunes Preserve now encompasses 4,342.7 ha
(10,731 ac).
In addition to participation in annual lesser prairie-chicken
festivals, the TPWD published an article on the lesser prairie-chicken
and wind development in Texas in their agency magazine in October of
2009. The TPWD and the Dorothy Marcille Wood Foundation also produced a
12-page color brochure in 2009 about the lesser prairie-chicken
entitled ``A Shared Future.''
Conservation Programs Summary
In summary, a variety of important conservation efforts have been
undertaken across the range of the lesser prairie-chicken. These
actions, as outlined above, have, at least in some instances, slowed,
but not halted, alteration of lesser prairie-chicken habitat. In many
instances, these efforts have helped reduce the severity of the threats
to the species, particularly in localized areas. Continued
implementation of these and similar future actions is crucial to lesser
prairie-chicken conservation. However, our review of these conservation
efforts indicates that most of the measures identified are not adequate
to fully address the known threats, including the primary threat of
habitat fragmentation, in a manner that effectively reduces or
eliminates the threats. All of the efforts are limited in size or
duration, and the measures typically are not implemented at a scale
that would be necessary to effectively reduce the threats to this
species across its known range. Often the measures are voluntary, with
little certainty that the measures, once implemented, will be
maintained over the long term. In a few instances, mitigation for
existing development within the range of the lesser prairie-chicken has
been secured, but the effectiveness of the mitigation is unknown.
Conservation of this species will require persistent, targeted
implementation of appropriate actions over the entire range of the
species to sufficiently reduce or eliminate the primary threats to the
lesser prairie-chicken.
Background
Species Information
The lesser prairie-chicken (Tympanuchus pallidicinctus) is a
species of prairie grouse endemic to the southern high plains of the
United States, commonly recognized for its feathered tarsi (legs),
stout build, ground-dwelling habit, and lek mating behavior. The lesser
prairie-chicken is closely related and generally similar in life
history strategy, although not identical in every aspect of behavior
and life history, to other species of North American prairie grouse
(e.g., greater prairie-chicken (T. cupido pinnatus), Attwater's
prairie-chicken (T. cupido attwateri), sharp-tailed grouse (T.
phasianellus), greater sage-grouse (Centrocercus urophasianus), and
Gunnison's sage-grouse (C. minimus)). Plumage of the lesser prairie-
chicken is characterized by a cryptic pattern of alternating brown and
buff-colored barring, and is similar in mating behavior and appearance,
although somewhat lighter in color, to the greater prairie-chicken.
Males have long tufts of feathers on the sides of the neck, termed
pinnae, which are erected during courtship displays. Pinnae are smaller
and less prominent in females. Males also display brilliant yellow
supraorbital eyecombs and dull reddish esophageal air sacs during
courtship displays (Copelin 1963, p. 12; Sutton 1977, entire; Johnsgard
1983, p. 318). A more detailed summary of the appearance of the lesser
prairie-chicken is provided in Hagen and Giesen (2005, unpaginated).
Lesser prairie-chickens are dimorphic in size, with the females
being smaller than the males (See Table 1 in Hagen and Giesen 2005,
unpaginated). Adult lesser prairie-chicken body length varies from 38
to 41 centimeters (cm) (15 to 16 inches (in)) (Johnsgard 1973, p. 275;
Johnsgard 1983, p. 318), and body mass varies from 618 to 897 grams (g)
(1.4 to 2.0 pounds (lbs)) for males and 517 to 772 g (1.1 to 1.7 lbs)
for females (Haukos et al. 1989, pp. 271; Giesen 1998, p. 14). Adults
weigh more than yearling birds.
Taxonomy
The lesser prairie-chicken is in the Order Galliformes, Family
Phasianidae, subfamily Tetraoninae, and is generally recognized as a
species separate from the greater prairie-chicken (Jones 1964, pp. 65-
73; American Ornithologist's Union 1998, p. 122). The lesser prairie-
chicken was first described as a subspecies of the greater prairie-
chicken (Ridgway 1873, p. 199) but was later named a full species in
1885 (Ridgway 1885, p. 355). As recently as the early 1980s, some
species experts (Johnsgard 1983, p. 316) still regarded the extinct
heath hen, the greater prairie-chicken, the lesser prairie-chicken, and
the Attwater's prairie-chicken to be four separate subspecies within
Tympanuchus cupido. Others, as outlined in Hagen and Giesen (2005,
unpaginated), considered the lesser prairie-chicken to be a distinct
species.
Recent molecular analyses have suggested that phylogenetic
relationships in the genus Tympanuchus remain unresolved. Ellsworth et
al. (1994, p. 664; 1995, p. 497) confirmed that the genus Tympanuchus
is distinct, but their analysis did not show strong differentiation
between the taxa within that genus. Ellsworth et al. (1994 pp. 666,
668) believed that subdivision between the prairie grouse occurred
during the recent Wisconsin glacial period and that adequate time had
not elapsed to allow sufficient genetic differentiation between the
taxa. Subsequently, Ellsworth et al. (1996, entire) expanded their
study in an attempt to resolve the evolutionary relationships among the
grouse. Yet, they were unable to partition members of the genus
Tympanuchus along typical taxonomic boundaries, likely due to
insufficient time for genetic change to accumulate (Ellsworth et al.
1996, p. 814). Similarly, Lucchini et al. (2001 p. 159) and Drovetski
(2002, p. 941) also confirmed that speciation in Tympanuchus has been
recent and may be incomplete.
While advances in molecular genetics, in many instances, have
helped clarify taxonomic relationships, some disagreement between
molecular and traditional phylogenetic approaches is not entirely
unexpected (Lucchini et al. 2001, p. 150). Several scientists have
argued that strong sexual selection characteristics of grouse that
exhibit lek mating behavior resolves the apparent lack of agreement
between the molecular data and the observed phenotypical and behavioral
differences (Ellsworth 1994, p. 669; Spaulding 2007, pp. 1083-1084;
Oyler-McCance et al. 2010, p. 121). As explained by Oyler-McCance et
al. (2010, p. 121) strong sexual selection often occurs in lekking
grouse that have highly skewed mating systems in which relatively few
males are responsible for most of the mating. In such cases, sexual
selection may drive changes in morphological and behavioral traits much
more rapidly than occurs in some genetic markers. The readily observed
differences in appearance, morphology, behavior, social interaction,
and ecological affinities facilitate reproductive isolation and
speciation within the prairie grouse. Although prairie grouse do not
yet exhibit complete reproductive isolation, as evidenced by the
presence of hybrid individuals in areas where their ranges overlap, the
incidence of hybridization appears to be low and is not significantly
impacting their gene pools (Johnsgard 2002, p. 32) (see Hybridization
section, below.
For purposes of this rule, we will follow the American
Ornithologist's
[[Page 19999]]
Union taxonomic classification, which is based on observed differences
in appearance, morphology, behavior, social interaction, and habitat
affinities. While this more traditional taxonomic approach may not
always agree with recent molecular analyses, it is widely accepted by
taxonomists, and most taxonomists agree that the lesser prairie-chicken
is distinct from other prairie grouse (Johnsgard 2002, p. 32; Johnson
2008, p. 168). Speciation is a continuous process and in lekking
grouse, where strong sexual selection is operating, males may undergo
rapid changes in morphology and behavior that can be the driving force
in speciation. Additionally, much of the observed genetic diversity in
prairie grouse is residual from when the species group originally
diverged and likely accounts for the lack of resolution reported in
previous taxonomic studies (Johnson 2008, p. 168).
Life-History Characteristics
Lesser prairie-chickens are polygynous (a mating pattern in which a
male mates with more than one female in a single breeding season) and
exhibit a lek mating system. The lek is a place where males
traditionally gather to conduct a communal, competitive courtship
display. The males use their specialized plumage and vocalizations to
attract females for mating. The sequence of vocalizations and posturing
of males, often described as ``booming, gobbling, yodeling, bubbling,
or duetting,'' has been described by Johnsgard (1983, p. 336) and
Haukos (1988, pp. 44-45) and is well summarized by Hagen and Giesen
(2005, unpaginated). Male lesser prairie-chickens gather to display on
leks at dawn and dusk beginning as early as late January and continuing
through mid-May (Copelin 1963, p. 26; Hoffman 1963, p. 730; Crawford
and Bolen 1976a, p. 97; Sell 1979, p. 10; Merchant 1982, p. 40),
although fewer numbers of birds generally attend leks during the
evening (Taylor and Guthery 1980a, p. 8). Male birds may remain on the
lek for up to 4 hours (Copelin 1963, pp. 27-28; Sharpe 1968, p. 76;
Crawford and Bolen 1975, pp. 808-810; Giesen 1998, p. 7), with females
typically departing the lek following successful copulation (Sharpe
1968, pp. 154, 156). Dominant, usually older, males occupy and defend
territories near the center of the lek where most of the copulations
occur, while younger males occupy the periphery and compete for central
access (Sharpe 1968, pp. 73-89; Wiley 1974, p. 203; Ehrlich et al.
1988, p. 259). A relatively small number of dominant males account for
the majority of copulations at each lek (Sharpe 1968, p. 87; Wiley
1974, p. 203; Locke 1992, p. 1). Young males are rarely successful in
breeding due to the dominance by older males. The spring display period
may extend into June (Hoffman 1963, p. 730; Jones 1964, p. 66);
however, Jones (1964, p. 66) observed some courtship activity as late
as July in Oklahoma.
Leks are normally located on the tops of wind-swept ridges, exposed
knolls, sparsely vegetated dunes, and similar features in areas having
low vegetation height (10 cm (4 in) or less) or bare soil and enhanced
visibility of the surrounding area (Copelin 1963, p. 26; Jones 1963a,
p. 771; Taylor and Guthery 1980a, p. 8). The features associated with
lek sites also may contribute to the transmission of sounds produced
during lekking (Sparling 1983, pp. 40-41; Butler et al. 2010, entire)
and these sounds may aid females in locating lek sites (Hagen and
Giesen 2005, unpaginated). Background noises are known to increase in
landscapes altered by human development and may interfere with normal
behavioral activities (Francis et al. 2009, p. 1415). Birds may be
particularly vulnerable to elevated levels of background noise, due to
their reliance on acoustic communication, and elevated noise levels may
negatively impact breeding in some birds particularly where acoustic
cues are used during the reproductive process (Francis et al. 2009, pp.
1415, 1418). In sage grouse, sound levels exceeding 40 decibels (dB)
were found to reduce breeding activity and increase stress, as
determined by hormone levels (Blickley et al. 2012b, p. 4-5) (See
section on Influence of Noise below).
Areas that have been previously disturbed by humans, such as
infrequently used roads, abandoned drilling pads, abandoned farmland,
recently cultivated fields, and livestock watering sites also can be
used as lek sites (Crawford and Bolen 1976b, pp. 238-239; Davis et al.
1979, pp. 81, 83; Sell 1979, p. 14; Taylor 1979, p. 707). However,
ongoing human activity, such as presence of humans or noise, may
discourage lekking by causing birds to flush, and, in some instances,
may cause lek sites to be abandoned (Hunt and Best 2004, pp. 2, 124).
Leks often are surrounded by taller, denser cover that may be used for
nesting, escape, thermal cover, and feeding cover. New leks can be
formed opportunistically at any appropriate site within or adjacent to
nesting habitat. Evidence of expanding lesser prairie-chicken
populations tends to be demonstrated by increases in the number of
active leks rather than by increases in the number of males displaying
per lek (Hoffman 1963, p. 731; Snyder 1967, p. 124; Cannon and Knopf
1981, p. 777; Merchant 1982, p. 54; Locke 1992, p. 43). Temporary or
satellite leks occasionally may be established during the breeding
season and appear indicative of population fluctuations (e.g., an
expanding population has more satellite leks than a declining
population) (Hamerstrom and Hamerstrom 1973, pp. 7, 13; Schroeder and
Braun 1992, p. 280; Haukos and Smith 1999, pp. 415, 417) or habitat
quality (Cannon and Knopf 1979, p. 44; Merrill et al. 1999, pp. 193-
194). Lesser prairie-chicken satellite leks have been observed to form
later in the breeding season and coincide with decreased attendance at
the permanent leks (Haukos and Smith 1999, p. 418). These satellite
leks consisted primarily of birds that were unable to establish
territories on the permanent leks (Haukos and Smith 1999, p. 418).
Locations of traditional, permanent lek sites also may change in
response to disturbances (Crawford and Bolen 1976b, pp. 238-240; Cannon
and Knopf 1979, p. 44).
Females arrive at the lek in early spring after the males begin
displaying, with peak hen attendance at leks typically occurring in
early to mid-April (Copelin 1963, p. 26; Hoffman 1963, p. 730; Crawford
and Bolen 1975, p. 810; Davis et al. 1979, p. 84; Merchant 1982, p. 41;
Haukos 1988, p. 49). Sounds produced by courting males serve to
advertise the presence of the lek to females in proximity to the
display ground (Robb and Schroeder 2005, p. 29). Within 1 to 2 weeks of
successful mating, the hen will select a nest site, normally within 1
to 4 km (0.6 to 2.4 mi) of an active lek (Copelin 1963, p. 44; Giesen
1994a, p. 97; Kukal 2010, pp. 19-20), construct a nest, and lay a
clutch of 8 to 14 eggs (Bent 1932, p. 282; Copelin 1963, p. 34;
Merchant 1982, p. 44; Fields 2004, pp. 88, 115-116; Hagen and Giesen
2005, unpaginated; Pitman et al. 2006a, p. 26). Nesting is generally
initiated in mid-April and concludes in late May (Copelin 1963, p. 35;
Snyder 1967, p. 124; Merchant 1982, p. 42; Haukos 1988, pp. 7-8). Hens
most commonly lay one egg per day and initiate incubation once the
clutch is complete (Hagen and Giesen 2005, unpaginated). Incubation
lasts 24 to 27 days (Coats 1955, p. 18; Sutton 1968, p. 679; Pitman et
al. 2006a, p. 26) with hatching generally peaking in late May through
mid-June (Copelin 1963, p. 34; Merchant 1982, p. 42; Pitman et al.
2006a, p. 26). Hens typically leave the nest within 24 hours after the
first egg hatches (Hagen and Giesen 2005,
[[Page 20000]]
unpaginated). Renesting may occur when the first attempt is
unsuccessful (a successful nest is one in which at least one egg
hatches) (Johnsgard 1973, pp. 63-64; Merchant 1982, p. 43; Pitman et
al. 2006a, p. 25). Renesting is more likely when nest failure occurs
early in the nesting season and becomes less common as the nesting
season progresses (Pitman et al. 2006a, p. 27). Clutches associated
with renesting attempts tend to be smaller than clutches at first
nesting (Fields 2004, p. 88; Pitman et al. 2006a, p. 27).
Nests generally consist of bowl-shaped depressions in the soil
(Giesen 1998, p. 9). Nests are lined with dried grasses, leaves, and
feathers, and there is no evidence that nests are reused in subsequent
years (Giesen 1998, p. 9). Adequate herbaceous cover, including
residual cover from the previous growing season, is an important factor
influencing nest success, primarily by providing concealment of the
nest (Suminski 1977, p. 32; Riley 1978, p. 36; Riley et al. 1992, p.
386; Giesen 1998, p. 9). Young are precocial (mobile upon hatching) and
nidifugous (typically leaving the nest within hours of hatching) (Coats
1955, p. 5). Chicks are usually capable of short flights by 14 days of
age (Hagen and Giesen 2005, unpaginated). Broods may remain with
females for up to 18 weeks (Giesen 1998, p. 9; Pitman et al. 2006c, p.
93), but brood breakup generally occurs by September when the chicks
are approximately 70 days of age (Taylor and Guthery 1980a, p. 10).
Males do not incubate the eggs, assist in chick rearing, or provide
other forms of parental care (Wiley 1974, p. 203). Nest success
(proportion of nests that hatch at least one egg) varies, but averages
about 30 percent (range 0-67 percent) (Hagen and Giesen 2005,
unpaginated).
Male lesser prairie-chickens exhibit strong site fidelity (loyalty
to a particular area; philopatry) to their display grounds (Copelin
1963, pp. 29-30; Hoffman 1963, p. 731; Campbell 1972, pp. 698-699).
Such behavior is typical for most species of prairie grouse (e.g.,
greater prairie-chicken, lesser prairie-chicken, sharp-tailed grouse,
greater sage-grouse, and Gunnison's sage-grouse) in North America
(Schroeder and Robb 2003, pp. 231-232). Once a lek site is selected,
males persistently return to that lek year after year (Wiley 1974, pp.
203-204) and may remain faithful to that site for life. They often will
continue to use these traditional areas even when the surrounding
habitat has declined in value (for example, concerning greater sage-
grouse; see Harju et al. 2010, entire). Female lesser prairie-chickens,
due to their tendency to frequently nest within 2.5 km (1.5 mi) of a
lek (Giesen 1994a, p. 97), also may display fidelity to nesting areas
but the degree of fidelity is not clearly established (Schroeder and
Robb 2003, p. 292). However, Haukos and Smith (1999, p. 418) observed
that female lesser prairie-chickens are more likely to visit older,
traditionally used lek sites than temporary, nontraditional lek sites
(those used for no more than 2 years).
Because of this fidelity to breeding areas, prairie grouse may not
immediately demonstrate a population response when faced with
environmental change. Considering that landscapes and habitat
suitability can change rapidly, strong site fidelity in prairie grouse
can result in a lag period between when a particular landscape
degradation occurs and when an associated population response is
observed (Gregory et al. 2011, pp. 29-30). In some birds exhibiting
strong philopatry, Wiens et al. (1986, p. 374) thought that the overall
response to a particular habitat alteration might not become evident
until after the most site-tenacious individuals had died. Delayed
population responses have been observed in birds impacted by wind
energy development (Stewart et al. 2007, pp. 5-6) and in greater sage-
grouse impacted by oil and gas development (Doherty et al. 2010, p. 5).
Consequently, routine lek count surveys typically used to monitor
prairie grouse may be slow in revealing impacts of environmental change
(Gregory et al. 2011, pp. 29-30).
Typically, lesser prairie-chicken home ranges (geographic area to
which an organism typically confines its activity) vary both by sex and
by season and may be influenced by a variety of factors. However, Toole
(2005, pp. 12-18) observed that home range sizes did not differ by
season, sex or age. A general lack of suitable habitats outside of
Toole's study areas may have contributed to similarity in home range
size and movements of birds within his study sites (Toole 2005, pp. 24-
28). Lesser prairie-chickens are not territorial, except for the small
area defended by males on the lek, so home ranges of individual birds
likely overlap to some extent. Habitat quality presumably influences
the extent to which individual home ranges overlap.
Males tend to have smaller home ranges than do females, with the
males generally remaining closer to the leks than do the females
(Giesen 1998, p. 11). In Colorado, Giesen (1998, p. 11) observed that
spring and summer home ranges for males were 211 ha (512 ac) and for
females were 596 ha (1,473 ac). In the spring, home ranges are fairly
small when daily activity focuses on lekking and mating. Home ranges of
nesting females in New Mexico varied, on average, from 8.5 to 92 ha (21
to 227 ac) (Merchant 1982, p. 37; Riley et al. 1994, p. 185). Jamison
(2000, p. 109) observed that range size peaked in October as birds
began feeding in recently harvested grain fields. Median range size in
October was 229 to 409 ha (566 to 1,400 ac). In Texas, Taylor and
Guthery (1980b, p. 522) found that winter monthly home ranges for males
could be as large as 1,945 ha (4,806 ac) and that subadults tended to
have larger home ranges than did adults. More typically, winter ranges
are more than 300 ha (740 ac) in size, and the size declines
considerably by spring. Based on observations from New Mexico and
Oklahoma, lesser prairie-chicken home ranges increase during periods of
drought (Giesen 1998, p. 11; Merchant 1982, p. 55), possibly because of
reduced food availability and cover. Davis (2005, p. 3) states that the
combined home range of all lesser prairie-chickens at a single lek is
about 49 square kilometers (sq km) (19 square miles (sq mi) or 12,100
ac).
Dispersal plays an important role in maintaining healthy, robust
populations by contributing to population expansion, recolonization,
and gene flow (Sutherland et al. 2000, unpaginated). Many grouse
species are known to exhibit relatively limited dispersal tendencies
and juvenile dispersal is normally less than 40 km (25 mi) (Braun et
al. 1994, pp. 432-433; Ellsworth et al. 1994, p. 666). Adults tend to
spend much of their daily and seasonal activity within 4.8 km (3.0 mi)
of a lek (Giesen 1994, p. 97; Riley et al. 1994, p. 185; Woodward et
al. 2001, p. 263). Greater sage-grouse populations, for example, were
shown to follow an isolation-by-distance model of localized gene flow
that results primarily from a tendency for individuals to move between
neighboring populations rather than through longer distance dispersal
across the range (Oyler-McCance et al. 2005, p. 1306). Similarly a
genetic analysis of greater prairie-chickens by Johnson et al. (2003,
pp. 3341-3342) revealed that greater prairie-chickens also generally
displayed isolation by distance. More recent work in Kansas concluded
that isolation by distance did not explain the distribution of genetic
diversity in greater prairie-chickens (Gregory 2011, p. 64). Instead
isolation by resistance, where landscape characteristics, primarily
habitat composition and configuration, influence the permeability of
the
[[Page 20001]]
landscape to dispersal, best described gene flow (dispersal) in greater
prairie-chickens (Gregory 2011, p. 66). Thus landscape structure and
arrangement, with its corresponding resistance to dispersal, exerts a
strong influence on dispersal and the resulting connectivity between,
and distribution of, genetic structure in greater prairie-chicken
populations (Gregory 2011, p. 68). Environmental factors also may
influence dispersal patterns in lesser prairie-chickens, particularly
in fragmented landscapes where predation rates may be higher and
habitat suitability may be reduced in smaller sized parcels. Lesser
prairie-chickens appear to be sensitive to the size of habitat
fragments and may avoid using parcels below a preferred size regardless
of habitat type or quality (see separate discussion under ``Effects of
Habitat Fragmentation'' below). As the landscape becomes more
fragmented, longer dispersal distances over areas of unsuitable
habitats may be required. However, should distances between suitable
habitat patches in fragmented landscapes exceed 50 km (31 mi), the
maximum dispersal distance observed by Hagen et al. (2004, p. 71),
dispersal may be significantly reduced. Under such conditions,
populations will become more isolated.
In lesser prairie-chickens, most seasonal movements are less than
10 km (6.2 mi), but Jamison (2000, p. 107) thought that movements as
large as 44 km (27.3 mi) might occur in fragmented landscapes. Recent
studies of lesser prairie-chicken in Kansas demonstrated some birds may
move as much as 50 km (31 mi) from their point of capture (Hagen et al.
2004, p. 71). Although recorded dispersal movements indicate that
lesser prairie-chickens are obviously physically capable of longer
distance dispersal movements, these longer movements appear to be
infrequent. Jamison (2000, p. 107) recorded only 2 of 76 tagged male
lesser prairie-chickens left the 5,760 ha (14,233 ac) primary study
area over a 3-year period. He thought site fidelity rather than habitat
was more important in influencing movements of male lesser prairie-
chickens (Jamison 2000, p. 111). A tendency to move among neighboring
populations rather than long distance dispersal over the range, as
demonstrated by greater sage-grouse (Oyler-McCance et al. 2005, p.
1306), may partially explain why lesser prairie-chickens in Kansas
recolonized areas of native grassland in CRP but past efforts to
translocate individuals over long distances have largely been
unsuccessful.
Physiology influences dispersal capabilities and also plays a role
in dispersal and movement patterns exhibited by lesser prairie-
chickens. Lesser prairie-chickens and other species of grouse are
generally considered poor fliers due to their high (heavy) wing loading
and low wing aspect (Drovetski 1996, pp. 805-806; Bevanger 1998, p.
69). Birds with high wing loading have relatively small wings compared
to their body mass. Birds with low wing aspect are those birds having
relatively short, broad wings. Fast flight and a large turning radius
are characteristic of birds with heavy wing loading (Drovetski 1996, p.
806). The combination of high wing loading and low wing aspect impacts
aerodynamic performance and limits flight maneuverability. These birds
typically are adapted to make relatively long, fast, straight and
efficient flights, spending less time in the air than is typical for
other species of birds (Drovetski, 1996, pp. 809-810). Consequently,
the combination of a heavy body with smaller wings, coupled with their
rapid flight, restricts the ability of most prairie grouse to react
swiftly to unexpected obstacles. Such birds, like the lesser prairie-
chicken, have a high risk of colliding with objects, such as powerlines
or fences, within their flight path (Bevanger 1998, p. 67).
Daily movements of males tend to increase in fall and winter and
decrease with onset of spring, with median daily movements typically
being less than 786 meters (2,578 ft) per day (Jamison 2000, pp. 106,
112). In Texas, Haukos (1988, p. 46) recorded daily movements of 0.1 km
(0.06 mi) to greater than 6 km (3.7 mi) by female lesser prairie-
chickens prior to onset of incubation. Taylor and Guthery (1980b, p.
522) documented a single male moving 12.8 km (8 mi) in 4 days, which
they considered to be a dispersal movement. Because lesser prairie-
chickens exhibit limited dispersal tendencies and do not typically
disperse over long distances, they may not readily recolonize areas
following localized extinctions, particularly where the distance
between habitat patches exceeds their typical dispersal capabilities.
In general, there is little documentation of historical dispersal
patterns, and the existence of large-scale migration movements is not
known. However, both Bent (1932, pp. 284-285) and Sharpe (1968, pp. 41-
42) thought that the species, at least historically, might have been
migratory with separate breeding and wintering ranges. Taylor and
Guthery (1980a, p. 10) also thought the species was migratory prior to
widespread settlement of the High Plains, but migratory movements have
not recently been documented. The lesser prairie-chicken is now thought
to be nonmigratory.
Lesser prairie-chickens forage during the day, usually during the
early morning and late afternoon, and roost at night (Jones 1964, p.
69). Diet of the lesser prairie-chicken is very diverse, primarily
consisting of insects, seeds, leaves, and buds and varies by age,
location, and season (Giesen 1998, p. 4). They forage on the ground and
within the vegetation layer (Jones 1963b, p. 22) and are known to
consume a variety of invertebrate and plant materials. For example, in
New Mexico, Smith (1979, p. 26) documented 30 different kinds of food
items consumed by lesser prairie-chickens. In Texas, Crawford and Bolen
(1976c, p. 143) identified 23 different plants in the lesser prairie-
chicken diet. Jones (1963a, pp. 765-766), in the Artemesia filifolia
(sand sagebrush) dominated grasslands of Oklahoma, recorded 16
different plant species eaten by lesser prairie-chickens.
Lesser prairie-chicken energy demands are almost entirely derived
from daily foraging activities rather than stored fat reserves (Giesen
1998, p. 4). Olawsky (1987, p. 59) found that, on average, lesser
prairie-chicken body fat reserves were less than 4.5 percent of body
weight. Consequently, quality and quantity of food consumed can have a
profound effect on the condition of individual birds. Inadequate food
supplies and reduced nutritional condition can affect survival,
particularly during harsh winters, and reproductive potential. Poor
condition can lead to poor performance on display grounds, impact
nesting success, and reduce overwinter survival. Sufficient nutrients
and energy levels are important for reproduction and overwintering.
Males expend energy defending territories and mating while females have
demands of nesting, incubation, and any renesting. Reduced condition
can lead to smaller clutch sizes. Because lesser prairie-chicken diets
vary considerably by age, season, and habitat type and quality, habitat
alteration can influence availability of certain foods. While not as
critical for adults, presence of forbs and associated insect
populations can be very important for proper growth and development of
chicks and poults (juvenile birds).
Generally, chicks and young juveniles tend to forage almost
exclusively on insects, such as grasshoppers and beetles, and other
animal matter while adults tend to consume a higher percentage of
vegetative material
[[Page 20002]]
(Giesen 1998, p. 4). The majority of the published diet studies have
been conducted in the southwestern portions of the historical range
where the Quercus havardii (shinnery oak) dominated grasslands are
prevalent. Throughout their range, when available, lesser prairie-
chickens will use cultivated grains, such as Sorghum vulgare (grain
sorghum) and Zea mays (corn), during the fall and winter months (Snyder
1967, p. 123; Campbell 1972, p. 698; Crawford and Bolen 1976c, pp. 143-
144; Ahlborn 1980, p. 53; Salter et al. 2005, pp. 4-6). However, lesser
prairie-chickens tend to predominantly rely on cultivated grains when
production of natural foods, such as acorns and grass and forb seeds
are deficient, particularly during drought and severe winters (Copelin
1963, p. 47; Ahlborn 1980, p. 57). Cultivated grains may be temporarily
important during prolonged periods of adverse winter weather but are
not necessary for survival during most years and in most regions. Use
of cultivated grain fields is dependent upon the availability of waste
grains on the soil surface during the fall and winter period. More
efficient harvesting methods in use today likely reduce the
availability of waste grain.
Food availability for young is most critical during the first 20
days (3 weeks) post-hatching when rapid growth is occurring (Dobson et
al. 1988, p. 59). Food shortages during critical periods will
negatively impact development and survival. Diet of lesser prairie-
chicken chicks less than 5 weeks of age is entirely composed of insects
and similar animal matter. Specifically, diet of chicks in New Mexico
that were less than 2 weeks of age was 80 percent treehoppers
(Mebracidae) (Davis et al. 1979, p. 71; Davis et al. 1980 p. 78).
Overall, chicks less than 5 weeks of age consumed predominantly (87.7
percent) short-horned grasshoppers (Acrididae), treehoppers, and long-
horned grasshoppers (Tettigonidae) (Davis et al. 1980, p. 78). Ants
(Formicidae), mantids (Mantidae), snout beetles (Curculionidae),
darkling beetles (Tenebrionidae), robber flies (Asilidae), and
cockroaches (Blattidea) collectively provided the remaining 12.3
percent of the chicks' diet (Davis et al. 1980, p. 78). Similarly
Suminski (1977, pp. 59-60) examined diet of chicks 2 to 4 weeks of age
in New Mexico and found that diet was entirely composed of insects.
Treehoppers, short-horned grasshoppers, and ants were the most
significant (95 percent) items consumed, by volume. Insects and similar
animal matter are a particularly prevalent component in the diet of
young prairie-chickens (Drake 1994, pp. 31, 34, 36). Insects are high
in protein (Riley et al. 1998, p. 42), and a high-protein diet was
essential in pheasants for normal growth and feather development
(Woodward et al. 1977. p. 1500). Insects and other arthropods also have
been shown to be extremely important in the diet of young sage grouse
and Attwater's prairie-chicken (Service 2010, pp. 30-31).
Older chicks between 5 and 10 weeks of age ate almost entirely
short-horned grasshoppers (80.4 percent) (Davis et al. 1980, p. 78).
They also began to consume plant material during this period. Shinnery
oak acorns, seeds of Lithospermum incisum (narrowleaf stoneseed), and
foliage and flowers of Commelina erecta (erect dayflower) comprised
less than 1 percent of the diet (Davis et al. 1980, p. 78).
Correspondingly, Suminski (1977, pp. 59, 61) observed that chicks
between 6 and 10 weeks of age had begun to consume very small
quantities (1.3 percent by volume) of plant material. The remainder of
the diet was still almost entirely composed of insects. By far the most
prevalent insect was short-horned grasshoppers (Acrididae), accounting
for 73.9 percent of the diet (Davis et al. 1980, p. 78). As the birds
grew, the sizes of insects eaten increased. Analysis of food habits of
juvenile birds from 20 weeks of age and older, based on samples
collected between August and December, revealed that 82.6 percent of
diet was plant material by volume and 17.4 percent was invertebrates
(Suminski 1977, p. 62). Shinnery oak acorns contributed 67 percent of
the overall diet, by volume. Key insects included crickets (Gryllidae),
short-horned grasshoppers, mantids, and butterfly (Lepidoptera) larvae.
Plant materials are a principal component of the diet for adult
lesser prairie-chickens; however, the composition of the diet tends to
vary by season and habitat type. The majority of the diet studies
examined foods contained in the crop (an expanded, muscular pouch
within the digestive tract of most birds that aids in breakdown and
digestion of foods) and were conducted in habitats supporting shinnery
oak. However, Jones (1963b, p. 20) reported on lesser prairie-chicken
diets from sand sagebrush habitats.
In the spring (March, April, and May), lesser prairie-chickens fed
heavily on green vegetation (60 to 79 percent) and mast and seeds (15
to 28 percent) (Davis et al. (1980, p. 76; Suminski 1977, p. 57).
Insects comprised less than 13 percent of the diet primarily due to
their relative scarcity in the spring months. Treehoppers and beetles
were the most common types of insects found in the spring diet. The
proportion of vegetative material provided by shinnery oak leaves,
catkins, and acorns was high. Similarly, Doerr (1980, p. 8) also
examined the spring diet of lesser prairie-chickens. However, he
compared diets between areas treated with the herbicide tebuthiuron and
untreated areas, and it is unclear whether the birds he examined came
from treated or untreated areas. Birds collected from treated areas
likely would have limited access to shinnery oak, possibly altering the
observed occurrence of shinnery oak in the diet. He reported that
animal matter was the dominant component of the spring diet and largely
consisted of short-horned grasshoppers and darkling beetles (Doerr
1980, pp. 30-31). Ants, ground beetles (Carabidae), and stinkbugs
(Pentatomidae) were slightly less prevalent in the diet. Shinnery oak
acorns and plant seeds were the least common component, by volume, in
the diet in the Doerr (1980) studies.
In the summer, insects become a more common component of the adult
diet. In New Mexico, insects comprised over half (55.3 percent) of the
overall summer (June, July, and August) diet with almost half (49
percent) of the insects being short- and long-horned grasshoppers and
treehoppers (Davis et al. 1980, p. 77). Plant material consumed was
almost equally divided between foliage (leaves and flowers; 23.3
percent) and mast and seeds (21.4 percent). Shinnery oak parts
comprised 22.5 percent of the overall diet. Olawsky (1987, pp. 24, 30)
also examined lesser prairie-chicken diets during the summer season
(May, June, and July); however, he also compared diets between areas
treated with tebuthiuron and untreated pastures in Texas and New
Mexico. While the diets in treated and untreated areas were different,
the diet from the untreated area should be representative of a typical
summer diet. Total plant matter from birds collected from the untreated
areas comprised 68 to 81 percent, by volume (Olawsky 1987, pp. 30-32).
Foliage comprised 21 to 25 percent, and seeds and mast, 36 to 60
percent, of the diet from birds collected in the untreated area.
Shinnery oak acorns were the primary form of seeds and mast consumed.
Animal matter comprised 19 to 32 percent of the overall diet, and
almost all of the animal matter consisted of treehoppers and short-
horned grasshoppers (Olawsky 1987, pp. 30-32).
Several studies have reported on the fall and winter diets of
lesser prairie-chickens. Davis et al. (1979, pp. 70-80), Smith (1979,
pp. 24-32), and Riley et al.
[[Page 20003]]
(1993, pp. 186-189) all reported on lesser prairie-chicken food habits
from southeastern New Mexico (Chaves County), where the birds had no
access to grain fields (Smith 1979, p. 31). They generally found that
fall (October to early December) and winter (January and February)
diets generally consist of a mixture of seeds, vegetative material, and
insects.
The fall diet differed between years primarily due to reduced
availability of shinnery oak acorns (Smith 1979, p. 25). Reduced
precipitation in the fall of 1976 was thought to have influenced acorn
production in 1977 (Riley et al. 1993, pp. 188). When acorns were
available, shinnery oak acorns comprised almost 62 percent, by volume,
of the diet but less than 17 percent during a year when the acorn crop
failed (Smith 1979, p. 26). On average, total mast and seeds consumed
was 43 percent, vegetative material was 39 percent, and animal matter
was 18 percent by volume of the fall diet (Davis et al. 1979, p. 76).
Over 81 percent of the animal matter consumed was short-horned
grasshoppers (Davis et al. 1979, p. 76).
Crawford (1974, pp. 19-20, 35-36) and Crawford and Bolen (1976c,
pp. 142-144) reported on the fall (mid-October) diet of lesser prairie-
chickens in west Texas over a 3-year period. Twenty-three species of
plants were identified from the crops over the course of the study.
Plant matter accounted for 90 percent of the food present by weight and
81 percent by volume. Grain sorghum also was prevalent, comprising 63
percent by weight and 43 percent by volume of total diet. Alhborn
(1980, pp. 53-58) also documented use of grain sorghum during the fall
and winter in eastern New Mexico. The remainder of the diet (10 percent
by weight and 19 percent by volume) was animal matter (insects only).
Over 62 percent, by volume, of the animal matter was composed of short-
horned grasshoppers. Other insects that were important in the diet
included darkling beetles, walking sticks (Phasmidae), and wingless
long-horned grasshoppers (Gryllacrididae). During the fall and winter
in eastern New Mexico, Alhborn (1980, pp. 53-58) reported that
vegetative material from shinnery oak constituted 21 percent of the
total diet.
Similarly, Doerr (1980, p. 32) reported on the lesser prairie-
chickens from west Texas in the fall (October). The diet largely
comprised animal matter (86 percent by volume) with short-horned
grasshoppers contributing 81 percent by volume of the total diet.
Stinkbugs also were prevalent in the diet. Foliage was the least
important component, consisting of only 2.5 percent by volume. Seeds
and acorns comprised 11 percent of the diet and consisted entirely of
shinnery oak acorns and seeds of Linum rigidum (stiffstem flax).
Shinnery oak acorns (69 percent) and annual buckwheat (14 percent)
were the primary components of the winter (January and February) diet
of lesser prairie-chickens in southeastern New Mexico (Riley et al.
1993, p. 188). Heavy selection for acorns in winter was attributed to
need for a high energy source to help sustain body temperature in cold
weather (Smith 1979, p. 28). Vegetative matter was about 26 percent of
overall diet, by volume, with 5 percent of the diet consisting of
animal matter, almost entirely comprising ground beetles (Carabidae)
(Davis et al. 1979, p. 78).
In contrast to the above studies, Jones (1963b, p. 20) and Doerr
(1980, p. 8) examined food items present in the droppings rather than
from the crops. Although this approach is valid, differential digestion
of the food items likely overemphasizes the importance of indigestible
items and underrepresents occurrence of foods that are highly
digestible (Jones 1963b, p. 21; Doerr 1980, pp. 27, 33). Jones' study
site was located in the sand sagebrush dominated grasslands in the more
northern portion of the historical range where shinnery oak was
unavailable. However, Doerr's study site was located in the shinnery
oak dominated grasslands of the southwest Texas panhandle.
In the winter (December through February), where Rhus trilobata
(skunkbush sumac) was present, Jones (1963b, pp. 30, 34) found lesser
prairie-chickens primarily used sumac buds and foliage of sumac, sand
sagebrush, and Gutierrezia sarothrae (broom snakeweed), particularly
when snow was on the ground. Small annual plants present in the diet
were Vulpia (Festuca) octoflora (sixweeks fescue), annual buckwheat,
and Evax prolifera (big-headed evax; bigheaded pygmycudweed) (Jones
1963b, p. 30). Grain sorghum wasn't used to any appreciable extent,
particularly when skunkbush sumac was present, but was eaten when
available. Relatively few insects were available during the winter
period. However, beetles were consumed throughout the winter season and
grasshoppers were important in December. Doerr (1980, p. 28) found
grasshoppers, crickets, ants, and wasps were the most commonly observed
insects in the winter diet. Foliage from sand sagebrush and Cryptantha
cinerea (James' cryptantha) was prevalent, but shinnery oak acorns were
by far the most significant plant component detected in the winter
diet.
In the spring (March through May), lesser prairie-chickens used
seeds and foliage of early spring annuals such as Viola bicolor (johnny
jumpup) and Silene antirrhina (sleepy catchfly) (Jones 1963b, p. 49).
Skunkbush sumac continued to be an important component of the diet.
Insect use increased as the spring season progressed. Doerr (1980, p.
29) also observed that grasshoppers and crickets were prevalent in the
spring diet. However, foliage and acorns of shinnery oak were more
abundant in the diet than any other food item.
In the summer (June through August), lesser prairie-chickens
continued to use sumac and other plant material, but insects dominated
the diet (Jones 1963b. pp. 64-65). Grasshoppers were the principal item
found in the diet, but beetles were particularly favored in shrubby
habitats. Similarly, Doerr (1980, p. 25) found grasshoppers and
crickets were the most important component of the summer diet followed
in importance by beetles. Jones (1963b, pp. 64-65) reported fruits from
skunkbush sumac to be the most favored plant material in the diet.
Doerr (1980, p. 25) found James cryptantha and erect dayflower were the
two most important plants in the diet in his study. Insects remained a
principal food item in the fall (September through November), at least
until November when plant foods, such as Cyperus schweinitzii
(flatsedge) and Ambrosia psilostachya (western ragweed) became more
prevalent in the diet (Jones 1963b, pp. 80-81).
Little is known regarding the specific water requirements of the
lesser prairie-chicken, but their distribution does not appear to be
strongly influenced by the presence of surface water. Total annual
precipitation across the range of the lesser prairie-chicken varies, on
average, from roughly 63 cm (25 in) in the eastern portions of the
historical range to as little as 25 cm (10 in) in the western portions
of the range. Consequently, fewer sources of free-standing surface
water existed in lesser prairie-chicken historical range prior to
settlement than currently exist. Lesser prairie-chickens likely rely on
food sources and consumption of dew to satisfy their metabolic moisture
requirement (Snyder 1967, p. 123; Hagen and Giesen 2005, unpaginated;
Bidwell et al. 2002, p. 6) but will use surface water when it is
available. Boal and Pirius (2012, p. 6) observed that 99.9 percent of
lesser prairie-chicken locations they recorded in west Texas were
within 3.2 km (2.0 mi) of an available water source and may be
[[Page 20004]]
indicative of the importance of surface water sources. Grisham et al.
(2013, p. 7) believed that use of available standing water may be
particularly important for egg development during drought conditions
and its importance may be overlooked. Because much of the historically
occupied range is now used for domestic livestock production, numerous
artificial sources of surface water, such as stock ponds and stock
tanks, have been developed throughout the region. Several studies have
documented use of these water sources by lesser prairie-chickens during
the spring, late summer, and fall seasons (Copelin 1963, p. 20; Jones
1964, p. 70; Crawford and Bolen 1973, pp. 471-472; Crawford 1974, p.
41; Sell 1979, p. 31), and they may be particularly important during
periods of drought (Crawford and Bolen 1973, p. 472; Crawford 1974, p.
41). Hoffman (1963, p. 732) supported development of supplemental water
sources (i.e., guzzlers) as a potential habitat improvement tool.
Others, such as Davis et al. (1979, pp. 127-128) and Applegate and
Riley (1998, p. 15) cautioned that creating additional surface water
sources will influence grazing pressure and possibly contribute to
degradation of habitat conditions for lesser prairie-chickens.
Rosenstock et al. (1999, p. 306) reported that some predators,
particularly raptors, benefit from the presence of surface water
sources developed for wildlife in arid environments. Additionally, some
livestock watering facilities may create other hazardous conditions
(e.g., drowning; Sell 1979, p. 30), but the frequency of these
incidents is unknown.
Lesser prairie-chickens have a relatively short lifespan and high
annual mortality. Campbell (1972, p. 694) estimated a 5-year maximum
lifespan, although an individual nearly 7 years old has been documented
in the wild by the Sutton Avian Research Center (Sutton Center) (Wolfe
2010, pers. comm.). Average natural lifespan or generation time was
calculated, based on work by Farner (1955, entire), to be 1.95 years
(Van Pelt et al. 2013, p. 130). Pruett et al. (2011, p. 1209) also
estimated generation time in lesser prairie-chickens and found
generation times were slightly lower in Oklahoma (1.92 years) than in
New Mexico (2.66 years). Lesser prairie-chickens and other galliform
birds appear to have particularly short lifespans for their size
(Lindstedt and Calder 1976, p. 91).
Differences in survival may be associated with sex, weather,
harvest (where allowed), age, and habitat quality. Campbell (1972, p.
689), using 9 years of band recovery data from New Mexico, estimated
annual mortality for males to be 65 percent. Hagen et al. (2005, p. 82)
specifically examined survival in male lesser prairie-chickens in
Kansas and found apparent survival varied by year and declined with
age. Annual mortality was estimated to be 55 percent (Hagen et al.
2005, p. 83). Survival rates for lesser prairie-chickens in
northeastern Texas were lower for both sexes during the breeding season
than during the non-breeding season (Jones 2009, p. 16). Estimated
survival was 52 percent. Lesser prairie-chickens in New Mexico and
Oklahoma also had higher mortality during the breeding season than at
other times of the year (Patten et al. 2005b, p. 240; Wolfe et al.
2007). Male survival may be lower during the breeding season due to
increased predation or costs associated with territorial defense while
lekking (Hagen et al. 2005, p. 83). In female lesser prairie-chickens,
Hagen et al. (2007, p. 522) estimated that annual mortality in two
remnant patches of native sand sagebrush prairie near Garden City,
Finney County, Kansas was about 50 percent at a study site southwest of
Garden City and about 65 percent at a study site southeast of Garden
City. Female survival may be lower during the breeding season due to
the costs associated with reproduction (see both Hagen et al. 2005 and
2007.). Grisham (2012, pp. 19-20) found that female survival (at least
71 percent) was higher than male survival (57 percent). Observed female
survival rates were much higher than those reported elsewhere in the
literature (see Campbell 1972, Merchant 1982, and Hagen et al. 2007)
but may have been a function of the statistical test used in the
analysis (Grisham 2012, pp. 21-22). Principally, the study by Grisham
(2012, entire) demonstrated lesser prairie-chickens may have high
survival during the breeding season in shinnery oak habitats.
Adult annual survival in Texas apparently varied by habitat type.
In sand sagebrush habitat, survival was estimated to be 0.52, whereas
survival was only 0.31 in shinnery oak habitat (Lyons et al. 2009, p.
93). For both areas, survival was about 4 percent lower during the
breeding season than during the nonbreeding period (Lyons et al. 2009,
p. 93). Hagen et al. (2007, p. 522) also reported lower survival during
the reproductive season (31 percent mortality) compared to the
nonbreeding season (23 percent mortality) in Kansas. In contrast with
Lyons et al. (2009), survival times did not differ between sand
sagebrush habitats in Oklahoma and shinnery oak habitats in New Mexico
(Patten et al. 2005a, p. 1274). Birds occupying sand shinnery sites
with greater than 20 percent shrub cover survived longer than those in
areas with less dense shrub cover (Patten et al. 2005a, p. 1275). Areas
with greater than 20 percent shrub cover likely provided a more
suitable microclimate through enhanced thermal protection than areas
with less shrub cover.
Availability of food and cover are key factors that affect chick
and juvenile survival. Habitats used by lesser prairie-chicken broods
had greater biomass of invertebrates and forbs than areas not
frequented by broods in Kansas (Hagen et al. 2005, p. 1087); Jamison et
al. 2002, p. 524). Chick survival averaged only about 25 percent during
the first 35 days following hatching (Hagen 2003, p. 135). Survival for
chicks between 35 days of age and the following spring was estimated to
be 53.9 percent in southwestern Kansas (Hagen et al. 2009, p. 1326).
Jamison (2000, p. 57) estimated survival of chicks from hatching to
early autumn (60 days post-hatching), using late summer brood sizes
provided in several early studies, to be 27 percent in Kansas and 43-65
percent in Oklahoma. These values were considerably higher than the 19
percent Jamison observed in his study and may reflect an inability in
the earlier studies to account for the complete loss of broods and
inclusion of mixed broods (combined broods from several females) when
estimating brood size (Jamison 2000, p. 57). Pitman et al. (2006b, p.
677) estimated survival of chicks from hatching to 60-days post-
hatching to be 17.7 percent. Recruitment was characterized as low with
survival of juvenile birds from hatching to the start of the first
breeding season the following year estimated to be only 12 percent
(Pitman et al. 2006b, pp. 678-680), which may be a significant limiting
factor in southwestern Kansas. However, the authors cautioned that
these estimates might not be indicative of survival estimates in other
areas due to low habitat quality, specifically poor distribution of
nesting and brood-rearing habitats within the study area (Pitman et al.
2006b, p. 680).
Conservation Genetics
Persistence of wild populations is usually influenced more by
ecological rather than by genetic effects; however, as population size
declines, genetic factors often become increasingly important (Lande
1995, p. 318). Considering that lesser prairie-chickens have one of the
smallest population sizes and most restricted geographic distributions
of any native North American grouse (Hagen and Giesen 2005,
unpaginated), an understanding of
[[Page 20005]]
relevant genetic factors can be valuable when implementing conservation
efforts, particularly where translocation and other forms of
reintroduction may be considered. Van Den Bussche et al. (2003, entire)
examined genetic variation within the lesser prairie-chicken using
mitochondrial deoxyribonucleic acid (DNA) (mtDNA, maternally-inherited
DNA located in cellular organelles called mitochondria) and nuclear
microsatellite (short, tandem repeating sequences of DNA nucleotide
base pairs) data from 20 lek sites in Oklahoma and New Mexico. They
found that these lesser prairie-chicken populations maintain high
levels of genetic variation and genetic diversity did not differ
between leks in Oklahoma and New Mexico (Van Den Bussche et al. 2003,
p. 680). Historical gene flow between birds in Oklahoma and New Mexico
was considered to be low, leading to some genetic differentiation
between the two populations (Van Den Bussche et al. 2003, p. 681).
These findings are not unexpected, considering these populations are
fragmented and separated by at least 300 km (200 mi). Bouzat and
Johnson (2004, entire) examined genetic structure between four closely
spaced leks within a lesser prairie-chicken population in New Mexico.
They detected increased inbreeding within these closely spaced leks,
leading to an increase in homozygosity (having the same inherited
alleles (gene form), rather than different alleles at a particular gene
location on both homologous chromosomes (threadlike linear strands of
DNA and associated proteins in the cell nucleus that carries the genes
and functions in the transmission of hereditary information)) within
these leks (Bouzat and Johnson 2004, p. 503). Although no deleterious
effects to demographic rates have yet been documented in New Mexico
populations, a loss of genetic diversity and inbreeding can lead to a
reduction in reproductive fitness in prairie grouse (Bouzat et al.
1998a, p. 841; Bouzat et al. 1998b, p. 4).
Hagen et al. (2010, entire) examined variability in mtDNA of lesser
prairie-chickens across their range, with the exception of Texas. They
observed low levels of population differentiation (p. 33) with
relatively high levels of genetic diversity in most populations (pp.
33-34). Their data suggest that gene flow continues to occur over most
of the occupied range, with significant differences between New Mexico
populations and the rest of the studied range. As previously indicated
the New Mexico population is separated by considerable distance from
the remainder of the studied range. The population in New Mexico was
significantly different from the others examined and lacked gene flow
with the remainder of the populations in Colorado, Kansas and Oklahoma
(Hagen et al. 2010, p. 34). This suggests that lesser prairie-chickens
in New Mexico are isolated from populations in Colorado, Kansas and
Oklahoma.
Complementary work by Corman (2011, entire) examined genetic
diversity in lesser prairie-chicken populations in Texas. In examining
population differentiation, the population in Deaf Smith County was not
significantly different from the remainder of the populations in the
southwestern panhandle and eastern New Mexico nor was this population
significantly different from the population in Lipscomb, Hemphill, and
Wheeler counties (Corman 2011, p. 47). The Gray and Donley County
population and the Lipscomb, Hemphill, Wheeler population of northeast
Texas panhandle had the lowest differentiation of the four geographical
regions studied. The Deaf Smith County and the Gray and Donley County
populations had the greatest differentiation even though they were
intermediate by distance between the regions. The southwest Texas
panhandle population revealed little differentiation with the New
Mexico population (Corman 2011, p. 48). Genetic clustering efforts
without regard to region indicated the northeast Texas populations and
the southwest Texas panhandle-New Mexico populations were the two
primary geographic clusters of lesser prairie-chickens in Texas.
Genetic clustering within these two primary geographic clusters
indicated that additional clusters were present. Within the southwest
Texas panhandle-New Mexico cluster, the population in Deaf Smith County
clustered separately from the remainder of the population in the
southwest Texas and New Mexico cluster. In the northeastern Texas
cluster, the Gray and Donley County population clustered separately
from the remainder of the populations in Lipscomb, Hemphill, and
Wheeler counties (Corman 2011, p. 49). The two primary population
clusters are separated by a geographical distance of about 160 to 250
km (99 to 155 mi). Overall genetic diversity in Texas has remained
relatively high despite observed population declines since 1900 (Corman
2011, p. 112). Genetic diversity tends to be higher in northeastern
Texas Panhandle relative to the rest of Texas and New Mexico (Corman
2011, p. 112). This population likely maintains gene flow with
populations in adjacent portions of Oklahoma. The population cluster
that persists in the Deaf Smith County region had much lower diversity
than other locations in Texas. Diversity estimates obtained by Corman
(2011, p. 113) were comparable with those provided by Hagen et al.
(2010, entire). Genetic diversity is particularly important to
maintaining reproductive fitness. Gregory (2011, p. 18) observed that
for greater prairie-chickens, the most genetically diverse males were
more likely to live longer than less diverse males and were more likely
to be the most successful male on the lek.
Corman (2011, p. 142) estimates that the lesser prairie-chicken
effective population size is about 560 to 610 individuals are required
for the southwestern Texas Panhandle and New Mexico populations and
about 120 to 260 individuals for the northeast Texas Panhandle region.
Consistent with previous studies, the southwest Texas/eastern New
Mexico lesser prairie-chicken population is isolated from the remainder
of the range (a condition which has been in place for perhaps at least
6-7 decades) and exhibits effects from genetic drift as indicated by
lower genetic variability (Corman 2011, p. 116). Based on estimates of
the effective population size, the southwest Texas/eastern New Mexico
population may be large enough to maintain evolutionary potential
(ability to adapt to changing conditions over time) if there were no
further population declines or changes in habitat conditions (Corman
2011, p. 120). However, the lesser prairie-chicken populations in the
northeast Texas panhandle do not appear to be large enough to maintain
evolutionary potential without stabilizing populations and continued
connectivity to populations in Oklahoma (Corman 2011, p. 120).
Pruett et al. (2011, entire) examined effective population size in
lesser prairie-chickens from New Mexico and Oklahoma. Effective
population size is useful for determining extinction risk in small
populations and is a measure of the actual number of breeding
individuals in a population. The effective size of a population is
often much less than the actual number of individuals within the same
population. It is defined as the size of an idealized population of
breeding adults that would experience the same rate of (1) loss of
heterozygosity (the amount and number of different genes within
individuals in a population), (2) change in the average inbreeding
coefficient (a
[[Page 20006]]
calculation of the amount of breeding by closely related individuals),
or (3) change in variance in allele (one member of a pair or series of
genes occupying a specific position in a specific chromosome) frequency
through genetic drift (the fluctuation in gene frequency occurring in
an isolated population) as the actual population. As the effective
population size decreases, the rate of loss of allelic diversity via
genetic drift increases, reducing adaptive potential and increasing the
risk of inbreeding depression.
Estimates of effective population size, based on the parameters for
the demographic variables they modeled, was estimated to be between 341
and 1,023 individuals in Oklahoma and between 944 and 2,375 individuals
in New Mexico (Pruett et al. (2011, p. 1209). Using genetic
information, which generally yields smaller effective population sizes,
Pruett et al. (2011, p. 1211) estimated current effective population
size in Oklahoma to be about 115 individuals and about 55 individuals
in New Mexico. This value for New Mexico is considerably smaller than
the value determined for New Mexico by Corman (560 to 610 individuals)
(2011, p. 142). However, Corman included birds from southwest Texas in
his estimates of the Texas Panhandle and New Mexico populations, which
likely contributed to the higher estimate of effective population size.
Despite these low numbers resulting from genetic analysis, based on
estimates of the effective population size, we conclude that the
southwest Texas/eastern New Mexico population may be able to maintain
evolutionary potential (ability to adapt to changing conditions over
time) if there are no further population declines or changes in habitat
conditions.
Garton (2012, entire) conducted a reconstruction analysis of lesser
prairie-chicken population abundance through time to model the likely
future of lesser prairie-chicken populations. His analysis evaluated
both rangewide populations and each of the four ecoregions where the
lesser prairie-chicken occurs. To do so, Garton (2012, p. 5) used the
effective population size values of 50 individuals for short-term (30
year) persistence and 500 for long-term (100 year) persistence and
adjusted these for count composition of sexes resulting in an estimated
effective population size of 85 birds for short-term persistence and
852 birds for long-term persistence. Using these estimated effective
population sizes, Garton (2012, p. 16-17) projected that in 30 years
the estimated rangewide carrying capacity of lesser prairie-chickens
would be about 10,000 birds and less than 1,000 birds in 100 years,
provided existing conditions did not change. Based on these numbers,
Garton (2012, p. 18, 32) concludes from the most recent data, two of
the eco-regions (sand sagebrush prairie and mixed grass/CRP) and the
rangewide species population have high to very high probabilities of
falling below quasi-extinction thresholds within 30 years. Garton
(2012, p. 18) also concludes that analysis across the long-term data
paint a more optimistic picture of the rangewide species carrying
capacity, but the fundamental pattern is still one of declining trends
that must be reversed in the long term to conserve the species.
Habitat
The preferred habitat of the lesser prairie-chicken is native
prairies composed of short- and mixed-grasses with a shrub component
dominated by Artemesia filifolia (sand sagebrush) or Quercus havardii
(shinnery oak) (hereafter described as native rangeland) (Donaldson
1969, pp. 56, 62; Taylor and Guthery 1980a, p. 6; Giesen 1998, pp. 3-
4). In more moist, less sandy soils, other small shrubs, such as plums
and sumac, become more prevalent; however, the habitat remains suitable
for lesser prairie-chickens. Small shrubs, along with tall grasses,
provide cover/concealment for nesting hens and broods and are important
for summer shade (Copelin 1963, p. 37; Donaldson 1969, pp. 44-45, 62),
winter protection, and as supplemental foods (Johnsgard 1979, p. 112).
Typically the height and structure of short-grass prairie alone does
not provide suitable cover when shrubs or taller grasses are absent.
Historically, trees and other tall, woody vegetation were largely
absent from these grassland ecosystems, except in canyons and along
water courses. Prairie landscapes supporting less than 63 percent
native rangeland appear incapable of supporting self-sustaining lesser
prairie-chicken populations (Crawford and Bolen 1976a, p. 102).
Outside of the CRP dominated grasslands in Kansas, lesser prairie-
chickens are primarily found in the sand sagebrush dominated native
rangelands of Colorado, Kansas, Oklahoma, and Texas, and in the
shinnery oak-bluestem grasslands of New Mexico, Oklahoma, and Texas.
Sand sagebrush is a 0.6- to 1.8-m (2- to 6-ft) tall shrub that occurs
in 11 States of the central and western United States (Shultz 2006, p.
508). Within the central and southern Great Plains, sand sagebrush is
often a dominant species on sandy soils and may exhibit a foliar cover
of 20 to 50 percent (Collins et al. 1987, p. 94; Vermeire 2002, p. 1).
Sand-sage shrublands have been estimated to occupy 4.8 million ha (11.8
million ac) in the central and southern Great Plains (Berg 1994, p.
99).
The shinnery oak vegetation type is endemic to the southern great
plains and is estimated to have historically covered an area of 2.3
million ha (over 5.6 million ac), although its current range has been
considerably reduced through eradication (Mayes et al. 1998, p. 1609).
The distribution of shinnery oak overlaps much of the historical lesser
prairie-chicken range in New Mexico, Oklahoma, and Texas (Peterson and
Boyd 1998, p. 2). Shinnery oak is a rhizomatous (a horizontal, usually
underground stem that often sends out roots and shoots from its nodes)
shrub that reproduces slowly and does not invade previously unoccupied
areas (Dhillion et al. 1994, p. 52). Mayes et al. (1998, p. 1611)
documented that a single rhizomatous shinnery oak can occupy an area
exceeding 7,000 square meters (sq m) (75,300 square feet (sq ft)).
Shinnery oak in some areas multiplies by slow rhizomatous spread and
eventual fracturing of underground stems from the original plant. In
this way, single clones have been documented to occupy up to 81 ha (200
ac) over an estimated timeframe of 13,000 years (Cook 1985, p. 264;
Anonymous 1997, p. 483), making shinnery oak possibly the largest and
longest-lived plant species in the world.
Within the historical range of the species, the USDA's CRP,
administered by the FSA, has promoted the establishment and
conservation of certain grassland habitats. Originally funded as a
mechanism to reduce erosion from highly erodible soils, the program has
since become a means to at least temporarily retire any environmentally
sensitive cropland from production and establish vegetative cover on
that land. Initially, many types of grasses were approved for use as
permanent vegetative cover, including several that are nonnative. The
use of native grasses has become more prevalent over time. In Kansas in
particular, much of the vegetative cover established through the CRP
within the historical range of the lesser prairie-chicken was a mix of
native warm-season grasses such as Schizachyrium scoparium (little
bluestem), Bouteloua curtipendula (sideoats grama), and Panicum
virgatum (switchgrass) (Rodgers and Hoffman 2005, p. 120). These
grasses are important components of lesser prairie-chicken habitat and
have led to reoccupation of large areas of the historical range in
western Kansas
[[Page 20007]]
by lesser prairie-chickens, particularly north of the Arkansas River.
In other areas, nonnative grasses were used that displaced the
native, warm season grasses, providing little, if any, habitat value
for the lesser prairie-chicken. Exotic old world bluestems and
Eragrostis curvula (weeping lovegrass) were extensively seeded in CRP
tracts in Texas, New Mexico, and Oklahoma (Haufler et al. 2012, p. 17;
Hickman and Elmore 2009, p. 54). For example, about 70 to 80 percent of
the original CRP seedings in eastern New Mexico consisted of dense,
single-species stands of weeping lovegrass, Bothriochloa bladhii
(Caucasian bluestem), or B. ischaemum (yellow bluestem) (Rodgers and
Hoffman 2005, p. 122). Monocultures of old world bluestem and other
exotic grasses contribute very little to lesser prairie-chicken
conservation as they provide poor-quality nesting and brood rearing
habitat. Toole (2005, p. 21) reported that the abundance of
invertebrates, which are used as food for both adults and young, was
over 32 times lower in weeping lovegrass CRP fields than in pastures
containing native warm season grasses. However, as these nonnative CRP
grasslands have matured over the last two decades, some species of
native grasses and shrubs are beginning to reestablish within these
fields. The lesser prairie-chicken will occasionally use these older
stands of exotic grasses for roosting and nesting (Rodgers and Hoffman
2005, p. 122), but such fields often continue to provide limited
habitat value for lesser prairie-chickens. In contrast, where CRP lands
support native, warm season grasses having the suitable vegetative
structure and species composition required by lesser prairie-chickens,
these fields can provide high quality habitat. See section on
``Conservation Reserve Program (CRP)'' for more information on CRP.
Leks are characterized by areas of sparse or low vegetation (10 cm
(4 in) or less) cite for height see Plan) and are generally located on
elevated features, such as ridges or grassy knolls (Giesen 1998, p. 4).
Vegetative cover characteristics, primarily height and density, may
have a greater influence on lek establishment than elevation (Giesen
1998, p. 4). Copelin (1963, p. 26) observed display grounds within
short grass meadows of valleys where sand sagebrush was tall and dense
on the adjacent ridges. Early spring fires also encouraged lek
establishment when vegetation likely was too high (0.6 to 1.0 m (2.0 to
3.3 ft)) to facilitate displays (Cannon and Knopf 1979, pp. 44-45).
Several authors, as discussed in Giesen (1998, p. 4), observed that
roads, oil and gas pads, and similar forms of human disturbance can
create habitat conditions that may encourage the establishment of
artificial lek sites (as opposed to those in native grasslands). Site
fidelity also may play a role in continued use of certain areas as lek
sites, despite some forms of human disturbance. However, Taylor (1979,
p. 707) emphasized that human disturbance, which is often associated
with these artificial lek sites, is detrimental during the breeding
season and did not encourage construction of potential lek sites in or
near areas subject to human disturbance. Leks are typically located
near areas that provide good nesting habitat. Giesen (1998, p. 9)
reported that hens usually nest and rear broods within 3.4 km (2.1 mi)
of leks and may return to nest in areas of previously successful nests
(Riley 1978, p. 36). Giesen (1994a, pp. 97-98) and Hagen and Giesen
(2005, unpaginated) also reported that hens often nest closer to a lek
other than the one on which they mated. Adequate nesting and brood
rearing habitats are crucial to population growth as they influence
nest success and brood survival.
Typical nesting habitat can be generally described as native
rangeland, although vegetation structure, such as the height and
density of forbs and residual grasses, is frequently greater at nesting
locations than on adjacent rangeland (Giesen 1998, p. 9). Adequate
herbaceous cover, including residual cover from the previous growing
season, is an important factor influencing nest success, primarily by
providing concealment of the nest (Suminski 1977, p. 32; Riley 1978, p.
36; Riley et al. 1992, p. 386; Giesen 1998, p. 9). Concealment of the
nest is important as successful nests are often associated with greater
heights and cover of shrubs and perennial grasses than are unsuccessful
nests. Nests are often located on north and northeast facing slopes as
protection from direct sunlight and the prevailing southwest winds
(Giesen 1998, p. 9).
Giesen (1998, p. 9) reports that habitat used by young is similar
to that of adults, but good brood rearing habitat will have less grass
cover and higher amounts of forb cover than nesting habitat (Hagen et
al. 2013, p. 4). Dense grass cover impedes movements of the chicks
(Pitman et al. 2009, p. 680). Forbs are important for the insects they
produce which in turn influences body mass of the chicks (Pitman et al.
2006b, p. 680). Considering the limited mobility of broods--daily
movement of the broods is usually 300 m (984 ft) or less (Candelaria
1979, p. 25)--optimum brood rearing habitat is typically found close to
nesting areas. In Kansas, habitats used by broods had greater total
biomass of invertebrates and forb cover than areas not frequented by
broods, emphasizing the importance of forbs in providing the
invertebrate populations used by young lesser prairie-chickens (Jamison
et al. 2002, pp. 520, 524). Grisham (2012, p. 153) observed that brood
survival through 14 days post-hatching was the primary factor limiting
population growth of lesser prairie-chickens and that a lack of forbs
necessary to support abundant insects was implicated as a primary
factor influencing brood survival. After the broods break up, the
juveniles form mixed flocks with adult birds (Giesen 1998, p. 9), and
juvenile habitat use is similar to that of adult birds.
The rangewide plan provides a detailed characterization of lesser
prairie-chicken preferred nesting and brood rearing habitat in native
rangelands with a shinnery oak or sand sagebrush shrub component and in
areas dominated by CRP fields where native shrubs are often absent (Van
Pelt et al. 2013, pp 75-76). Additionally, Hagen et al. (2013, entire)
conducted a meta-analysis (analysis of information from multiple
studies) of lesser prairie chicken nesting and brood rearing habitat
within both sand sagebrush and shinnery oak dominated vegetative
communities and the mixed grass community. They reported average values
for 10 different parameters and used these summarized values derived
from 14 different studies (Hagen et al. 2013, p. 755). In general, they
reported that lesser prairie-chicken nesting habitat in sand sagebrush
regions have at least 60 percent canopy cover of forbs, and shrubs and
grasses that are at least 25 cm (9.8 in) tall in western portions of
the range to over 40 cm (15.7 in) tall in the eastern portion of the
range.
Habitat use at finer scales indicates that lesser prairie-chickens
throughout the year consistently occupied sites with greater cover than
what was available across the landscape (Larrson et al. 2013, pp. 138,
140). Microhabitats selected were based on presence of specific species
of grasses and forbs and specific vegetative structure (Larrson et al.
2013, p. 138-139). The researchers inferred that predation and
temperature influenced habitat selection by lesser prairie-chickens,
with birds using more open areas during periods with cooler
temperatures and more dense vegetation during periods with hotter
temperatures (Larrson et al. 2013, p. 141). However, there may be a
tradeoff between sites that are thermally favorable and sites that
minimize the risk of predation.
[[Page 20008]]
Maintaining a diverse native plant community with a suite of structural
composition (e.g., height and density) that meets all of the lesser
prairie-chicken cover requirements for breeding, nesting and brood
rearing may help compensate for tradeoffs between microclimate
preferences and predator avoidance.
Giesen (1998, p. 4) reports that fall and winter habitat
requirements are similar to those used during the nesting and brood
rearing seasons, with the exception that cultivated grain fields are
used more heavily during these periods than during the breeding season.
Considering lesser prairie-chickens tend to spend most of their daily
and seasonal activity near (within 4.8 km (3.0 mi)) the display grounds
even during the non-breeding season (Giesen 1994, p. 97; Riley et al.
1994, p. 185; Woodward et al. 2001, p. 263), similarity in habitat use
across seasons is not surprising. Boal and Pirius (2012, p. 6) observed
that slightly more than 97 percent of the radio-marked birds they
followed were relocated within 3.2 km (2 mi) of the breeding ground on
which they were captured and just under 97 percent of the marked birds
were located within 3.2 km (2 mi) of a known lek. Similarly Kukal
(2010, p. 19) reported almost 98 percent of male lesser prairie-
chickens were located within 5 km (3 mi) of the lek on which they were
captured and 98 percent were within 2.3 km (1.4 mi) of a known lek.
Observations for females were very similar. Almost 98 percent of
females were located within 3.8 km (2.4 mi) of the lek on which they
were captured and roughly 98 percent were within 2.4 km (1.5 mi) from a
known lek (Kukal 2010, pp. 19-20).
There is considerable overlap in lesser prairie-chicken habitat
requirements, with the lek being the common focal point for most
activities. A mixture of lekking, nesting, brood rearing, and wintering
habitat, all in close proximity to the other, provides optimum habitat
conditions needed to support lesser prairie-chickens. Considering that
nest success and brood survival are the most critical factors
influencing population viability (Pitman et al. 2006b, p. 679; Hagen et
al. 2009, pp. 1329-1330; Grisham 2012, p. 153), Hagen et al. (2013, p.
750), a habitat mosaic consisting of approximately one-third brood
rearing habitat and two-thirds nesting habitat are key to conservation
and management of the lesser prairie-chicken (Hagen et al. 2013, p.
756).
Reported home ranges, seasonal movement patterns, and dispersal
distances of lesser prairie-chickens, as previously discussed, are
indicative of their requirement for large blocks of interconnected,
ecologically diverse native grassland. Taylor and Guthery (1980a, p.
11) used lesser prairie-chicken movements in west Texas to estimate the
area needed to meet the minimum requirements of a lek population. A
contiguous area of suitable habitat encompassing at least 32 sq km (12
sq mi or 7,900 ac) would support about 90 percent of the annual
activity associated with a given lek and an area of 72 sq km (28 sq mi
or 17,791 ac) would include all of the annual activity associated with
a lek except for some movements of juveniles (Taylor and Guthery
(1980a, p. 11). Bidwell et al. (2002, p. 3) speculated that at least
101.2 sq km (39 sq mi or 25,000 ac) of contiguous high-quality habitat
may be needed to maintain a sustainable population of lesser prairie-
chickens. Because lesser prairie-chickens typically nest and rear their
broods in proximity to a lek other than the one used for mating (Giesen
1998, p. 9), a complex of two or more leks is likely the very minimum
required to sustain a viable lesser prairie-chicken population. Hagen
et al. (2004, p. 76) recommended that lesser prairie-chicken management
areas be at least 4,096 sq km (1,581 sq mi or 1,012,140 ac) in size.
Management areas of this size would incorporate the longest-known
movements of individual birds and be large enough to maintain healthy
lesser prairie-chicken populations despite the presence of potentially
large areas of unsuitable habitat.
Historical Range and Distribution
Prior to description by Ridgeway in 1885, most observers did not
differentiate between the lesser and greater prairie-chicken.
Consequently, estimating historical abundance and occupied range is
difficult. Historically, the lesser prairie-chicken is known to have
occupied native rangeland in portions of southeastern Colorado (Giesen
1994b, pp. 175-182), southwestern Kansas (Baker 1953, p. 9; Schwilling
1955, p. 10), western Oklahoma (Duck and Fletcher 1944, p. 68), the
Texas panhandle (Henika 1940, p. 15; Oberholser 1974, p. 268), and
eastern New Mexico (Ligon 1927, pp. 123-127).
Lesser prairie-chickens also have been documented from Nebraska,
based on at least four specimens known to have been collected near
Danbury in Red Willow County during the 1920s (Sharpe 1968, p. 50).
Sharpe (1968, pp. 51, 174) considered the occurrence of lesser prairie-
chickens in Nebraska to be the result of a short-lived range expansion
facilitated by settlement and cultivation of grain crops. Lesser
prairie-chickens are not currently believed to occur in Nebraska.
Sharpe did not report any confirmed observations since the 1920s
(Sharpe 1968, entire), and no sightings have been documented despite
searches over the last 5 years in southwestern Nebraska (Walker 2011).
Therefore, Nebraska is generally considered outside the historical
range of the species.
Based on a single source, Crawford (1974, p. 4) reported that the
lesser prairie-chicken was successfully introduced to the island of
Niihau in the State of Hawaii. Prairie-chickens were known to have been
released on Niihau, a privately owned island, in 1934 (Fisher 1951, p.
37), but the taxonomic identity of those birds has not ever been
confirmed. Schwartz and Schwartz (1949, p. 120) believed that these
birds were indeed lesser prairie-chickens. Fisher and members of his
expedition did observe at least eight individual prairie-chickens
during a visit to Niihau in 1947, but no specimens were collected due
to their scarcity and the landowner's requests (Fisher 1951, pp. 33-34,
37). Consequently, the specific identity of these birds could not be
confirmed, and their current status on the island remains unknown
(Pratt et al. 1987, p. 324; Pyle and Pyle 2009, p. 5). Similarly,
Jeschke and Strayer (2008, p. 127) indicate that both lesser and
greater prairie-chickens were introduced to parts of Europe, but both
species failed to become established there. We do not believe that
either greater or lesser prairie-chickens still persist in Hawaii or
Europe, and we did not receive any comments during the comment periods
that confirmed their continued existence in either location.
Johnsgard (2002, p. 32) estimated the maximum historical range of
the lesser prairie-chicken to have encompassed between 260,000 and
388,500 sq km (100,000 to 150,000 sq mi), with about two-thirds of the
historical range occurring in Texas. Taylor and Guthery (1980a, p. 1,
based on Aldrich 1963, p. 537) estimated that, by the 1880s, the area
occupied by lesser prairie-chicken was about 358,000 sq km (138,225 sq
mi), and, by 1969, they estimated the occupied range had declined to
roughly 125,000 sq km (48,263 sq mi) due to widespread conversion of
native prairie to cultivated cropland. Taylor and Guthery (1980a, p. 4)
estimated that, by 1980, the occupied range encompassed only 27,300 sq
km (10,541 sq mi), representing a 90 to 93 percent reduction in
occupied range since pre-European settlement and a 92 percent reduction
in the occupied range since the 1880s.
[[Page 20009]]
In 2007, cooperative mapping efforts by species experts from the
Colorado Parks and Wildlife (CPW) (formerly Colorado Division of
Wildlife), Kansas Department of Wildlife, Parks and Tourism (KDWPT)
(formerly Kansas Department of Wildlife and Parks), New Mexico
Department of Game and Fish (NMDGF), Oklahoma Department of Wildlife
Conservation (ODWC), and Texas Parks and Wildlife Department (TPWD), in
cooperation with the Playa Lakes Joint Venture, reestimated the maximum
historical and occupied ranges. They determined the maximum occupied
range, prior to European settlement, to have been approximately 456,087
sq km (176,096 sq mi) (Playa Lakes Joint Venture 2007, p. 1). The
approximate historical range, by State, based on this cooperative
mapping effort is the following: 21,911 sq km (8,460 sq mi) in
Colorado; 76,757 sq km (29,636 sq mi) in Kansas; 52,571 sq km (20,298
sq mi) in New Mexico; 68,452 sq km (26,430 sq mi) in Oklahoma; and
236,396 sq km (91,273 sq mi) in Texas. Since 2007, the CPW slightly
expanded the historical range in Colorado, based on new information.
The total maximum historically occupied range, based on this
adjustment, is now estimated to be about 466,998 sq km (180,309 sq mi)
(Table 1.).
Table 1--Estimated Historical and Current Occupied Lesser Prairie-Chicken Range by State
----------------------------------------------------------------------------------------------------------------
Extent
State Historical range Current range ---------------------------------
Historical Current
----------------------------------------------------------------------------------------------------------------
Colorado............. 6 counties................. 4 counties................ 32,821.1 sq km 4,456.4 sq km
(12,672.3 sq (1,720.6 sq
mi). mi).
Kansas............... 38 counties................ 35 counties............... 76,757.4 sq km 34,479.6 sq km
(29,636.2 sq (13,312.6 sq
mi). mi).
New Mexico........... 12 counties................ 7 counties................ 52,571.2 sq km 8,570.1 sq km
(20,297.9 sq (3,308.9 sq
mi). mi).
Oklahoma............. 22 counties................ 9 counties................ 68,452.1 sq km 10,969.1 sq km
(26,429.5 sq (4,235.2 sq
mi). mi).
Texas................ 34 counties (1940s-50s).... 21 counties*.............. 236,396.2 sq km 12,126.5 sq km
(91,273.1 sq (4,682.1 sq
mi). mi).
------------------------------------------------------------------------------------------
TOTAL............ 107 counties............... 76 counties............... 466,998.0 sq km 70,601.7 sq km
(180,308.9 sq (27,259.5 sq
mi). mi).
----------------------------------------------------------------------------------------------------------------
* Timmer (2012, p. 36) observed lesser prairie-chickens in only 12 counties.
Current Range and Distribution
The lesser prairie-chicken still occurs within the States of
Colorado, Kansas, New Mexico, Oklahoma, and Texas (Giesen 1998, p. 3).
During the 2007 mapping effort (Playa Lakes Joint Venture 2007, p. 1;
Davis et al. 2008, p 19), the State conservation agencies estimated the
current occupied range encompassed 65,012 sq km (25,101 sq mi). The
approximate occupied range, by State, based on this cooperative mapping
effort was 4,216 sq km (1,628 sq mi) in Colorado; 29,130 sq km (11,247
sq mi) in Kansas; 8,570 sq km (3,309 sq mi) in New Mexico; 10,969 sq km
(4,235 sq mi) in Oklahoma; and 12,126 sq km (4,682 sq mi) in Texas.
About 95 percent of the currently estimated occupied range occurs on
privately owned land, as determined using the Protected Areas Database
of the United States hosted by the U.S. Geological Survey Gap Analysis
Program. This database represents public land ownership and
conservation lands, including voluntarily provided privately protected
areas, and the extent of private ownership can be determined by
subtracting the amount of public lands from the total land base
encompassed by the occupied range.
Since 2007, the occupied and historical range in Colorado and the
occupied range in Kansas have been adjusted to reflect new information.
The currently occupied range in Colorado is now estimated to be 4,456
sq km (1,721 sq mi), and, in Kansas, the lesser prairie-chicken is now
thought to occupy about 34,480 sq km (13,313 sq mi). In Colorado, this
adjustment is the result of survey efforts that recommended the
addition of 240 sq km (93 sq mi) of suitable habitat in the occupied
range. In Kansas, the adjustment was due to expansion of lesser
prairie-chicken populations in Ellis, Graham, Sheridan, and Trego
Counties. The total estimated occupied range is now believed to
encompass 70,602 sq km (27,259 sq mi) (Table 1). The currently occupied
range now represents roughly 16 percent of the revised historical
range. This value is a close approximation because a small portion of
the expanded range in Kansas lies outside the estimated maximum
historical range and was not included in this analysis. Considering
there are historical records from Nebraska, the maximum historical
range currently in use is likely smaller than the maximum that would
exist if the temporarily occupied range in Nebraska was included in the
analysis.
Many of the ongoing conservation efforts, including the rangewide
plan and the LPCI, established a 16-km (10-mi) buffer around the
estimated occupied range for planning and implementation purposes. This
approach, EOR + 10, was used for a variety of reasons. Most
importantly, this approach recognizes that the boundaries delineating
the occupied range are not static and may vary from year to year
depending on size of lesser prairie-chicken populations within the
respective polygon. Considering population size may vary annually, the
precise extent of the occupied range also may vary annually. This
approach helps ensure that all of the occupied range is captured during
planning efforts and is consistent with the action area used by the
LPCI. This approach also is consistent with the action area used by the
FSA for their section 7 consultation purposes. The area encompassed by
the EOR + 10 varies slightly by planning effort depending on how the
area was mapped and derived from geographical mapping software used in
geographical information systems. The rangewide plan estimates that the
EOR + 10 encompasses 162,478 sq km (62,733 sq mi) or 16,247,912 ha
(40,149,404 ac) (Van Pelt et al. 2013, p. 129). When the CHAT tool is
used to derive the EOR + 10, however, the extent is 16,653,390 ha
(41,151,360 ac) (Van Pelt et al. 2013, p. 137). During the development
of the final rangewide plan in the fall of 2013, the CHAT tool was
revised to account for additional information obtained by the States,
resulting in the difference of the EOR + 10 compared to the rangewide
plan. However, the CHAT decision support tool is a work in process and
is expected to continue to change as geospatial modeling techniques are
refined and additional datasets are obtained. Therefore, we used the
area presented in the rangewide plan as the EOR + 10 throughout this
final rule.
[[Page 20010]]
Although the mapped polygons used to determine the estimated
occupied range appear contiguous and may leave the impression that the
entire polygon is uniformly occupied by lesser prairie-chickens, such
is not the case. Over much of the area within each occupied polygon,
the habitat has been fragmented and provides suitable habitat in
patches of various sizes. Consequently, within each polygon designated
as occupied range, there will be areas that do not provide suitable
habitat and are unlikely to be occupied by lesser prairie-chickens. The
estimates of occupied range, in acres or hectares, are therefore not
accurate in the sense that they include areas that are not occupied but
were included in the larger mapping unit for calculation purposes. The
actual amount of occupied habitat is likely less than the areas, in
acres or hectares, presented in this discussion.
As derived from the estimated historical and occupied ranges
described above, the overall distribution of lesser prairie-chicken
within all States except Kansas has declined sharply since pre-European
settlement, and the species is generally restricted to variously sized,
often highly fragmented parcels of untilled native rangeland (Taylor
and Guthery 1980a, pp. 2-5) or areas with significant CRP enrollments
that were initially seeded with native grasses (Rodgers and Hoffman
2005, pp. 122-123). The estimated current occupied range, based on
cooperative mapping efforts described above, and as derived from
calculations of the area of each mapped polygon using geographical
information software, represents about an 84 percent reduction in
overall occupied range since pre-European settlement.
Rangewide Population Estimates
Very little information is available regarding the size of lesser
prairie-chicken populations prior to 1900. Once the five States
supporting lesser prairie-chickens were officially opened for
settlement beginning in the late 1800s, settlement occurred quickly and
the landscape began to change rapidly. Numbers of lesser prairie-
chickens likely changed rapidly as well. Despite the lack of conclusive
information on population size, the lesser prairie-chicken was
reportedly quite common throughout its range in Colorado, Kansas, New
Mexico, Oklahoma, and Texas in the early 20th century (Bent 1932, pp.
280-281, 283; Baker 1953, p. 8; Bailey and Niedrach 1965, p. 51; Sands
1968, p. 454; Fleharty 1995, pp. 38-44; Robb and Schroeder 2005, p.
13). Litton (1978, p. 1) suggested that as many as two million birds
may have occurred in Texas alone prior to 1900. By the 1930s, the
species had begun to disappear from areas where it had been considered
abundant, and the decline was attributed to extensive cultivation,
overgrazing by livestock, and drought (Bent 1932, p. 280). Populations
were nearly extirpated from Colorado, Kansas, and New Mexico, and were
markedly reduced in Oklahoma and Texas (Baker 1953, p. 8; Crawford
1980, p. 2).
Rangewide estimates of population size were almost nonexistent
until the 1960s and likely corresponded with more frequent and
consistent efforts by the States to monitor lesser prairie-chicken
populations. Although lesser prairie-chicken populations can fluctuate
considerably from year to year in response to variable weather and
habitat conditions, generally the overall population size has continued
to decline from the estimates of population size available in the early
1900s (Robb and Schroeder 2005, p. 13). By the mid-1960s, Johnsgard
(1973, p. 281) estimated the total rangewide population to be between
36,000 and 43,000 individuals. In 1980, the estimated rangewide fall
population size was thought to be between 44,400 and 52,900 birds
(Crawford 1980, p. 3). Population size in the fall is likely to be
larger than population estimates derived from spring counts due to
recruitment that occurs following the nesting season. By 2003, the
estimated total rangewide population was 32,000 birds, based on
information provided by the Lesser Prairie-Chicken Working Group (Rich
et al. 2004, unpaginated). Prior to the implementation of the rangewide
survey effort in 2012, the best available population estimates indicate
that the lesser prairie-chicken population likely would be
approximately 45,000 birds or fewer (see Table 2). This estimate is a
rough approximation of the maximum population size and should not be
considered as the actual current population size. Although the estimate
uses the most current information available, population estimates for
some States have not been determined in several years and reported
values may not represent actual population sizes. For example, the
values reported for Colorado and Oklahoma were published in 2000, and
recent estimates of total population size for these States have not
been determined. The aerial surveys conducted in 2012, as explained
below, provide the best estimate of current population size.
Table 2--Recent Population Estimates Prior to 2012 by State
[Modified from Hagen et al. 2010, p. 30]
------------------------------------------------------------------------
Recent population estimates
State prior to 2012
------------------------------------------------------------------------
Colorado.............................. < 1,500 (in 2000).
Kansas................................ 19,700-31,100 (in 2006).
New Mexico............................ 6,130 (in 2011).
Oklahoma.............................. < 3,000 (in 2000).
Texas................................. 1,254-2,649 (in 2010-11).
---------------------------------
TOTAL............................. < 45,000.
------------------------------------------------------------------------
In the spring (March 30 to May 3) of 2012, the States, in
conjunction with the Western Association of Fish and Wildlife Agencies,
implemented a rangewide sampling framework and survey methodology using
small aircraft. This aerial survey protocol was developed to provide a
more consistent approach for detecting rangewide trends in lesser
prairie-chicken population abundance across the occupied range. The
goal of this survey was to estimate the abundance of active leks and
provide information that could be used to detect trends in lek
abundance over time. The sampling framework used 15-by-15-km (9-by-9-
mi) grid cells overlapping the estimated occupied range, as existed in
2011, plus a 7.5-km (4.6-mi) buffer. Additional information on the
survey approach is provided in McDonald et al. 2011, entire.
The aerial survey study area was divided into four regions that
encompassed the estimated occupied range of the lesser prairie-chicken.
These regions were delineated largely based on habitat type and results
were not grouped by individual State. The four regional groupings were
the Shinnery Oak Prairie Region of eastern New Mexico and southwest
Texas; the Sand Sagebrush Prairie Region located in southeastern
Colorado, southwestern Kansas, and western Oklahoma Panhandle; the
Mixed Grass Prairie Region located in the northeastern Texas panhandle,
northwestern Oklahoma, and south-central Kansas; and the Short Grass/
CRP Mosaic in northwestern Kansas and eastern Colorado. During surveys
of the 264 blocks selected, 40 lesser prairie-chicken leks, 6 mixed
leks comprised of both lesser and greater prairie-chickens, and 100
non-lek aggregations of lesser prairie-chickens were observed (McDonald
et al. 2012, p. 15). For this particular study, an active lek was
defined as having five or more birds per lek. If fewer than five
individual birds were observed, ground surveys were conducted of those
bird groups to determine if lekking birds were present.
[[Page 20011]]
If not, those areas were classified as ``non-leks.'' After the survey
observations were adjusted to account for probability of detection
(standard method used to adjust counts to account for individuals
present but not detected), 3,174 lesser prairie-chicken leks were
estimated to occur over the entire occupied range (McDonald et al.
2012, p. 18). Another 441 mixed leks, consisting of both lesser and
greater prairie-chickens, were estimated to occur within the occupied
range. These mixed leks were limited to the Short Grass/CRP Mosaic
region where the range of the two species overlaps. Using the
respective average group size, by each identified region, an estimate
of the total number of lesser prairie-chickens and lesser/greater
prairie-chicken hybrids could be derived (McDonald et al. 2012, p. 20).
The total estimated abundance of lesser prairie-chickens was 37,170
individuals, with the number of hybrids estimated to be 309 birds
(McDonald et al. 2012, p. 21). The estimated total number of lesser
prairie-chicken leks and population size, by habitat region, are as
follows: Shinnery Oak Prairie Region--428 leks and 3,699 birds; Sand
Sagebrush Prairie Region--105 leks and 1,299 birds; Mixed Grass Prairie
Region--877 leks and 8,444 birds; and the Short Grass/CRP Mosaic
Region--1,764 leks and 23,728 birds (McDonald et al. 2012, pp. 20, 23).
In 2013, the States and the Western Association of Fish and
Wildlife Agencies repeated the aerial survey and reanalyzed the 2012
survey results based on ecoregion specific estimated population
parameters and a pooled analysis of the data for both years (McDonald
et al. 2013, entire). The revised total estimated abundance of lesser
prairie-chickens in 2012 was 34,440 individuals (90 percent upper and
lower confidence intervals of 52,076 and 21,718 individuals,
respectively; McDonald et al. 2013, p. 24). The total estimated
abundance of lesser prairie-chickens in 2013 dropped to 17,616
individuals (90 percent upper and lower confidence intervals of 20,978
and 8,442 individuals, respectively). The number of hybrids in 2012 was
estimated to be 350 birds (McDonald et al. 2013, p. 25). In 2013, the
number of hybrid birds was estimated to be 342. The estimated total
number of lesser prairie-chicken leks and population size, by
ecoregion, for 2012 are as follows: Shinnery Oak Prairie Region--366
leks and 2,946 birds; Sand Sagebrush Prairie Region--327 leks and 3,005
birds; Mixed Grass Prairie Region--794 leks and 8,076 birds; and the
Short Grass/CRP Mosaic Region--1,443 leks and 20,413 birds (McDonald et
al. 2012, pp. 24, 25). In 2013, the estimated total number of lesser
prairie-chicken leks and population size, by ecoregion, are as follows:
Shinnery Oak Prairie Region--118 leks and 1,967 birds; Sand Sagebrush
Prairie Region--323 leks and 1,802 birds; Mixed Grass Prairie Region--
356 leks and 3,567 birds; and the Short Grass/CRP Mosaic Region--1,240
leks and 10,279 birds (McDonald et al. 2012, pp. 24, 25).
Garton (2012, entire) used estimates of the minimum population size
derived from the 2012 aerial survey (McDonald et al. 2012, entire),
based on estimated rates of change and thetas (index of the relative
size of the previous year's population) as described in Garton et al.
(2011, p. 301) and past lek counts by the States to reconstruct
historical population levels over time. However, ground surveys within
the sand sage regions yielded higher estimated minimum population size
than did the aerial survey data, and Garton used the higher ground
survey results rather than that obtained from the aerial surveys in the
analysis for this particular ecoregion. Based on Garton's analysis,
lesser prairie-chicken populations generally increased during the mid-
1960s to early 1970s (Garton 2012, pp. 6, 11). Since the early 1970s to
the mid-1990s, the population experienced a long-term decline. The
reconstructed population estimate for 1970 was almost 300,000 birds but
had declined to less than 50,000 birds by the mid-1990s. Following the
mid-1990s, populations appear to have stabilized somewhat but at levels
considerably below those from the 1970s through the early 1990s (Garton
2012, pp. 6-11).
In June 2012, we were provided with an interim assessment of lesser
prairie-chicken population trends since 1997 (Hagen 2012, entire). The
objective of this analysis was to provide an evaluation of recent
lesser prairie-chicken population trends both rangewide and within the
four primary habitat types (CRP-shortgrass prairie dominated landscape,
mixed grass prairie landscape, sand sagebrush prairie landscape, and
shinnery oak landscape) that encompass the occupied range of the
species. The analysis employed modeling techniques intended to provide
a more unified assessment of population trends, considering that each
State uses slightly different methods to monitor lesser prairie-
chickens and that sampling effort has varied over time, with sampling
efforts typically increasing in recent years. The results of this
analysis suggest that lesser prairie-chicken population trends have
increased since 1997.
However, we are reluctant to place considerable weight on this
interim assessment for several reasons. First, and perhaps most
important, is that the analysis we were provided is a preliminary
product. We anticipated that a more complete, and perhaps peer-
reviewed, product would be submitted during the comment period on the
proposed rule; however, we did not receive an updated assessment.
Second, we have concerns with the differences in how lek counts are
conducted and how those differences were addressed. For example, when
the States conduct flush counts at the leks, all of the States, except
Oklahoma, count the number of males flushed from the lek. However,
since 1999, Oklahoma has counted all birds flushed from the lek and did
not differentiate between males and females. Additionally, some of the
States use numbers derived from lek counts conducted over large areas
rather than road side surveys. We are unsure how these differences in
sampling methodology would influence the pooled trend information
presented, particularly for large geographical areas where two
different sampling methods are used in the analysis. Third, the trend
information presents only information gathered since 1997 or more
recently, without considering historical survey information. The trends
evident from sampling efforts since 1997 likely reflect increased
sampling effort following publication of the Service's 12-month finding
(63 FR 31400, June 9, 1998), and increased sampling effort could lead
to biased results. Furthermore, trend analyses in general are dependent
upon the timeframe chosen. The population reconstruction information
used in Garton (2012, entire) shows that the lowest modeled abundance
occurred in 1997, the starting point of Hagen's analysis. Thus, it is
likely that a trend analysis for a different timeframe, dating either
further back or more recently than 1997, would result in a different
outcome. Further, Hagen's analysis does not consider the most recent
rangewide aerial survey results, which were used to derive a population
estimate of 17,616 individuals (90 percent upper and lower confidence
intervals of 20,978 and 8,442 individuals, respectively) in 2013
(McDonald et al. 2013, p. 24). This represents a substantial decrease
in population estimates compared to recent years and inclusion of the
2013 rangewide population estimates would likely change Hagen's
analysis.
[[Page 20012]]
In some instances, sampling methodology by agency likely varied
between years during the analyzed time period as access to some study
areas was restricted and new areas were established in their place. For
example, in southwest Texas, two study areas were used until 1999, when
an additional sampling area in Yoakum County was added. Then in 2007,
the original Gaines County study area was dropped and a new, smaller
Gaines County study area was established to replace the original study
area. Similar changes occurred in the northeastern panhandle of Texas
where a new study area in Gray County was added in 1998. These changes
in sampling location can confound efforts to make comparisons between
years. The interim assessment does not include an explanation regarding
how these changes were addressed.
We also recognize the limitations of using lek counts to derive
population trends over large areas. The deficiencies and limitations of
lek counts include that not all leks are known, making it difficult to
draw a random or representative sample from which to make inferences;
not all known leks are counted and those that are may not represent the
full set of known leks; leks may not be well-defined with sharply or
spatially defined boundaries; not all birds are present at a lek at any
given time, as influenced by the date, time of day, weather conditions,
the presence of predators, and other influences; the age composition of
birds at a lek varies seasonally; not all birds at a lek are counted;
and the number of times a lek is counted each year varies (Johnson and
Rowland 2007, pp. 17-20). Consequently, we caution against using
available data from lek counts to derive rangewide population trends as
these analyses can be misleading. However, information on historical
and recent lesser prairie-chicken population trends over large
geographical areas would improve our analysis of the status of the
species, and we support efforts to provide a reliable, accurate
analysis of rangewide population trends, particularly if those
analytical methods are repeatable over time and peer-reviewed.
State-by-State Information on Population Status
Each of the State conservation agencies within the occupied range
of the lesser prairie-chicken provided us with information regarding
the current population estimates of the lesser prairie-chicken within
their respective States, and most of the following information was
taken directly from agency reports, memos, and other status documents.
Population survey data are collected from spring lek surveys in the
form of one or both of the following indices: Average lek size (i.e.,
number of males or total birds per lek); or density of birds or leks
within a given area. Most typically, the data are collected along fixed
survey routes where the number of displaying males counted is assumed
to be proportional to the population size, or the number of leks
documented is assumed to be an index of population size or occupied
range. These techniques are useful in evaluating long-term trends and
determining occupancy and distribution but are very limited in their
usefulness for reliably estimating population size (Johnson and Rowland
2007, pp. 17-20). However, given existing constraints, such as
available staff and funding, they provide the best opportunity to
assess lesser prairie-chicken populations.
Although each State annually conducts lesser prairie-chicken
surveys according to standardized protocols, those protocols vary by
State. Thus, each State can provide information relative to lesser
prairie-chicken numbers and trends by State, but obtaining consistent
information across the entire range is difficult given the current
approach to population monitoring. However, in the absence of more
reliable estimators of bird density, total counts of active leks over
large areas were recommended as the most reliable trend index for
prairie grouse populations such as lesser prairie-chickens (Cannon and
Knopf 1981, p. 777; Hagen et al. 2004, p. 79).
Colorado--Lesser prairie-chickens were likely resident in six
counties (Baca, Bent, Cheyenne, Kiowa, Kit Carson, and Prowers
Counties) in Colorado prior to European settlement (Giesen 2000, p.
140). At present, lesser prairie-chickens are known to occupy portions
of Baca, Cheyenne, Prowers, and Kiowa Counties, but are not known to
persist in Bent or Kit Carson Counties. Present delineated range
includes portions of eastern Lincoln County where suitable habitat
persists, although breeding birds have not been documented from this
county. Populations in Kiowa and Cheyenne Counties number fewer than
100 individuals and appear to be isolated from other populations in
Colorado and adjacent States (Giesen 2000, p. 144). The lesser prairie-
chicken has been State-listed as threatened in Colorado since 1973.
Colorado Department of Wildlife (now CPW) estimated 800 to 1,000 lesser
prairie-chicken in the State in 1997. Giesen (2000, p. 137) estimated
the population size, as of 2000, to be fewer than 1,500 breeding
individuals (see Table 2, above).
CPW has been monitoring leks annually since 1959, primarily by
using standard survey routes (Hoffman 1963, p. 729). A new survey
method was initiated in 2004, designed to cover a much broader range of
habitat types and a larger geographic area, particularly to include
lands enrolled in the CRP. The new methodology resulted in the
discovery of more leks and the documented use of CRP fields by lesser
prairie-chickens in Colorado. In 2011, CPW used aerial surveys in
addition to the more traditional ground surveys in an attempt to
identify new leks in Cheyenne County (Remington 2011).
Lesser prairie-chicken populations in Colorado have declined
steadily since 2011, likely the result of deteriorating habitat
conditions due to prolonged drought (Smith 2013, pp. 1-3). In 2013, the
total number of birds counted was 84, down from 105 birds in 2012, and
161 birds in 2011 (Smith 2013, pp. 2-3). The number of active leks
detected in 2013 was 10, down from 14 in 2012, and 17 in 2011. For this
study, a lek is considered active when at least three males are
observed displaying on the lek. There were three active leks in Baca
County, four active leks in Prowers County, and three active leks in
Cheyenne County. One of the leks detected in Cheyenne County was
considered a new lek. The number of leks declined in all counties
except Cheyenne since 2011. In 2011, there were six active leks in Baca
County, nine active leks in Prowers County, and two active leks in
Cheyenne County (Verquer and Smith 2011, pp. 1-2). No active leks have
been detected in Kiowa County since 2008 (Verquer 2008, p. 1). Habitat
provided by CRP is likely to be important to persistence of lesser
prairie-chickens in Colorado.
The annual survey report provides information on the total count of
lesser prairie-chickens from 1977 to the present. Since 1977, the total
number of birds observed during routine survey efforts has varied from
a high of 448 birds in 1990, to a low of 74 birds in 2007. The general
population trajectory, based on number of birds observed on active leks
during the breeding season is declining, excluding information from
1992, when limited survey data were collected. The number of active
leks remained fairly stable between 1999 and 2006. During this period,
the highest number of active leks recorded, 34, occurred in 2004 and
again in 2006. The fewest number of active leks observed occurred in
2002, when 24 leks were observed. The average number of active
[[Page 20013]]
leks observed between 1999 and 2006 was 30.1.
Beginning in 2007 and continuing to present, the number of active
leks observed has remained fairly stable. Since 2007, the highest
recorded number of active leks was 18, which occurred in 2007. The
fewest number of active leks observed was 10 recorded in 2013. The
average number of active leks over this period was 16.4, roughly half
of the average number of active leks (30) observed during the period
between 1999 and 2006. Drought conditions observed in 2006, followed by
severe winter weather, probably account for the decline in the number
of lesser prairie-chickens observed in 2007 (Verquer 2007, pp. 2-3). In
the winter of 2006-2007, heavy snowfall severely reduced food and cover
in Prowers, southern Kiowa, and most of Baca Counties for over 60 days.
Then, in the spring of 2008, nesting and brood rearing conditions were
unfavorable due to drought conditions in southeastern Colorado (Verquer
2009, p. 5).
As a complement to, and included within, CPW surveys, counts are
completed on the USFS Comanche National Grassland in Baca County. On
the Comanche National Grassland, the estimated area occupied by the
lesser prairie-chicken over the past 20 years was approximately 27,373
ha (65,168 ac) (Augustine 2005, p. 2). Surveys conducted during 1984 to
2005 identified 53 different leks on or immediately adjacent to USFS
lands. Under this survey methodology, leks were identified based on the
presence of at least three birds on the lek. Lek censuses conducted
from 1980 to 2005 showed the number of males counted per lek since 1989
has steadily declined (Augustine 2006, p. 4). The corresponding
population estimate, based on number of males observed at leks, on the
Comanche National Grassland was highest in 1988, with 348 birds, and
was lowest in 2005, with approximately 64 birds and only 8 active leks
(Augustine 2006, p. 4). The estimate of males per lek in 2005 declined
more than 80 percent from that of 1988, from 174 males per lek to 32
males per lek, respectively. In 2009, each historical lek was surveyed
2 to 3 times, and 4 active leks were observed (Shively 2009b, p. 1). A
high count of 25 males was observed using these four leks. In the
spring of 2008, five active leks and 34 birds were observed (Shively
2009a, p. 3).
Kansas--In the early part of the last century, the lesser prairie-
chicken's historical range included all or part of 38 counties, but by
1977, the species was known to exist in only 17 counties, all located
south of the Arkansas River (Waddell and Hanzlick 1978, pp. 22-23).
Since 1999, biologists have documented lesser prairie-chicken expansion
and reoccupation of 17 counties north of the Arkansas River, primarily
attributable to favorable habitat conditions (e.g., native grasslands)
created by implementation of the CRP in those counties. Currently,
lesser prairie-chickens occupy approximately 34,479 sq km (13,312 sq
mi) within all or portions of 35 counties in western Kansas. Greater
prairie-chickens in Kansas also have expanded their range, and, as a
result, mixed leks of both lesser prairie-chickens and greater prairie-
chickens occur within an overlap zone covering portions of 7 counties
(2,500 sq km (965 sq mi)) in western Kansas (Bain and Farley 2002, p.
684). Within this zone, apparent hybridization between lesser prairie-
chickens and greater prairie-chickens is now evident (Bain and Farley
2002, p. 684). Three survey routes (162.65 sq km, 62.8 sq mi) used by
KDWPT are located within this overlap zone. Although hybrid individuals
are included in the counts, the number of hybrids observed is typically
less than 5 percent of the total number of individual birds observed on
the surveyed areas annually. In 2013, seven hybrid individuals,
representing 3 percent of the birds observed, were detected (Pitman
2013, p.10). These hybrids were detected on survey routes in Gove,
Ness, and Logan counties.
Since inception of standard lesser prairie-chicken survey routes in
1967, the number of standard survey routes has gradually increased. The
number of standard routes currently surveyed in Kansas for lesser
prairie-chickens is 14, and encompasses an area of 679.3 sq km (262.3
sq mi). Flush counts are taken twice at each lek located during the
standard survey routes. An estimated population density is calculated
for each route by taking the higher of the two flush counts, doubling
that count primarily to account for females, and then dividing the
estimated number of birds by the total area surveyed per route. The
current Statewide trend in lesser prairie-chicken abundance between
2004 and 2013 indicates a declining population (Pitman 2013, p. 15).
The KDWPT reported that recent declines are largely due to severe
drought, which negatively impacted habitat quality, and not to
significant habitat loss (Pitman 2013, p. 15).
In 2006, KDWPT estimated the breeding population of lesser prairie-
chickens in the State to be between 19,700 and 31,100 individuals
(Rodgers 2007a, p. 1). The total breeding population estimates were
derived using the National Gap Analysis Program, where the population
indices from each habitat type along 15 survey routes were extrapolated
for similar habitat types throughout total occupied lesser prairie-
chicken range Statewide.
New Mexico--In the 1920s and 1930s, the former range of the lesser
prairie-chicken in New Mexico was described as all of the sand hill
rangeland of eastern New Mexico, from Texas to Colorado, and as far
west as Buchanan in DeBaca County. Ligon (1927, pp. 123-127) mapped the
breeding range at that time as encompassing portions of seven counties,
a small subset of what he described as former range. Ligon (1927, pp.
123-127) depicted the historical range in New Mexico as encompassing
all or portions of 12 counties. In the 1950s and 1960s, occupied range
was more extensive than the known occupied range in 1927 (Davis 2005,
p. 6), indicating reoccupation of some areas since the late 1920s.
Presently, the NMDGF reports that lesser prairie-chickens are known
from six counties (Chaves, Curry, DeBaca, Lea, Roosevelt, and Quay
Counties) and suspected from one additional county (Eddy County). The
occupied range of the lesser prairie-chicken in New Mexico is
conservatively estimated to encompass approximately 5,698 sq km (2,200
sq mi) (Davis 2006, p. 7) compared with its historical range of 22,390
sq km (8,645 sq mi). Based on the cooperative mapping efforts conducted
by the Playa Lakes Joint Venture and the Lesser Prairie-Chicken
Interstate Working Group, occupied range in New Mexico was estimated to
be 8,570 sq km (3,309 sq mi), considerably larger than the conservative
estimate used by Davis (2006, p. 7). One possible reason for the
difference in occupied range is that Davis (2006, p. 7) did not
consider the known distribution to encompass any portion of Eddy County
or southern Lea County. Approximately 59 percent of the historical
lesser prairie-chicken range in New Mexico is privately held, with the
remaining historical and occupied range occurring on lands managed by
the BLM, USFS, and New Mexico State Land Office (Davis 2005, p. 12).
In the 1950s, the lesser prairie-chicken population in New Mexico
was estimated at 40,000 to 50,000 individuals, but, by 1968, the
population had declined to an estimated 8,000 to 10,000 individuals
(Sands 1968, p. 456). Johnsgard (2002, p. 51) estimated the number of
lesser prairie-chickens in New Mexico at fewer than 1,000 individuals
by 2001. Similarly,
[[Page 20014]]
the Sutton Center estimated the New Mexico lesser prairie-chicken
population to number between 1,500 and 3,000 individuals, based on
observations made over a 7-year period from the late 1990s to mid-2000s
(Wolfe 2007, pers. comm.). Using lek survey data, NMDGF currently
estimates the Statewide lesser prairie-chicken population in 2013 to be
about 1,705 birds (Beauprez 2013, p. 6). This is the lowest estimated
spring breeding population observed since 2001 and represents a 72
percent decline in estimated population size since 2011 (Beauprez 2013,
pp. 16-17). The total number of leks detected in 2013 also was the
lowest on record (Beauprez 2013, p. 16). Longer term trends are not
available as roadside listening routes did not become established until
1998. Prior to that date, counts were conducted on some of the NMDGF
Prairie Chicken Areas or on lands under the jurisdiction of the BLM.
The current roadside survey uses 29 standard routes established since
1999, 10 additional routes established in 2003 within the northeastern
part of lesser prairie-chicken historical range, and 41 routes randomly
selected from within the 382 townships located within the survey
boundary. The NMGF reported that population declines observed since
2011 are believed to be at least partially attributed to poor nesting
and brood rearing habitat due to the persistent drought (Beauprez 2013,
p. 17).
Since initiating the 10 additional northeastern routes in 2003,
NMDGF reports that no leks have been detected in northeastern New
Mexico. Results provide strong evidence that lesser prairie-chickens no
longer occupy their historical range within Union, Harding, and
portions of northern Quay Counties (Beauprez 2009, p. 8). However, a
solitary male lesser prairie-chicken was observed and photographed in
northeastern New Mexico by a local wildlife law enforcement agent in
December 2007. Habitat in northeastern New Mexico appears capable of
supporting lesser prairie-chickens, but the lack of any known leks in
this region since 2003 suggests that lesser prairie-chicken populations
in northeastern New Mexico, if still present, are very small.
The core of occupied lesser prairie-chicken range in this State
lies in east-central New Mexico (Chaves, Curry, DeBaca, Lea, and
Roosevelt Counties). Populations in southeastern New Mexico, defined as
the area south of U.S. Highway 380, remain low and continue to decline.
The majority of historically occupied lesser prairie-chicken habitat in
southeastern New Mexico occurs primarily on BLM land. Snyder (1967, p.
121) suggested that this region is only marginally populated except
during favorable climatic periods. Best et al. (2003, pp. 225, 232)
concluded anthropogenic factors including, but not limited to,
incompatible livestock grazing, habitat conversion, and shrub control
have, in part, rendered lesser prairie-chicken habitat south of U.S.
Highway 380 inhospitable for long-term survival of lesser prairie-
chickens in southeastern New Mexico. Similarly, NMDGF suggests that
habitat quality likely limits recovery of populations in southeastern
New Mexico (Beauprez 2009, p. 13).
The New Mexico State Game Commission owns and manages 30 Prairie
Chicken Areas ranging in size from 10.5 to 3,171 ha (29 to 7,800 ac)
within the core of occupied range in east central New Mexico. These
Prairie Chicken Areas total approximately 109 sq km (42 sq mi), or
roughly 1.6 percent of the total occupied lesser prairie-chicken range
in New Mexico. Instead of the typical roadside counts, the NMDGF
conducts ``saturation'' surveys on each individual Prairie Chicken Area
to determine the presence of lesser prairie-chicken leks and individual
birds over the entire Prairie Chicken Area (Beauprez 2013, p. 8). Lands
adjacent to the Prairie Chicken Areas are included within these
surveys, including other State Trust Lands, some adjacent BLM lands,
and adjacent private lands. The results of these saturation counts are
included in their estimate of the spring breeding population size. The
Prairie Chicken Areas are important to persistence of the lesser
prairie-chicken in New Mexico. However, considering the overall extent
of the Prairie Chicken Areas and that many Prairie Chicken Areas are
small and isolated, continued management of the surrounding private,
Federal and trust lands is integral to viability of the lesser prairie-
chicken in New Mexico.
Oklahoma--Lesser prairie-chickens historically occurred in 22
Oklahoma counties. By 1961, Copelin (1963, p. 53) reported lesser
prairie-chickens from only 12 counties. By 1979, lesser prairie-
chickens were verified in eight counties, and the remaining population
fragments encompassed an estimated area totaling 2,792 sq km (1,078 sq
mi), a decrease of approximately 72 percent since 1944. At present, the
ODWC reports lesser prairie-chickens continue to persist in eight
counties with an estimated occupied range of approximately 950 sq km
(367 sq mi). Horton (2000, p. 189) estimated the entire Oklahoma lesser
prairie-chicken population numbered fewer than 3,000 birds in 2000. A
more recent estimate has not been conducted.
The ODWC is aware of 96 known historical and currently active leks
in Oklahoma. During the mid-1990s, all of these leks were active.
Systematic survey efforts to document the current number of active leks
over the occupied range were completed in 2011. About 220 survey routes
were conducted over 11 counties in northwestern Oklahoma (Larsson et
al. 2012, p. 1). In total, 72 active leks were detected. No leks were
detected in either Cimarron or Beckham Counties.
The number of roadside listening routes currently surveyed annually
in Oklahoma has varied from five to seven over the last 20 years, and
counts of the number of males per lek have been conducted since 1968.
Beginning with the 2002 survey, male counts at leks were replaced with
flush counts, which did not differentiate between the sexes of birds
flushed from the surveyed lek (ODWC 2007, pp. 2, 6). Comparing the
total number of males observed during survey efforts between the years
1977 through 2001 reveals a declining trend. However, the overall
density of leks (number per sq mi), another means of evaluating
population status of lesser prairie-chickens, for five of the standard
routes since 1985 is stable to slightly declining. Information on lek
density prior to 1985 was unavailable. The standard route in Roger
Mills County was not included in this analysis because the lek was
rarely active and has not been surveyed since 1994. A survey route in
Woods County was included in the analysis even though surveys on this
route did not begin until 2001. However, excluding the Woods County
route did not alter the apparent trend. The average lek density since
2001 is 0.068 leks per sq mi (Schoeling 2010, p. 3). Between 1985 and
2000, the average lek density was 0.185 leks per sq mi, when the route
in Roger Mills County is excluded from the analysis. Over the last 10
years, the density of active leks has varied from a low of 0.02 leks
per sq km (0.05 leks per sq mi) in 2004, 2006, and 2009, to a high of
0.03 leks per sq km (0.09 leks per sq mi) in 2005 and 2007 (Schoeling
2010, p. 3).
Texas--Systematic surveys to identify Texas counties inhabited by
lesser prairie-chickens began in 1940 (Henika 1940, p. 4). From the
early 1940s (Henika 1940, p. 15; Sullivan et al. 2000) to mid-1940s
(Litton 1978, pp. 11-12), to the early 1950s (Seyffert 2001, pp. 108-
112), the range of the lesser prairie-chicken in Texas was estimated to
encompass all or portions of 34 counties. Species experts considered
the occupied range at that
[[Page 20015]]
time to be a reduction from the presettlement range. By 1989, TPWD
estimated occupied range encompassed all or portions of only 12
counties (Sullivan et al. 2000, p. 179). In 2005, TPWD reported that
the number of occupied counties likely has not changed since the 1989
estimate. In March 2007, TPWD reported that lesser prairie-chickens
were confirmed from portions of 13 counties (Ochiltree, Lipscomb,
Roberts, Hemphill, Gray, Wheeler, Donley, Bailey, Lamb, Cochran,
Hockley, Yoakum, and Terry Counties) and suspected in portions of
another 8 counties (Moore, Carson, Oldham, Deaf Smith, Randall,
Swisher, Gaines, and Andrews Counties).
Based on aerial and road surveys conducted in 2010 and 2011, new
leks were detected in Bailey, Cochran, Ochiltree, Roberts, and Yoakum
Counties, expanding the estimated occupied ranges in those counties
(TPWD 2011). However, no lesser prairie-chickens were detected in
Andrews, Carson, Deaf Smith, Oldham, or Randall Counties. Active leks
were reported from the same 13 counties identified in 2007. However, in
2012, Timmer (2012, pp. 36, 125-131) observed lesser prairie-chickens
in only 12 counties: Bailey, Cochran, Deaf Smith, Donley, Gray,
Hemphill, Lipscomb, Ochiltree, Roberts, Terry, Wheeler, and Yoakum.
Lesser prairie-chicken populations in Texas primarily persist in two
disjunctive regions--the Permian Basin/Western Panhandle region and the
Northeastern Panhandle region.
Maximum occupied range in Texas, as of September 2007, was
estimated to be 12,787 sq km (4,937.1 sq mi), based on habitat
conditions in 20 panhandle counties (Davis et al. 2008, p. 23).
Conservatively, based on those portions of the 13 counties where lesser
prairie-chickens are known to persist, the area occupied by lesser
prairie-chickens in Texas is 7,234.2 sq km (2,793.1 sq mi). Using an
estimated mean density of 0.0088 lesser prairie-chickens per ac (range
0.0034-0.0135 lesser prairie-chickens per ac), the Texas population was
estimated at a mean of 15,730 individuals in the 13 counties where
lesser prairie-chickens are known to occur (Davis et al. 2008, p. 24).
Since 2007, Texas has been evaluating the usefulness of aerial
surveys as a means of detecting leks and counting the number of birds
attending the identified lek (McRoberts 2009, pp. 9-10). Initial
efforts focused on measuring lek detectability and assessing the
response of lekking birds to disturbance from survey aircraft. More
recently, scientists at Texas Tech University used aerial surveys to
estimate the density of lesser prairie-chicken leks and Statewide
abundance of lesser prairie-chickens in Texas. This study conducted an
inventory of 208 survey blocks measuring 7.2 by 7.2 km (4.5 by 4.5 mi),
encompassing some 87 percent of the occupied range in Texas during the
spring of 2010 and 2011 (Timmer 2012, pp. 26-27, 33). Timmer (2012, p.
34) estimated 2.0 leks per 100 sq km (0.02 leks per sq km). Previously
reported estimates of rangewide average lek density varied from 0.10 to
0.43 leks per sq km (Davison 1940; Sell 1979; Giesen 1991; Locke 1992
as cited in Hagen and Giesen 2005, unpaginated). The total estimate of
the number of leks was 293.6 and, based on the estimated number of
birds observed using leks, the statewide population was determined to
be 1,822.4 lesser prairie-chickens (Timmer 2012, p. 34).
Lesser prairie-chicken population trends in Texas, based on annual
monitoring efforts, have been declining over the last 15 years (1997-
2012), with the exception of the Bailey County Study Area (Martin 2013,
p. 9). However the Bailey County Study Area has not been surveyed since
2007, so recent trend information from this area is unavailable. Since
2010, the overall average number of males per lek have declined, but
the density of leks (number per square mile) has remained fairly
constant (Martin 2013, p. 11).
Summary of Population Status Information
Lesser prairie-chicken populations are distributed over a
relatively large area, and these populations can fluctuate considerably
from year to year, a natural response to variable weather and habitat
conditions. Changes in lesser prairie-chicken breeding populations may
be indicated by a change in the number of birds attending a lek (lek
size), the number of active leks, or both. Although each State conducts
standard surveys for lesser prairie-chickens, the application of survey
methods and effort varies by State. Such factors complicate
interpretation of population indices for the lesser prairie-chicken and
may not reliably represent actual populations. Caution should be used
in evaluating population trajectories, particularly short-term trends.
In some instances, short-term analyses could reveal statistically
significant changes from one year to the next but actually represent a
stable population when evaluated over longer periods of time. For
example, increased attendance of males at leks may be evident while the
number of active leks actually declined.
An examination of anecdotal information on historical numbers of
lesser prairie-chickens indicates that numbers likely have declined
from possibly millions of birds to current estimates of thousands of
birds. Examination of the trends in the five lesser prairie-chicken
States for most indicator variables, such as males per lek and lek
density, over the last 3 years shows the trends are indicative of
declining populations. Much of these recent declines are due, at least
in part, to habitat degradation resulting from incidence of severe
drought over much of the occupied range. Habitat conditions may improve
with the return of more normal precipitation patterns in the near
future. However, the numbers of lesser prairie-chickens reported per
lek are considerably fewer than the numbers reported during the 1970s.
While habitat conditions may improve in the future, the low lek
attendance observed at many leks is likely due to longer term
reductions in population size. It is unlikely that populations will
recover to historical levels observed just 40 years ago, particularly
when considered in light of the loss and alteration, including
fragmentation, of lesser prairie-chicken habitat throughout its
historical range over the past several decades. Information regarding
habitat loss and fragmentation, as well as other factors, impacting the
lesser prairie-chicken is provided in the sections that follow.
Summary of Factors Affecting the Species
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a significant portion of its
range'' and a threatened species as any species ``that is likely to
become endangered throughout all or a significant portion of its range
within the foreseeable future.'' Thus, a species may be listed as a
threatened species if it is likely to qualify for endangered status in
the foreseeable future, or in other words, likely to become ``in danger
of extinction'' within the foreseeable future. The Act does not define
the term ``foreseeable future.'' However, in a January 16, 2009,
memorandum addressed to the Acting Director of the Service, the Office
of the Solicitor, Department of the Interior, concluded, ``. . . as
used in the [Act], Congress intended the term `foreseeable future' to
describe the extent to which the Secretary can reasonably rely on
predictions about the future in making determinations about the future
conservation status of the species'' (M-37021, January 16, 2009).
[[Page 20016]]
In considering the foreseeable future as it relates to the status
of the lesser prairie-chicken, we considered the factors acting on the
species and looked to see if reliable predictions about the status of
the species in response to those factors could be drawn. We considered
the historical data to identify any relevant existing trends that might
allow for reliable prediction of the future (in the form of
extrapolating the trends). We also considered whether we could reliably
predict any future events that might affect the status of the species,
recognizing that our ability to make reliable predictions into the
future is limited by the variable quantity and quality of available
data.
Under section 4(a)(1) of the Act, we determine whether a species is
an endangered or threatened species because of any of the following
five factors: (A) The present or threatened destruction, modification,
or curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; and (E) other natural or manmade factors affecting its
continued existence. Listing actions may be warranted based on any of
the above threat factors, singly or in combination.
After a review of the best available scientific information as it
relates to the status of the species and the five listing factors
described above, we have determined that the lesser prairie-chicken
meets the definition of a threatened species (i.e., is likely to become
in danger of extinction in the foreseeable future throughout all or a
significant portion of its range). Following, we present a very brief
explanation of the rationale leading to this conclusion followed by an
in-depth discussion of the best available scientific information.
The range of the lesser prairie-chicken has been reduced by an
estimated 84 percent (see discussion above in ``Current Range and
Distribution''). The primary factor responsible for the range reduction
is habitat fragmentation due to a variety of mechanisms that contribute
to habitat loss and alteration. This habitat loss significantly
increases the extinction risk for the lesser prairie-chicken because
the species requires large parcels of intact native grassland and
shrubland, often in excess of 8,100 ha (20,000 ac) to maintain self-
sustaining populations (Woodward et al. 2001, p. 261; Flock 2002, p.
130; Fuhlendorf et al. 2002a, p. 618; Davis 2005, p. 3). Further, the
life history of the species, primarily its lek breeding system and
behavioral avoidance of vertical structures that increase predation
risk, make it especially vulnerable to ongoing impacts on the
landscape, especially at its currently reduced numbers. The total
estimated population abundance in 2013 dropped to 17,616 individuals
(90 percent upper and lower confidence intervals of 20,978 and 8,442
individuals, respectively) from 34,440 individuals (90 percent upper
and lower confidence intervals of 52,076 and 21,718 individuals,
respectively) in 2012 (McDonald et al. 2013, p. 24). Finally, the
species has a reduced population size and faces ongoing habitat loss
and degradation. The species will lack sufficient redundancy and
resiliency to ensure its viability from present and future threats.
While the current status of the lesser prairie-chicken has been
substantially compromised by historical and current threats, there
appear to be sufficient stable populations to ensure the persistence of
the species over the near term. That is, the Service does not believe
the species is currently at risk of extinction. However, as a result of
continued population declines predicted into the future, the species is
likely to become in danger of extinction in the foreseeable future.
Following, we present our analysis of the best available scientific
and commercial data that has led to this conclusion.
Habitat Fragmentation
Spatial habitat fragmentation occurs when some form of disturbance,
usually habitat alteration or loss, results in the separation or
splitting apart of larger, previously contiguous, functional components
of habitat into smaller, often less valuable, noncontiguous parcels
(Wilcove et al. 1986, p. 237; Johnson and Igl 2001, p. 25; Franklin et
al. 2002, entire). Fragmentation influences habitat availability and
quality in three primary ways: Total area of available habitat; size of
habitat patches, including edge effects; and patch isolation (Johnson
and Igl 2001, p. 25; Stephens et al. 2003, p. 101). Initially,
reduction in the total area of available habitat (i.e., habitat loss)
may be more significant than fragmentation and can exert a much greater
effect of extinction (Fahrig (1997, pp. 607, 609). However, as habitat
loss continues, the effects of fragmentation often compound effects of
habitat loss and produce even greater population declines than habitat
loss alone (Bender et al. 1998, pp. 517-518, 525). At the point where
some or all of the remaining habitat fragments or patches are below
some minimum required size, the impact of additional habitat loss, when
it consists of inadequately sized parcels, is minimal (Herkert 1994, p.
467). In essence, once a block of suitable habitat becomes so
fragmented that the size of the remaining patches become biologically
unsuitable, the continued loss of these smaller, suitable patches, is
of little further consequence to the species (Bender et al. 1998, p.
525).
Both habitat loss and fragmentation correlate with an ecological
concept known as carrying capacity. Within any given block or patch of
habitat, carrying capacity is the maximum number of organisms that can
be supported indefinitely within that area, provided sufficient food,
space, water, and other necessities are available, without causing
degradation of the habitat within that patch. Theoretically, as habitat
loss increases and the size of an area shrinks, the maximum number of
individuals that could inhabit that particular habitat patch also would
decline. Consequently, a reduction in the total area of available
habitat can negatively influence biologically important characteristics
such as the amount of space available for establishing territories and
nest sites (Fahrig 1997, p. 603). Over time, the continued conversion
and loss of habitat to other land uses will reduce the ability of the
land to support historical population levels, causing a decline in
population sizes. Where the ability to effect restoration of these
habitats is lost, the observed reduction in fish or wildlife
populations is likely to be permanent.
Fragmentation not only contributes to overall habitat loss but also
causes a reduction in the size of individual habitat patches and
influences the proximity of these patches to other patches of similar
habitat (Stephens et al. 2003, p. 101; Fletcher 2005, p. 342). Habitat
quality for many species is a function of fragment size and declines as
the size of the fragment decreases (Franklin et al. 2002, p. 23).
Fahrig and Merriam (1994, p. 53) reported that both the size and shape
of the fragment have been shown to influence population persistence in
many species. The size of the fragment can influence reproductive
success, survival, and movements. As the distance between habitat
fragments increases, dispersal between the habitat patches may become
increasingly limited and ultimately cease, impacting population
persistence and potentially leading to both localized and regional
extinctions (Harrison and Bruna 1999, p. 226; With et al. 2008, p.
3153).
The proportion of habitat edge to interior habitat increases as the
size of a fragment declines. The edge is the transition zone between
the original
[[Page 20017]]
habitat type and the adjacent altered habitat. In contrast, the core is
the area within a fragment that remains intact and is largely or
completely uninfluenced by the margin or edge of the fragment. Edge
habitat proliferates with increasing fragmentation (Sisk and Battin
2002, p. 31). The response of individual species to the presence of
edges varies markedly depending on their tolerance to the edge and the
nature of its effects (Sisk and Battin 2002, p. 38). The effects often
depend on the degree of contrast between the habitat edge and the
adjacent land use matrix. The transition can be abrupt or something
more gradual and less harsh. Most typically, edges to influence
movements and survival, particularly for species that use interior or
core habitats, serve as points of entry for parasites and predators
(such as presence of fences adjacent to grasslands which provide
hunting perches for avian predators), alter microclimates, subsidize
feeding opportunities (such as providing access to waste grains in
cropland areas), and influence species interactions, particularly with
cosmopolitan species that tend to be habitat generalists (Sisk and
Battin 2002, p. 38).
Fragmentation also can influence the heterogeneity or variation
within the resulting fragment. Heterogeneity, in turn, influences the
quality of the habitat within the fragment, with more homogeneous
fragments generally being less valuable. Grasslands tend to be
structurally simple and have little vertical layering. Instead, habitat
heterogeneity tends to be largely expressed horizontally rather than
vertically (Wiens 1974b, pp. 195-196). Prior to European settlement,
the interaction of grazing by wild ungulates, drought and fire created
a shifting mosaic of vegetative patches having various composition and
structure (Derner et al. 2009, p. 112; Pillsbury et al. 2011, p. 2).
Under these conditions, many grassland birds distribute their
behavioral activities unevenly throughout their territories by nesting
in one area, displaying in another, and foraging in still others (Wiens
1974b, p. 208). Lesser prairie-chickens exhibit this pattern and cue on
specific vegetation structure and microenvironment features depending
on the specific phase of their life cycle. Consequently, blocks of
habitat that collectively or individually encompass multiple
successional states that comprise tall grasses and shrubs needed for
nesting, and are in proximity to more open grasslands supporting forbs
for brood rearing, and are combined with smaller areas of short grass
and bare ground used for breeding, support all of the habitat types
used by lesser prairie-chickens throughout the year. Considering
habitat diversity tends to be greater in larger patches, finding the
appropriate mosaic of these features is more likely in larger fragments
rather than smaller fragments (Helzer and Jelinski 1999, p. 1456).
Such habitat heterogeneity is very different from habitat
fragmentation. Habitat fragmentation occurs when the matrix separating
the resulting fragments is converted to a use that is not considered
habitat whereas habitat heterogeneity implies that patches each having
different vegetative structure exist within the same contiguous block
of habitat. Habitat heterogeneity may influence habitat quality, but it
does not represent fragmentation (Franklin et al. 2002, p. 23).
Isolation is another factor that influences suitability of habitat
fragments. As habitat loss continues to progress over time, the
remnants not only become smaller and more fragmented, they become more
isolated from each other. When habitat patches become more isolated and
the amount of unusable, unsuitable land use surrounding the islands of
habitat increases, even patches of suitable quality and size may no
longer be occupied. As fragmentation progresses, the ability of
available dispersers to locate suitable fragments will decline. At some
point, the amount of intervening unusable and unsuitable land
comprising the matrix between the patches grows so wide that it exceeds
the organism's dispersal capabilities, rendering the matrix impermeable
to dispersal. In such instances, colonizers are unavailable to occupy
the otherwise suitable habitat and reestablish connectivity. While
extinctions at the local level, and subsequent recolonization of the
vacant patch, are common phenomena, recolonization depends on the
availability of dispersing individuals and their ability to disperse
within the broader landscape (Fahrig and Merriam 1994, p. 52). Without
available dispersing individuals with the ability to disperse, these
isolated patches may remain vacant indefinitely. When the number of
individuals at the landscape or regional level that are available to
disperse declines, the overall population begins to decline and will,
in turn, affect the number of individuals available to disperse.
Connectivity between habitat patches is one means of facilitating
dispersal, but the appropriate size or configuration of the dispersal
corridors needed to facilitate connectivity for many species is
unknown. The rangewide plan (Van Pelt et al. 2013, p. 77), delineates
connectivity zones based on criteria that provide a foundation upon
which to base suitable dispersal corridors for the lesser prairie-
chicken. Suitable dispersal corridors should contain at least 40
percent good to high quality habitat, be at least 8 km (5 mi) wide and
contain few, if any, features, such as roads or transmission lines,
that function as barriers to movement. Additionally, suitable habitat
patches within a corridor should be separated by no more than 3.2 km (2
mi). In the absence of specific studies that define suitable dispersal
corridors, the criteria provided in the rangewide plan (Van Pelt et al.
2013, p. 77) provide suitable guidelines that can be used to facilitate
development of appropriate dispersal corridors.
Causes of Habitat Fragmentation Within Lesser Prairie-Chicken Range
A number of factors can cause or contribute to habitat
fragmentation. Generally, fragmentation can result from the direct loss
or alteration of habitat due to conversion to other land uses or from
habitat alteration which indirectly leaves the habitat in such a
condition that the remaining habitat no longer functionally provides
the preferred life-history requisites needed to support breeding or
feeding or to provide shelter. Functional habitat impacts can include
disturbances that alter the existing successional state of a given
area, create a physical barrier that precludes use of otherwise
suitable areas, or triggers a behavioral response by the organism such
that otherwise suitable habitats are abandoned or no longer used.
Fragmentation tends to be most significant when human developments are
dispersed across the landscape rather than being concentrated in fewer
areas. Anthropogenic causes of fragmentation tend to be more
significant than natural causes because the organism has likely evolved
in concert with the natural causes.
Initially, settlement and associated land use changes had the
greatest influence on fragmentation in the Great Plains. Knopf (1994,
p. 249) identified four universal changes that occurred in Great Plains
grasslands postsettlement, based on an evaluation of observations made
by early explorers. These changes were identified as a change in the
native grazing community, cultivation, wetland conversion, and
encroachment of woody vegetation.
EuroAmerican settlement of much of the Great Plains began in
earnest with passage of the Homestead Act of 1862.
[[Page 20018]]
Samson et al. (2004, p. 7) estimated that about 1.5 million people
acquired over 800,000 sq km (309,000 sq mi) of land through the
Homestead Act, mostly within the Great Plains region. Continued
settlement and agricultural development of the Great Plains during the
late 1800s and early 1900s, facilitated by railroad routes and cattle
and wagon trails, contributed to conversion and fragmentation of once
open native prairies into an assortment of varied land uses and habitat
types such as cultivated cropland, expanding cedar woodlands, and
remnants of grassland (NRCS 1999, p. 1; Coppedge et al. 2001, p. 47;
Brennan and Kuvlesky 2005, pp. 2-3). This initial settlement altered
the physical characteristics of the Great Plains and the biodiversity
found in the prairies (Samson et al. 2004, p. 7). Changes in
agricultural practices and advancement of modern machinery combined
with an increasing demand for agricultural products continued to spur
conversion of native prairies well into the mid-1900s (NRCS 1999a, p.
2). Increasing human population densities in rural areas of the Great
Plains led to construction of housing developments as growing cities
began to expand into the surrounding suburban landscapes. Development
and intensification of unsuitable land uses in these urbanizing
landscapes also contributed to conversion and fragmentation of
grasslands, further reducing richness and abundance of avian
populations (Perlut et al. 2008, p. 3149; Hansen et al. 2011, p. 826).
See additional discussions related to population growth and settlement
below.
Oil and gas development began during the mid to late 1800s.
Eventually, invention of the automobile in the early twentieth century
and its rise to prominence as the primary mode of personal
transportation stimulated increased exploration and development of oil
and gas (Hymel and Wolfsong 2006, p. 4). Habitat loss and fragmentation
associated with access roads, drill pads, pipelines, waste pits, and
other components typically connected with exploration and extraction of
oil and gas are considered to be among the most significant ecological
impacts from oil and gas development and the impacts often extend
beyond the actual physical structures (Weller et al. 2002, p. 2). See
the section on energy development below for related discussion.
Information on human population size and growth in the five lesser
prairie-chicken States is collected by the U.S. Census Bureau, and
recent trends have been reported by the USDA Economic Research Service
(2013). Population size in each of the five States has grown since
1980. The percent population growth since 2010 varies from a low of 1.1
percent in Kansas to a high of 3.6 percent in Texas. Examination of
growth in human populations within rural areas reveals that rural
populations also have grown in every State except Kansas since 1980. In
Kansas, rural population size during this period peaked in 1980.
Human population trends within the counties that encompass the
estimated occupied range of the lesser prairie-chicken were
inconsistent and varied considerably across the range. For example, in
Colorado since 2010, human populations declined by about 1 percent in
both Baca and Prowers counties but populations in both Cheyenne and
Kiowa counties grew by at least 2.1 percent. However, since 1990,
populations in all four counties have declined. Similar trends were
observed in Oklahoma with five counties having a declining population
and four showing increasing human populations since 2010. But unlike
Colorado, three counties within the estimated occupied range in
Oklahoma have increased in population size since 1990. In New Mexico,
most, but not all, of the counties within the estimated occupied range
of the lesser prairie-chicken have increased since 1990.
We used projections of human population growth, based on U.S.
Census Bureau data, developed by the U.S. Forest Service for their
Forest and Rangeland Renewable Resources Planning Act of 1974 (RPA)
Assessment to forecast how human populations within the estimated
historical and occupied ranges of the lesser prairie-chicken would
change into the future. The USFS used a medium population growth
scenario, taking the implications of climate change into consideration,
to predict how human populations nationwide would change between 2010
and 2060 (U.S. Forest Service 2012, entire). Using the counties
encompassed within the historical and estimated occupied range, we were
able to determine, by range within the respective States, how human
populations would be projected to change by 2060.
In Colorado within the historical range, two of the six counties
were projected to experience a decline in human population while the
remaining four counties were expected to see an increase in human
population growth rate. The overall net gain in population size over
the 50 year period was 3,490 individuals. Within the four counties
located within the estimated occupied range, projected population size
was predicted to decline in two counties and increase in two counties.
The overall net gain in human population size within the estimated
occupied range in Colorado by 2060 was 280 individuals.
In the Kansas historical range, 29 counties were projected to
experience a decline in human population while the remaining 13
counties were expected to see an increase in population. The overall
net gain in population size over the 50 year period in the 29 counties
within the Kansas historical range was 22,376 individuals. Within just
the counties located within the estimated occupied range, projected
population size was predicted to decline in 24 counties and increase in
11 counties. The overall net gain in human population size within the
Kansas portion of the estimated occupied range by 2060 was 39,190
individuals.
In Oklahoma, similar trends for both the historical and estimated
occupied ranges were predicted. Nineteen counties within the historical
range were projected to experience a decline in human population. The
overall net gain in population size over the 50 year period within the
estimated historical range was 85,310 individuals. Within the nine
counties that comprise the estimated occupied range, projected
population size was predicted to decline in seven counties and increase
in two counties. The overall net gain in human population size within
the Oklahoma estimated occupied range by 2060 was 5,830 individuals.
In Texas, where the largest extent of historical range occurs,
human population growth was projected to be larger than those projected
in the previous three States. Within the historical range, 43 counties
were projected to experience a decline in human population while the
remaining 51 counties were projected to see an increase in population.
The overall net gain in population size over the 50 year period in the
counties within the estimated historical range was 368,770 individuals.
Within the estimated occupied range of Texas, human populations were
projected to decline in 12 counties and increase in eight counties. The
overall net gain in human population size within the estimated occupied
range by 2060 was 61,780 individuals.
Population growth in New Mexico is expected to be more substantial
than in the other States. Within the historical range, only two
counties were projected to experience a decline in human population
while the remaining nine counties were projected see an increase in
population. The overall net gain in
[[Page 20019]]
human population size over the 50 year period in the counties within
the estimated historical range was estimated to be 89,380 individuals.
Within the counties located within the estimated occupied range,
projected population size was predicted to decline in one county and
increase in six counties. The projected overall net gain in human
population size within the New Mexico portion of the estimated occupied
range by 2060 was 81,690 individuals.
Overall, within the historical range human population growth is
projected to experience a net increase in human population by 2060 of
about 569,326 individuals or 1.2 individuals per sq km (3.2 per sq mi).
The estimated occupied range is projected to experience a net increase
in human population by 2060 of about 188,770 individuals or 2.3
individuals per sq km (6.04 per sq mi). Human population density, based
on the projected population growth, within the estimated occupied range
is projected to increase by almost double that of the entire historical
range.
As human populations continue to expand, as projected, the growth
is expected to alter the landscape by modifying land use patterns much
like the changes that occurred during settlement of the Great Plains.
Forecasts of human population growth through the year 2060 revealed
that nationwide the land area encompassed by urbanization will increase
by 24 million ha (59 million ac) to 35 million ha (86 million ac),
depending on whether a slower or more rapid growth scenario is used in
the analysis (Wear 2011, p. 14). Increases in land area under urban
development are expected to result in reductions in the area that is in
cropland, pastureland and rangeland. Forecasts of cropland loss vary
between 7.6 million ha (19 million ac) and 11 million ha (28 million
ac), depending on which growth scenario is selected. Under the scenario
of intermediate levels of human population growth and strong growth in
personal income, about 85 percent (9.7 million ha; 24 million ac) of
the cropland losses would occur in regions along and east of the
Mississippi River and in coastal areas (Wear 2011, pp. 15, 22, 24).
Forecasts of rangeland loss vary between 3.2 million ha (8 million ac)
and 4.4 million ha (12 million ac), depending on which growth scenario
is selected. Colorado and Texas are projected to experience some of the
greatest losses of rangeland (Wear 2011, p. 23). In general, human
populations in the Great Plains are expected to remain unchanged or
decline slightly by 2060, particularly in the Oklahoma and Texas
panhandles and portions of western and central Kansas (Wear 2011, p.
13).
As human populations, as projected, continue to expand,
particularly into rural regions outside of existing urban and suburban
areas, an increasing array of human features such as powerlines,
highways, secondary roads, communication towers, and other types of
infrastructure necessary to support these human populations are
expected to appear on the landscape (Leu et al. 2008, p. 1119). We
believe this infrastructure tends to remain in place even if human
populations decline after initial expansion. Often these developments
can degrade ecosystem functions and lead to fragmentation even when the
overall development footprint is relatively small.
Natural vertical features, such as trees and man-made, above ground
vertical structures such as power poles, fence posts, oil and gas
wells, towers, and similar developments can cause general habitat
avoidance and displacement in lesser prairie-chickens and other prairie
grouse (Anderson 1969, entire; Robel 2002, entire; Robel et al. 2004,
entire; Hagen et al. 2004, entire; Pitman et al. 2005, entire; Pruett
et al. 2009a, entire; Hagen et al. 2011, entire; Hovick et al.
unpublished manuscript, entire). This avoidance behavior is presumably
a behavioral response that serves to limit exposure to predation. The
observed avoidance distances can be much larger than the actual
footprint of the structure and appear to vary depending upon the type
of structure. These structures can have significant negative impacts by
contributing to further fragmentation of otherwise suitable habitats.
Hovick et al. (unpublished manuscript under review, entire) examined
the influence of several anthropogenic structures, including oil and
gas infrastructure, powerlines and wind turbines on displacement
behavior and survival in grouse. They conducted a meta-analysis that
examined 23 different structures and found that all structure types
examined resulted in displacement but oil structures and roads had the
greatest impact on grouse avoidance behavior (Hovick et al. unpublished
manuscript under review, p. 11). They also examined the effect of 17 of
these structures on survival and found all of the structures examined
also decreased survival in grouse, with lek attendance declining at a
greater magnitude than other survival parameters measured (Hovick et
al. unpublished manuscript under review, p. 12).
Prairie grouse, such as the lesser prairie-chicken, did not evolve
with tall, vertical structures present on the landscape and, in
general, have low tolerance for tall structures. As discussed in
``Altered Fire Regimes and Encroachment by Invasive, Woody Plants''
below, encroachment of trees into native grasslands preferred by lesser
prairie-chickens ultimately renders otherwise suitable habitat
unsuitable unless steps are taken to remove these trees. Even placement
of cut trees in a pattern that resembled a wind break were observed to
cause an avoidance response. Anderson (1969, pp. 640-641) observed that
greater prairie-chickens abandoned lek territories when a 4-m (13-ft)
tall coniferous wind break was artificially erected 52 m (170 ft) from
an active lek.
Increasingly, man-made vertical structures are appearing in
landscapes used by lesser prairie-chickens. The placement of these
vertical structures in open grasslands represents a significant change
in the species' environment and is a relatively new phenomenon over the
evolutionary history of this species. The effects of these structures
on the life history of prairie grouse are only beginning to be
evaluated, with similar avoidance behaviors also having been observed
in sage grouse (75 FR 13910, March 23, 2010).
Robel (2002, p. 23) reported that a single commercial-scale wind
turbine creates a habitat avoidance zone for the greater prairie-
chicken that extends as far as 1.6 km (1 mi) from the structure. Lesser
prairie-chickens likely exhibit a similar response to tall structures,
such as wind turbines (Pitman et al. 2005, pp. 1267-1268). The Lesser
Prairie-Chicken Interstate Working Group (Mote et al. 1999, p. 27)
identified the need for a contiguous block of 52 sq km (20 sq mi) of
high-quality rangeland habitat to successfully maintain a local
population of lesser prairie-chicken. Based on this need and the fact
that the majority of remaining populations are fragmented and isolated
into islands of unfragmented, open prairie habitat, the Service
recommended that an 8-km (5-mi) voluntary no-construction buffer be
established around prairie grouse leks to account for behavioral
avoidance and to protect lesser prairie-chicken populations and habitat
corridors needed for future recovery (Manville 2004, pp. 3-4). In
Kansas, no lesser prairie-chickens were observed nesting or lekking
within 0.8 km (0.5 mi) of a gas line compressor station, and otherwise
suitable habitat was avoided within a 1.6-km (1-mi) radius of a coal-
fired power plant (Pitman et al. 2005, pp. 1267-1268). Pitman et al.
(2005, pp. 1267-1268) also observed that female lesser prairie-chickens
selected nest sites that were significantly further from powerlines,
roads, buildings, and oil and gas wellheads than would be expected at
random. Specifically, they
[[Page 20020]]
observed that lesser prairie-chickens seldom nested or reared broods
within approximately 177 m (580 ft) of oil or gas wellheads, 400 m
(1,312 ft) of electrical transmission lines, 792 m (2,600 ft) of
improved roads, and 1,219 m (4,000 ft) of buildings; and, the observed
avoidance was likely influenced, at least in part, by disturbances such
as noise and visual obstruction associated with these features.
Similarly, Hagen et al (2004, p. 75) indicated that areas used by
lesser prairie-chickens were significantly further from these same
types of features than areas that were not used by lesser prairie-
chickens. They concluded that the observed avoidance was likely due to
potential for increased predation by raptors or due to presence of
visual obstructions on the landscape (Hagen et al. 2004, pp. 74-75).
Robel et al. (2004, pp. 256-262) determined that habitat
displacement associated with avoidance of certain structures by lesser
prairie-chickens can be substantial, collectively exceeding 21,000 ha
(53,000 ac) in a three-county area of southwestern Kansas. Using
information on existing oil and gas wells, major powerlines (115 kV and
larger), and existing wind turbines and proposed wind energy
development in northwestern Oklahoma, Dusang (2011, p. 61) modeled the
effect of these anthropogenic structures on lesser prairie-chicken
habitat in Oklahoma. He estimated that existing and proposed
development of these structures potentially would eliminate
approximately 960,917 ha (2,374,468 ac) of nesting habitat for lesser
prairie-chickens, based on what is currently known about their
avoidance of these structures.
Avoidance of vertical features such as trees and transmission lines
likely is due to frequent use of these structures as hunting perches by
birds of prey (Hagen et al. 2011, p. 72). Raptors actively seek out and
use power poles and similar aboveground structures in expansive
grassland areas where natural perches are limited. In typical lesser
prairie-chicken habitat where vegetation is low and the terrain is
relatively flat, power lines and power poles provide attractive
hunting, loafing, and roosting perches for many species of raptors
(Steenhof et al. 1993, p. 27). The elevated advantage of transmission
lines and power poles serve to increase a raptor's range of vision,
allow for greater speed during attacks on prey, and serve as
territorial markers. While the effect of avian predation on lesser
prairie-chickens depends on raptor densities, as the number of hunting
perches or structures to support nesting by raptors increase, the
impact of avian predation will increase accordingly (see separate
discussion under ``Predation'' below). The perception that these
vertical structures are associated with predation may cause lesser
prairie-chickens to avoid areas near these structures even when raptor
densities are low. Sensitivity to electromagnetic fields generated by
the transmission lines may be another reason lesser prairie-chickens
might be avoiding these areas (Fernie and Reynolds 2005, p. 135) (see
separate discussion under ``Wind Power and Energy Transmission
Operation and Development'' below).
Where grassland patches remained, overgrazing, drought, lack of
fire, woody plant and exotic grass invasions, and construction of
various forms of infrastructure impacted the integrity of the remaining
fragments (Brennan and Kuvlesky 2005, pp. 4-5). Domestic livestock
management following settlement tended to promote more uniform grazing
patterns, facilitated by construction of fences, which led to reduced
heterogeneity in remaining grassland fragments (Fuhlendorf and Engle
2001, p. 626; Pillsbury et al. 2011, p. 2). See related discussions in
the relevant sections below.
This ever-escalating fragmentation and homogenization of grasslands
contributed to reductions in the overall diversity and abundance of
grassland-endemic birds and caused populations of many species of
grassland-obligate birds, such as the lesser prairie-chicken to decline
(Coppedge et al. 2001, p. 48; Fuhlendorf and Engle, 2001, p. 626).
Fragmentation and homogenization of grasslands is particularly
detrimental for lesser prairie-chickens that typically prefer areas
where individual habitat needs are in close proximity to each other.
For example, in suitable habitats, desired vegetation for nesting and
brood rearing typically occurs within relatively short distances of the
breeding area.
Effects of Habitat Fragmentation
While much of the conversion of native grasslands to agriculture in
the Great Plains was largely completed by the 1940s and has slowed in
more recent decades, grassland bird populations continue to decline
(With et al. 2008, p. 3153). Bird populations may initially appear
resistant to landscape change only to decline inexorably over time
because remaining grassland fragments may not be sufficient to prevent
longer term decline in their populations (With et al. 2008, p. 3165).
The decrease in patch size and increase in edges associated with
fragmentation are known to have caused reduced abundance, reduced nest
success, and reduced nest density in many species of grassland birds
(Pillsbury et al. 2011, p. 2).
Habitat fragmentation has been shown to negatively impact
population persistence and influence the species extinction process
through several mechanisms (Wilcove et al. 1986, p. 246). Once
fragmented, the remaining habitat fragments may be inadequate to
support crucial life-history requirements (Samson 1980b, p. 297). The
land-use matrix surrounding remaining suitable habitat fragments may
support high densities of predators or brood parasites (organisms that
rely on the nesting organism to raise their young), and the probability
of recolonization of unoccupied fragments decreases as distance from
the nearest suitable habitat patch increases (Wilcove et al. 1986, p.
248; Sisk and Battin 2002, p. 35). Invasion by undesirable plants and
animals is often facilitated around the perimeter or edge of the patch,
particularly where roads are present (Weller et al. 2002, p. 2).
Additionally, as animal populations become smaller and more isolated,
they are more susceptible to random (stochastic) events and reduced
genetic diversity via drift and inbreeding (Keller and Waller 2002, p.
230). Population viability depends on the size and spacing of remaining
fragments (Harrison and Bruna 1999, p. 226; With et al. 2008, p. 3153).
O'Connor et al. (1999, p. 56) concluded that grassland birds, as a
group, are particularly sensitive to habitat fragmentation, primarily
due to sensitivity to fragment size. Consequently, the effects of
fragmentation are the most severe on area-sensitive species (Herkert
1994, p. 468).
Area-sensitive species are those species that respond negatively to
decreasing habitat patch size (Robbins 1979, p. 198; Finch 1991, p. 1.
An increasing number of studies are showing that many grassland birds
also are area-sensitive and have different levels of tolerance to
fragmentation of their habitat (e.g., see Herkert 1994, entire; Winter
and Faaborg 1999, entire). For species that are area-sensitive, once a
particular fragment or patch of suitable habitat falls below the
optimum size, populations decline or disappear entirely even though
suitable habitat may continue to exist within the larger landscape.
When the overall amount of suitable habitat within the landscape
increases, the patch size an individual area-sensitive bird may utilize
generally tends to be smaller (Horn and Koford 2006, p. 115), but they
appear to maintain some minimum threshold
[[Page 20021]]
(Fahrig 1997, p. 608; NRCS 1999a, p. 4). Winter and Faaborg (1999, pp.
1429, 1436) reported that the greater prairie-chicken was the most
area-sensitive species observed during their study, and this species
was not documented from any fragment of native prairie less than 130 ha
(320 ac) in size. Sensitivity of lesser prairie-chickens likely is very
similar to that of greater prairie-chickens; a more detailed discussion
is provided below.
Franklin et al. (2002, p. 23) described fragmentation in a
biological context. According to Franklin et al. (2002, p. 23) habitat
fragmentation occurs when occupancy, reproduction, or survival of the
organism has been affected. The effects of fragmentation can be
influenced by the extent, pattern, scale, and mechanism of
fragmentation (Franklin et al. 2002, p. 27). Habitat fragmentation also
can have positive, negative, or neutral effects, depending on the
species (Franklin et al. 2002, p. 27). As a group, grouse are
considered to be particularly intolerant of extensive habitat
fragmentation due to their short dispersal distances, specialized food
habits, generalized antipredator strategies, and other life-history
characteristics (Braun et al. 1994, p. 432). Lesser prairie-chickens in
particular have a low adaptability to habitat alteration, particularly
activities that fragment suitable habitat into smaller, less valuable
pieces. Lesser prairie-chickens use habitat patches with different
vegetative structure dependent upon a particular phase in their life
cycle, and the loss of even one of these structural components can
significantly reduce the overall value of that habitat to lesser
prairie-chickens. Fragmentation not only reduces the size of a given
patch but also can reduce the interspersion or variation within a
larger habitat patch, possibly eliminating important structural
features crucial to lesser prairie-chickens.
Lesser prairie-chickens and other species of prairie grouse require
large expanses (i.e., 1,024 to 10,000 ha (2,530 to 24,710 ac)) of
interconnected, ecologically diverse native rangelands to complete
their life cycles (Woodward et al. 2001, p. 261; Flock 2002, p. 130;
Fuhlendorf et al. 2002a, p. 618; Davis 2005, p. 3), more so than almost
any other grassland bird (Johnsgard 2002, p. 124). Davis (2005, p. 3)
states that the combined home range of all lesser prairie-chickens at a
single lek is about 49 sq km (19 sq mi or 12,100 ac). According to
Applegate and Riley (1998, p. 14), a viable lek will have at least six
males accompanied by an almost equal number of females. Because leks
need to be clustered so that interchange among different leks can occur
in order to reduce interbreeding problems on any individual lek, they
considered a healthy population to consist of a complex of six to ten
viable leks (Applegate and Riley 1998, p. 14). Consequently, most
grouse experts consider the lesser prairie-chicken to be an area-
sensitive species, and large areas of intact, unfragmented landscapes
of suitable mixed-grass, short-grass, and shrubland habitats are
considered essential to sustain functional, self-sustaining populations
(Giesen 1998, pp. 3-4; Bidwell et al. 2002, pp. 1-3; Hagen et al. 2004,
pp. 71, 76-77). Therefore, areas of otherwise suitable habitat can
readily become functionally unusable due to the effects of
fragmentation.
The lesser prairie-chicken has several life-history traits common
to most species of grouse that influence its vulnerability to the
impacts of fragmentation, including short lifespan, low nest success,
strong site fidelity, low mobility, and a relatively small home range.
This vulnerability is heightened by the considerable extent of habitat
loss that has already occurred over the range of the species. The
resiliency and redundancy of these populations have been reduced as the
number of populations that formerly occupied the known historical range
were lost or became more isolated by fragmentation of that range.
Isolation of remaining populations will continue to the extent these
populations remain or grow more separated by areas of unsuitable
habitat, particularly considering their limited dispersal capabilities
(Robb and Schroeder 2005, p. 36).
Fragmentation is becoming a particularly significant ecological
driver in lesser prairie-chicken habitats, and several factors are
known to be contributing to the observed destruction, modification, or
curtailment of the lesser prairie-chicken's habitat or range. Extensive
grassland and untilled rangeland habitats historically used by lesser
prairie-chickens have become increasingly scarce, and remaining areas
of these habitat types continue to be degraded or fragmented by
changing land uses. The loss and fragmentation of the mixed-grass,
short-grass, and shrubland habitats preferred by lesser prairie-
chickens has contributed to a significant reduction in the extent of
the estimated occupied range that is inhabited by lesser prairie-
chickens. Based on the cooperative mapping efforts led by the Playa
Lakes Joint Venture and Lesser Prairie-Chicken Interstate Working
Group, lesser prairie-chickens are estimated to now occupy only about
16 percent of their estimated historical range. What habitat remains is
now highly fragmented (Hagen et al. 2011, p. 64). See previous
discussion above in ``Current Range and Distribution'' for additional
detail.
Several pervasive factors, such as conversion of native grasslands
to cultivated agriculture; change in the historical grazing and fire
regime; tree invasion and brush encroachment; oil, gas, and wind energy
development; and road and highway expansion have been implicated in not
only permanently altering the Great Plains landscape but in
specifically causing much of the observed loss, alteration, and
fragmentation of lesser prairie-chicken habitat (Hagen and Giesen 2005,
np.; Elmore et al. 2009, pp. 2, 10-11; Hagen et al. 2011, p. 64).
Additionally, lesser prairie-chickens actively avoid areas of human
activity and noise or areas that contain certain vertical features,
such as buildings, oil or gas wellheads and transmission lines (Robel
et al. 2004, pp. 260-262; Pitman et al. 2005, pp. 1267-1268; Hagen et
al. 2011, p. 70-71). Avoidance of vertical features such as trees and
transmission lines likely is due to frequent use of these structures as
hunting perches by birds of prey (Hagen et al. 2011, p. 72). .
Oil and gas development activities, particularly drilling and road
and highway construction, also contribute to surface fragmentation of
lesser prairie-chicken habitat for many of the same reasons observed
with other artificial structures (Hunt and Best 2004, p. 92). The
incidence of oil and gas exploration has been rapidly expanding within
the range of the lesser prairie-chicken. A more thorough discussion of
oil and gas activities within the range of the lesser prairie-chicken
is discussed below.
Many of the remaining habitat fragments and adjoining land use
types subsequently fail to meet important habitat requirements for
lesser prairie-chickens. Other human-induced developments, such as
buildings, fences, and many types of vertical structures, which may
have an overall smaller physical development footprint per unit area,
serve to functionally fragment otherwise seemingly suitable habitat;
this causes lesser prairie-chickens to cease or considerably reduce
their use of habitat patches impacted by these developments (Hagen et
al. 2011 pp. 70-71). As the intervening matrix between the remaining
fragments of suitable habitat becomes less suitable for the lesser
prairie-chicken, dispersal patterns can be disrupted, effectively
isolating remaining islands of habitat. These
[[Page 20022]]
isolated fragments then become less resilient to the effects of change
in the overall landscape and likely will be more prone to localized
extinctions. The collective influence of habitat loss, fragmentation,
and disturbance effectively reduces the size and suitability of the
remaining habitat patches. Pitman et al. (2005, p. 1267) calculated
that nesting avoidance at the distances they observed would effectively
eliminate some 53 percent (7,114 ha; 17,579 ac) of otherwise suitable
nesting habitat within their study area in southwestern Kansas. Once
the remaining habitat patches fall below the minimum size required by
individual lesser prairie-chickens, these patches become uninhabitable
even though they may otherwise provide optimum habitat characteristics.
Although a minimum patch size per individual has not been established,
and will vary with the quality of the habitat, studies and expert
opinion, including those regarding greater prairie-chickens, suggest
that the minimum patch size is likely to exceed 100 ha (250 acres) per
individual (Samson 1980b, p. 295; Winter and Faaborg 1999, pp. 1429,
1436; Davis 2005, p. 3). Specifically for lesser prairie-chickens,
Giesen (1998, p. 11) and Taylor and Guthery (1980b, p. 522) reported
home ranges of individual birds varied from 211 ha (512 ac) to 1,945 ha
(4,806 ac) in size.
Fragmentation poses a threat to the persistence of local lesser
prairie-chicken populations through many of the same mechanisms
identified for other species of grassland birds. Factors such as
habitat dispersion and the extent of habitat change, including patch
size, edge density, and total rate of landscape change influence
juxtaposition and size of remaining patches of rangeland such that they
may no longer be large enough to support populations (Samson 1980b, p.
297; Woodward et al. 2001, pp. 269-272; Fuhlendorf et al. 2002a, pp.
623-626). Additionally, necessary habitat heterogeneity may be lost,
and habitat patches may accommodate high densities of predators.
Ultimately, lesser prairie-chicken interchange among suitable patches
of habitat may decrease, possibly affecting population and genetic
viability (Wilcove et al. 1986, pp. 251-252; Knopf 1996, p. 144).
Predation can have a major impact on lesser prairie-chicken demography,
particularly during the nesting and brood-rearing seasons (Hagen et al.
2007, p. 524). Patten et al. (2005b, p. 247) concluded that habitat
fragmentation, at least in Oklahoma, markedly decreases the probability
of long-term population persistence in lesser prairie-chickens.
Many of the biological factors affecting the persistence of lesser
prairie-chickens are exacerbated by the effects of habitat
fragmentation. For example, human population growth and the resultant
accumulation of infrastructure such as roads, buildings, communication
towers, and powerlines contribute to fragmentation. We expect that
construction of vertical infrastructure such as transmission lines will
continue to increase into the future, particularly given the increasing
development of energy resources and urban areas (see ``Wind Power and
Energy Transmission Operation and Development'' below). Where this
infrastructure is placed in occupied lesser prairie-chicken habitats,
the lesser prairie-chicken likely will be negatively affected. As the
density and distribution of human development continues in the future,
direct and functional fragmentation of the landscape will continue. The
resultant fragmentation is detrimental to lesser prairie-chickens
because they rely on large, expansive areas of contiguous native
grassland to complete their life cycle. Given the large areas of
contiguous grassland needed by lesser prairie-chickens, we expect that
many of these types of developments anticipated in the future will
further fragment remaining blocks of suitable habitat and reduce the
likelihood of persistence of lesser prairie-chickens over the long
term. Long-term persistence is reduced when the suitability of the
remaining habitat patches decline, further contributing to the scarcity
of suitable contiguous blocks of habitat and resulting in increased
human disturbance as parcel size declines. Human populations are
increasing throughout the range of the lesser prairie-chicken, and we
expect this trend to continue. Given the demographic and economic
trends observed over the past several decades, residential development
will continue.
The cumulative influence of habitat loss and fragmentation on
lesser prairie-chicken distribution is readily apparent at the regional
scale. Lesser prairie-chicken populations in eastern New Mexico and the
western Texas Panhandle are isolated from the remaining populations in
Colorado, Kansas, and Oklahoma. On a smaller, landscape scale, core
populations of lesser prairie-chickens within the individual States are
isolated from other nearby populations by areas of unsuitable land uses
(Robb and Schroeder 2005, p. 16). Then, at the local level within a
particular core area of occupied habitat, patches of suitable habitat
have been isolated from other suitable habitats by varying degrees of
unsuitable land uses. Very few large, intact patches of suitable
habitat remain within the historically occupied landscape.
We conducted two analyses of fragmentation. The first analysis was
conducted in 2012 prior to publication of the proposed rule; this was a
spatial analysis of the extent of fragmentation within the estimated
occupied range of the lesser prairie-chicken. Infrastructure features
such as roads, transmission lines, airports, cities and similar
populated areas, oil and gas wells, and other vertical features such as
communication towers and wind turbines were delineated. These features
were buffered by known avoidance distances and compared with likely
lesser prairie-chicken habitat such as that derived from the Southern
Great Plains Crucial Habitat Tool and 2008 LandFire vegetation cover
types. Based on this analysis, 99.8 percent of the suitable habitat
patches were less than 2,023 ha (5,000 ac) in size. Our analysis
revealed only 71 patches that were equal to, or larger than, 10,117 ha
(25,000 ac) exist within the entire five-state estimated occupied
range. Of the patches over 10,117 ha (25,000 ac), all were impacted by
fragmenting features, just not to the extent that the patch was
fragmented into a smaller sized patch. For example, oil and gas wells
or vertical features like wind turbines may occur within these large
patches but don't create a hard edge or barrier completely separating
one patch from another; rather, these types of fragmenting features may
create a mosaic of unsuitable lesser prairie-chicken habitat within the
large patch, thereby affecting the habitat quality of the area.
The Service's 2012 spatial analysis was a conservative estimate of
the extent of fragmentation within the estimated occupied range. We
only used readily available datasets. Some datasets were unavailable,
such as the extent of fences, and other infrastructural features were
not fully captured because our datasets were incomplete for those
features. Unfortunately, a more precise quantification of the impact of
habitat loss and alteration on persistence of the lesser prairie-
chicken is complicated by a variety of factors including time lags in
response to habitat changes and a lack of detailed historical
information on habitat conditions.
To better quantify the extent of fragmentation within the estimated
occupied range using the most recent data sets we could obtain and the
buffer distances reported in the rangewide
[[Page 20023]]
plan (Van Pelt et al. 2013, p. 95), we conducted a second spatial
analysis of fragmentation during preparation of the final rule. We used
existing data sources to identify natural grass and shrubland landcover
types within the estimated occupied range. This data was used in the
analysis to depict potential suitable vegetation where lesser prairie-
chickens may occur but does not necessarily identify existing lesser
prairie-chicken habitat or correlate with known lek locations. We took
this approach because the more refined data sets do not yet exist to
our knowledge. We then added the buffered existing data sets on
threats, which included roads, developed areas, oil and gas wells,
vertical structures, and transmission lines. This analysis served to
quantify spatial information on the scope and scale of fragmentation
and intactness of the potential suitable vegetation landcover types
within the estimated occupied range. Based on this analysis, we found
that 128,525 patches encompassing 3,562,168 ha (8,802,290.4 ac) of
potential suitable vegetation exists within the estimated occupied
range. Table 3, below, displays the breakdown in size and area of those
patches. The patch size ranges we analyzed are based on the information
provided in the discussion of minimum sizes of habitat blocks provided
in the rangewide plan (Van Pelt et al. 2013, p. 19).
Table 3--Potential Suitable Vegetation Patch Size Analysis Results
----------------------------------------------------------------------------------------------------------------
Patch size Number of patches Total area of patches
----------------------------------------------------------------------------------------------------------------
Less than 486 ha (1,200 ac)....... 127,190 1,588,262.4 ha (3,924,681.8 ac).
486-6,474 ha (1,200-15,999 ac).... 1,302 1,636,012 ha (4,042,673.7 ac).
6,475-8,497 ha (16,000-20,999 ac). 13 96,761.4 ha (239,102.6 ac).
Greater than 8,498 ha (21,000 ac). 20 241,124.8 ha (595,832.3 ac).
-----------------------------------------------------------------------------
TOTAL......................... 128,525 3,562,168 ha (8,802,290.4 ac).
----------------------------------------------------------------------------------------------------------------
When we conducted the second spatial analysis of fragmentation
during preparation of the final rule, we also prepared a proximity
analysis to help us achieve a better sense of how the various patches
in the natural grass and shrubland landcover types relate to each other
on the landscape. The proximity analysis groups individual patches, as
described above, that are only separated by rural roads. These rural
roads fragment the grass and shrub landscape, but they may not always
prevent the species from moving between patches. Groups of patches (or
remaining individual patches) under 64.7 ha (160 ac) were not included
in this analysis. Because these areas were not included, the proximity
model accounts for only 37 percent of all patches mapped in the patch
analysis (47,157 patches in the proximity analysis compared to 128,525
patches in the patch analysis), but it also accounts for 93 percent of
the total patch size acreage. Table 4, below, displays the breakdown in
size and area of the various proximity groups (groups of patches).
Table 4--Potential Suitable Vegetation Proximity Size Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Individual
Proximity group Count patches within Acreage
group
--------------------------------------------------------------------------------------------------------------------------------------------------------
64.7-485 ha (160-1,199 ac).................... 1,219 3,122 173,705.3 ha (429,235.2 ac).
485-6,474 ha (1,200-15,999 ac)................ 302 9,054 529,566.3 ha (1,308,586.9 ac).
6,475-8,497 ha (16,000-20,999 ac)............. 11 1,172 78,718.9 ha (194,518.7 ac).
8,498-20,234 ha (21,000-49,999 ac)............ 37 9,685 511,464.9 ha (1,263,857.4 ac).
20,234-40,468 ha (50,000-99,999 ac)........... 19 7,162 545,478.0 ha (1,347,905.6 ac).
Greater than 40,468 ha (100,000 ac)........... 22 16,962 1,481,324.0 ha (3,660,431.2 ac).
---------------------------------------------------------------------------------------------------------
TOTAL..................................... 1,610 47,157 3,562,168 ha (8,204,535.0 ac).
--------------------------------------------------------------------------------------------------------------------------------------------------------
In summary, habitat fragmentation is an ongoing threat that is
occurring throughout the estimated occupied range of the lesser
prairie-chicken. While 127,190 patches of potentially suitable
vegetation are less than 486 ha (1,200 ac), only 20 patches of
potentially suitable vegetation greater than 8,498 ha (21,000 ac)
remain. Similarly, much of the historical range is disjunct and
separated by large expanses of unsuitable habitat. In comparison to the
patch size analysis, the proximity analysis shows that there are 1,219
proximity groups that are less than 4856 ha (1,200 ac) and 78 proximity
groups that are greater than 8,498 ha (21,000 ac). Fragmentation
impacts the lesser prairie-chicken by altering the juxtaposition of
suitable habitat patches, by reducing the size of the available habitat
patches causing those patches to be smaller than necessary to support
stable to expanding populations, reducing the quality of the remaining
habitat patches, eliminating the habitat heterogeneity needed to
sustain all life history requirements of the species, facilitating
increased density of predators that leads to increased rates of
predation, and impacting the ability of lesser prairie-chickens to
disperse between suitable patches of habitat. Once fragmented, most of
the factors contributing to habitat fragmentation cannot be reversed
and the effects are cumulative. Many types of human developments likely
will exist for extended time periods and will have a significant,
lasting adverse influence on persistence of lesser prairie-chickens.
Therefore, current and future habitat fragmentation is a threat to the
lesser prairie-chicken. In many of the sections that follow, we will
examine in more detail the various causes of habitat fragmentation we
identified within the estimated occupied range of the five States that
support lesser prairie-chickens.
Habitat Conversion for Agriculture
At the time the lesser prairie-chicken was determined to be
taxonomically
[[Page 20024]]
distinct from the greater prairie-chicken in 1885, much of the
historical range was already being altered as settlement of the Great
Plains progressed. EuroAmerican settlement in New Mexico and Texas
began prior to the 1700s, and at least one trading post already had
been established in Colorado by 1825 (Coulson and Joyce 2003, pp. 34,
41, 44). Kansas had become a territory by 1854 and had already
experienced an influx of settlers due to establishment of the Santa Fe
Trail in 1821 (Coulson and Joyce 2003, p. 37). Western Oklahoma was the
last area to experience extensive settlement with the start of the land
run in 1889.
Settlement, as previously discussed, brought about many changes
within the historical range of the lesser prairie-chicken. Between 1915
and 1925, considerable areas of prairie had been plowed in the Great
Plains and planted to wheat (Laycock 1987, p. 4). By the 1930s, the
lesser prairie-chicken had begun to disappear from areas where it had
been considered abundant with populations nearing extirpation in
Colorado, Kansas, and New Mexico, and markedly reduced in Oklahoma and
Texas (Davison 1940, p.62; Lee 1950, p.475; Baker 1953, p.8; Oberholser
1974, p. 268; Crawford 1980, p. 2). Several experts on the lesser
prairie-chicken identified conversion of native sand sagebrush and
shinnery oak rangeland to cultivated agriculture as an important factor
in the decline of lesser prairie-chicken populations (Copelin 1963, p.
8; Jackson and DeArment 1963, p. 733; Crawford and Bolen 1976a, p. 102;
Crawford 1980, p. 2; Taylor and Guthery 1980b, p. 2; Braun et al. 1994,
pp. 429, 432-433; Mote et al. 1999, p. 3). By the 1930s, Bent (1932,
pp. 283-284) concluded that extensive cultivation and overgrazing had
already caused the species to disappear from portions of the historical
range where lesser prairie-chickens had once been abundant. Additional
areas of previously unbroken grassland were brought into cultivation in
the 1940s, 1970s, and 1980s (Laycock 1987, pp. 4-5; Laycock 1991, p.
2). Bragg and Steuter (1996, p. 61) estimated that by 1993, only 8
percent of the bluestem-grama association and 58 percent of the
mesquite-buffalo grass association, as described by Kuchler (1964,
entire), remained.
As the amount of native grasslands and untilled native rangeland
declined in response to increasing settlement, the amount of suitable
habitat capable of supporting lesser prairie-chicken populations
declined accordingly. Correspondingly, as the amount of available
suitable habitat diminished, carrying capacity was reduced and the
number of lesser prairie-chickens declined. Although the literature
supports that lesser prairie-chicken populations have experienced
population declines and were nearly extirpated in Colorado, Kansas, and
New Mexico, precisely quantifying the degree to which these settlement-
induced impacts occurred is complicated by a lack of solid and
consistent historical information on lesser prairie-chicken population
size and extent of suitable habitat throughout the species' range.
Additionally, because cultivated grain crops may have provided
increased or more dependable winter food supplies (Braun et al. 1994,
p. 429), the initial conversion of smaller patches of native prairie to
cultivation may have been temporarily beneficial to the short-term
needs of the species. Sharpe (1968, pp. 46-50) believed that the
presence of cultivated grains may have facilitated the temporary
occurrence of lesser prairie-chickens in Nebraska. However, landscapes
having greater than 20 to 37 percent cultivated grains may not support
stable lesser prairie-chicken populations (Crawford and Bolen 1976a, p.
102). While lesser prairie-chickens may forage in agricultural
croplands, they avoid landscapes dominated by cultivated agriculture,
particularly where small grains are not the dominant crop (Crawford and
Bolen 1976a, p. 102). Areas of cropland do not provide adequate year-
round food or cover for lesser prairie-chickens.
Overall, the amount of land used for crop production nationally has
remained relatively stable over the last 100 years although the
distribution and composition have varied (Lubowski et al. 2006, p. 6;
Sylvester et al. 2013, p. 13). As cultivated land is converted to
urbanization and other non-agricultural uses, new land is being brought
into cultivation helping to sustain the relatively constant amount of
cropland in existence over that period. Nationally, the amount of
cropland that was converted to urban uses between 1982 and 1997 was
about 1.5 percent (Lubowski et al. 2006, p. 3). During that same period
nationally, about 24 percent of cultivated cropland was converted to
less intensive uses such as pasture, forest and CRP (Lubowski et al.
2006, p. 3). The impact of CRP was most influential in the Great Plains
States, particularly Colorado, Kansas, Oklahoma and Texas, which have
most of the existing CRP lands (Lubowski et al. 2006, p. 50).
In our June 7, 1998, 12-month finding for the lesser prairie-
chicken (63 FR 31400), we attempted to assess the regional loss of
native rangeland using data available through the National Resources
Inventory of the USDA NRCS. However, very limited information on lesser
prairie-chicken status was available to us prior to 1982. When we
examined the 1992 National Resources Inventory Summary Report, we were
able to estimate the change in rangeland acreage between 1982 and 1992
by each State within the range of the lesser prairie-chicken. When the
trends were examined statewide, each of the five States within the
range of the lesser prairie-chicken showed a decline in the amount of
rangeland acreage over that time period, indicating that conversion of
lesser prairie-chicken habitat likely continued to occur since the
1980s. In assessing the change specifically within areas inhabited by
lesser prairie-chickens, we then narrowed our analysis to just those
counties where lesser prairie-chickens were known to occur. That
analysis, which was based on the information available at that time,
used a much smaller extent of estimated occupied range than likely
occurred at that time. The analysis of the estimate change in rangeland
acreage between 1982 and 1992, for counties specifically within lesser
prairie-chicken range, did not demonstrate a statistically significant
change, possibly due to small sample size and large variation about the
mean. In this analysis, the data for the entire county was used without
restricting the analysis to just those areas determined to be within
the estimated historical and occupied ranges. A more recent, area-
sensitive analysis was needed.
Although a more recent analysis of the Natural Resources Inventory
information was desired, we were unable to obtain specific county-by-
county information because the NRCS no longer releases county-level
information. Release of Natural Resources Inventory results is guided
by NRCS policy and is in accordance with Office of Management and
Budget and USDA Quality of Information Guidelines developed in 2001.
NRCS releases Natural Resources Inventory estimates only when they meet
statistical standards and are scientifically credible in accordance
with these policies. In general, the Natural Resources Inventory survey
system was not developed to provide acceptable estimates for areas as
small as counties but rather for analyses conducted at the national,
regional, and state levels, and for certain sub-state regions (Harper
2012).
We then attempted to use the 1992 National Land Cover Data (NLCD)
information to estimate the extent and change in certain land cover
types. The
[[Page 20025]]
NLCD was the first land-cover mapping project that was national in
scope and is based on images from the Landsat thematic mapper. No other
national land-cover mapping program had previously been undertaken,
despite the availability of Landsat thematic mapper information since
1984. The 1992 NLCD provides information on 21 different land cover
classes at a 30-meter resolution. Based on the 1992 NLCD, and confining
our analysis to just the estimated known historical and occupied
ranges, we estimated that there were 137,073.6 sq km (52,924.4 sq mi)
of cultivated cropland in the entire historical range and 16,436.9 sq
km (6,346.3 sq mi) in the estimated occupied range. Based on these
estimates, 29.35 percent of the estimated historical range is in
cultivated cropland, and 23.28 percent of the estimated occupied range
is in cultivated cropland. This includes areas planted to row crops,
such as corn and cotton, small grains such as wheat and Hordeum vulgare
(barley), and fallow cultivated areas that had visible vegetation at
the time of the imagery.
Estimating the extent of untilled rangeland is slightly more
complicated. The extent of grassland areas dominated by native grasses
and forbs could be determined in a manner similar to that for
cultivated cropland. We estimated from the 1992 NLCD that there were
207,846 sq km (80,250 sq mi) of grassland within the entire historical
range, with only 49,000 sq km (18,919 sq mi) of grassland in the
estimated occupied range. Based on these estimates, 44.51 percent of
the estimated historical range and 69.4 percent of the estimated
occupied range is in grassland cover. However, the extent of shrubland
also must be included in the analysis because areas classified as
shrubland (i.e., areas having a canopy cover of greater than 25
percent) are used by lesser prairie-chicken, such as shinnery oak
grasslands, and also may be grazed by livestock. We estimated that
there were 92,799 sq km (35,830 sq mi) of shrubland within the entire
historical range with 4,439 sq km (1,714 sq mi) of shrubland in the
estimated occupied range, based on the 1992 NLCD. Based on these
estimates, 19.87 percent of the estimated historical range and 6.29
percent of the estimated occupied range is in shrubland.
These values can then be compared with those available through the
2006 NLCD information to provide a rough approximation of the change in
land use since 1992. In contrast to the 1992 NLCD, the 2006 NLCD
provides information on only 16 different land cover classes at a 30-
meter resolution. Based on this dataset, and confining our analysis to
just the known estimated historical and occupied ranges, we estimated
that there were 126,579 sq km (48,872 sq mi) of cultivated cropland in
the entire estimated historical range and 19,588 sq km (7,563 sq mi) in
the estimated occupied range. Based on these results, 27.1 percent of
the estimated historical range and 27.74 percent of the estimated
occupied range is cultivated cropland. This cover type consists of any
areas used annually to produce a crop and includes any land that is
being actively tilled. Estimating the extent of untilled rangeland is
conducted similarly to that for 1992. Using the 2006 NLCD, we estimated
that there were 163,011 sq km (62,939 sq mi) of grassland within the
entire estimated historical range with 42,728 sq km (16,497 sq mi) of
grassland in the estimated occupied range. These results show that
grasslands comprise 34.91 percent of the estimated historical range and
60.52 percent of the estimated occupied range. In 2006, the shrubland
cover type was replaced by a shrub-scrub cover type. This new cover
type was defined as the areas dominated by shrubs less than 5 m (16 ft)
tall with a canopy cover of greater than 20 percent. We estimated that
there were 146,818 sq km (56,686 sq mi) of shrub/scrub within the
entire historical range, with 10,291 sq km (3,973 sq mi) of shrub/scrub
in the estimated occupied range. Based on these results, shrub/scrub
cover constitutes 31.44 percent of the estimated historical range and
14.58 percent of the estimated occupied range.
Despite the difference in the classification of land cover between
1992 and 2006, we were able to make rough comparisons between the two
datasets. The extent of cropland within the entire historical range
declined from 29.35 to 27.1 percent between 1992 and 2006. In contrast,
the extent of cropland areas within the estimated occupied range
increased from 23.28 to 27.74 percent during that same period. A
comparison of the grassland and untilled rangeland indicates that the
amount of grassland declined in both the estimated historical and
occupied ranges between 1992 and 2006. Specifically, the extent of
grassland within the estimated historical range declined from 44.51 to
34.91 percent, and the extent of grassland within the estimated
occupied range declined from 69.4 to 60.52 percent. However, the amount
of shrub-dominated lands increased in both the estimated historical and
occupied ranges. Between 1992 and 2006, the extent of shrubland
increased from 19.87 to 31.44 percent in the estimated historical range
and from 6.29 to 14.58 percent in the estimated occupied range.
Overall, the estimated amount of grassland and shrub-dominated land, as
an indicator of untilled rangelands, increased from 64.38 to 66.34
percent over the estimated historical range during that period but
declined from 75.69 to 75.1 percent within the estimated occupied range
during the same period. Based on the definition of shrub/scrub cover
type in 2006, the observed increases in shrub-dominated cover only
could have been due to increased abundance of eastern red cedar, an
invasive, woody species that tends to decrease suitability of
grasslands and untilled rangelands for lesser prairie-chickens
(Woodward et al. 2001, pp. 270-271; Fuhlendorf et al. 2002a, p. 625).
However, direct comparison between the 1992 and 2006 NLCD is
problematic due to several factors. First, the 1992 NLCD used a
different method to classify habitat than the NLCD 2001 and later
versions. Second, NLCD 2001 and later versions used higher resolution
digital elevation models than the 1992 NLCD. Third, the impervious
surface mapping that is part of NLCD 2001 and later versions resulted
in the identification of many more roads than could be identified in
the 1992 NLCD. However, most of these roads were present in 1992.
Fourth, the imagery for the 2001 NLCD and later versions was corrected
for atmospheric effects prior to classification, whereas NLCD 1992
imagery was not. Lastly, there are subtle differences between the NLCD
1992 and NLCD 2001 land-cover legends. Additionally, we did not have an
estimated occupied range for 1992. Instead we used the occupied range
as is currently estimated. The comparison in the amount of cropland,
grassland, and shrubland could be influenced by a change in the amount
of occupied range in 1992. Due to the influence of CRP grasslands
(discussed below) on the distribution of lesser prairie-chickens in
Kansas, the estimated occupied range was much smaller in 1992. The
Service expects that the influence of CRP establishment north of the
Arkansas River in Kansas might have led to considerably more areas of
grassland in 2006 as compared to 1992. However, the amount of grassland
was observed to have declined within the estimated occupied range of
the lesser prairie-chicken between 1992 and 2006, possibly indicating
that the extent of grasslands continued to decline despite the increase
in CRP grasslands.
If we restrict our analysis to Kansas alone, the extent of
grasslands in 1992 was about 39,381 sq km (15,205 sq mi)
[[Page 20026]]
within the estimated historical range and 22,923 sq km (8850 sq mi) in
the estimated occupied range. In 2006, the extent of grasslands in
Kansas was 27,351 sq km (10,560 sq mi) within the historical range and
18,222 sq km (7,035 sq mi) in the estimated occupied range. While not
definitive, the analysis indicates that the total extent of grasslands
continued to decline even in Kansas where there has been an increase in
CRP grasslands.
Other studies have attempted to determine the change in land use
patterns over time, particularly with respect to conversion of
grasslands/rangelands but such studies are difficult to interpret as
they often do not differentiate between native and non-native
grassland. Additionally, short-term fluctuations in grassland and
cropland acreages often occur at regional levels that may not be
apparent at larger scales and often are not indicative of long-term
changes in land cover. Reeves and Mitchell (2012, p. 14), using USDA
Natural Resources Inventory data, estimated that between 1982 and 2007
non-federal rangelands in the United States, excluding CRP, declined by
about 3.6 million ha (8.8 million ac) or about 142,000 ha (350,000 ac)
annually. More recent data were not available at the time of their
analysis. The estimated losses were largely due to conversion to
cultivated agriculture and residential uses (Reeves and Mitchell 2012,
p. 27). Four of the five States supporting lesser prairie-chicken
populations lost rangeland during this period (Reeves and Mitchell
2012, pp. 15-16). Only Texas had a net gain in the area of rangeland.
New Mexico and Oklahoma lost the most rangeland and Colorado lost the
least. In all four of these States, cropland increased with New Mexico
and Colorado having the largest net change in cropland of the four
States (Reeves and Mitchell 2012, pp. 15-16).
When the historical extent of rangelands were examined in the five
lesser prairie-chicken States, the estimated percentages of historical
rangelands that have been permanently converted to another land use
type break down as follows: 9 percent in New Mexico, 29 percent in
Colorado, 36 percent in Texas, 59 percent in Oklahoma, and 75 percent
in Kansas (Reeves and Mitchell 2012, pp. 26). Although these data are
not specific to the estimated occupied range of the lesser prairie-
chicken, they highlight the extent and types of changes that have
occurred in this region. From a more regional perspective, within the
Great Plains, Sylvester et al. (2013, p.7) concluded that the extent of
grasslands fluctuates considerably as areas alternated between
grassland and cultivation in response to conservation programs, masking
the overall effect on land use change. However, they reported that the
amount of untilled, native grassland, as determined from aerial
photography, continued to decline. Within the Western High Plains
(portions of west Texas, Oklahoma Panhandle, western Kansas, eastern
Colorado and western Nebraska), grassland loss to agriculture,
primarily cropland, was the most common form of land cover conversion
between 1973 and 1986 (Drummond 2007, p 137). Between 1986 and 2000,
grassland cover increased, primarily in response to CRP, but grassland
conversion to agriculture continued to occur. Drummond (2007, p. 138)
estimated 686,000 ha (1.7 million ac) of grassland was converted to
agriculture, primarily cropland, in this region. Increased global
demand for wheat and for irrigated grains to supply local feedlots was
the primary driving factor (Drummond 2007, p 140). Drummond (2007, p.
141) also thought the observed changes in land cover were influenced by
switching of cropland in and out of CRP enrollment. The location of
grasslands changed spatially within the region but there was little
actual overall gain in grassland cover. When conservation programs,
such as cropland retirements, result in no real gain or even a loss in
conservation success, this effect is termed ``slippage'' and will be
discussed further under the section on CRP below.
In summary, conversion of the native grassland habitats used by
lesser prairie-chickens for agricultural uses has resulted in the
permanent, and in some limited instances, temporary loss or alteration
of habitats used for feeding, sheltering, and reproduction.
Consequently, populations of lesser prairie-chickens likely have been
extirpated or significantly reduced, underscoring the degree of impact
that historical conversion of native grasslands has posed to the
species. We expect a very large proportion of the land area that is
currently in cultivated agriculture likely will remain so over the
future because we have no information to suggest that agricultural
practices are likely to change in the future. While persistent drought
and declining supplies of water for irrigation may lead to conversion
of some croplands to a noncropland state, we anticipate that the
majority of cropland will continue to be used to produce a crop.
Groundwater levels in the High Plains Aquifer, which underlies much of
the range of the lesser prairie-chicken and supplies about 30 percent
of the groundwater used for irrigation in the United States
(Sophocleous 2005, p. 352), have declined considerably since the 1950s,
with an area-weighted, average water level decline of 4.3 m (14.2 ft)
(McGuire 2013, pp. 8, 13). Declining water levels may cause some areas
of cropland to revert to grassland but most of the irrigated land
likely will transition to dryland agriculture, in spite of more
efficient methods of irrigation, as water supplies dwindle (Terrell et
al. 2002, p. 35; Sophocleous 2005, p. 361; Drummond 2007, p. 142).
Because much of the suitable arable lands have already been converted
to cultivated agriculture, we do not expect significant additional,
future habitat conversions to cultivated agriculture within the range
of the lesser prairie-chicken. However, as implementation of certain
agricultural conservation programs, such as the CRP, change
programmatically, some continued conversion of grassland, principally
CRP, back into cultivation is still expected to occur (see section
``Conservation Reserve Program'' below). Conservation Reserve Program
contracts, as authorized and outlined by regulation, are of limited,
temporary duration, and the program is subject to funding by Congress.
We also recognize that the historical large-scale conversion of
grasslands to agricultural production has resulted in fragmented
grassland and shrubland habitats used by lesser prairie-chickens such
that currently occupied lands are not adequate to provide for the
conservation of the species into the future, particularly when
cumulatively considering the threats to the lesser prairie-chicken.
Conservation Reserve Program (CRP)
The loss of lesser prairie-chicken habitat due to conversion of
native grasslands to cultivated agriculture has been mitigated
somewhat, at least temporarily, by the CRP. The CRP is a voluntary
program administered by the USDA's FSA and was established primarily to
reduce the production of surplus agricultural commodities and control
soil erosion on certain croplands by converting cropped areas to a
vegetative cover such as perennial grassland. Authorization and
subsequent implementation of the CRP began under the 1985 Food Security
Act and, since that time, has facilitated restoration of millions of
acres of marginal and highly erosive cropland to grassland, shrubland,
and forest habitats (Riffell and Burger 2006, p. 6). Eligibility
criteria for participation in CRP have been established by the FSA and
not all lands are eligible for
[[Page 20027]]
enrollment. Under the general signup process, lands are enrolled in CRP
during designated periods using a competitive selection process.
However, certain environmentally sensitive lands may be enrolled at any
time under a continuous signup provision. The State Acres for Wildlife
Enhancement program, previously discussed in the section highlighting
Multi-State Conservation Efforts, is an example of a continuous signup
program. Additional programs, such as the Conservation Reserve
Enhancement Program and designation as a Conservation Priority Area can
be used to target enrollment of CRP. Participating producers receive an
annual rental payment for the duration of a multiyear CRP contract,
usually 10 to 15 years. Cost sharing is provided to assist in the
establishment of the vegetative cover and related conservation
practices. Once the CRP contract expires, landowners have the option to
either seek reenrollment or exit the program. Once a landowner exits
the program, lands may then be converted back into cropland or other
land use, or remain under a conservation cover. Laycock (1991, p. 4)
believes that retention of the cropland base (base acres that are
enrolled in the FSA program and are used to estimate the amount of
production or dollars that are generated from the land) may be the
single most important factor influencing a landowner's decision to
convert CRP lands to cropland once the contract expires.
In 2009, the enrollment authority or national acreage cap for CRP
was reduced from 15.9 million ha (39.2 million ac) nationwide to 12.9
million ha (32.0 million ac) through fiscal year 2012, with 1.8 million
ha (4.5 million ac) allocated to targeted (continuous) signup programs.
In 2014, the national acreage cap for CRP was reduced from 12.9 million
ha (32.0 million ac) to 9.7 million ha (24 million ac) through fiscal
year 2018. While this does not necessarily require a reduction in CRP
enrollment within the range of the lesser prairie-chicken, it does
indicate that funds available to enroll or reenroll CRP acres likely
will decline over the next 5 years. We assume CRP administration within
the lesser prairie-chicken range will be impacted by the reduction in
funds or acreage caps over the next 5 years. Nationally, the land area
enrolled in CRP has declined since 2006. As of July 2013, approximately
11 million ha (27 million ac) were enrolled in CRP nationwide. Within a
given county, no more than 25 percent of that county's cropland acreage
may be enrolled in CRP and the Wetland Reserve Program. A waiver of
this acreage cap may be granted by the Secretary of Agriculture under
certain circumstances. These caps influence the maximum amounts of
cropland that may exist in CRP at any one time. We are unsure whether
or not waivers of the county acreage cap have been granted within the
estimated occupied range of the lesser prairie-chicken.
Since May of 2003, midcontract management, typically implemented in
years five through seven, has been required on contracts executed since
the summer of 2003 (signup period 26) and is voluntary for contracts
accepted before that time. Mid-contract management practices include
disking, burning, spraying, or interseeding to help establish plants
and to assure an early successful plant growth stage. Typically these
midcontract management activities, including actions such as prescribed
burning, managed grazing, tree thinning, disking, or herbicide
application to control invasive species, are intended to enhance
wildlife benefits and are generally prohibited during the primary avian
nesting and brood rearing season. Within the five States encompassing
the estimated occupied range of the lesser prairie-chicken, the primary
avian nesting and brood rearing season ends no later than July 15th and
varies by State. Under CRP, haying, grazing and several other forms of
limited harvest, including emergency haying and grazing, are authorized
under certain conditions. Managed haying and grazing may be authorized
to improve the quality and performance of the CRP cover. Emergency
haying and grazing may be granted on CRP lands to provide relief to
livestock producers in areas affected by drought or other natural
disaster to minimize loss or culling of livestock herds. In all
instances, participants are assessed a payment reduction based on the
number of acres harvested. Additionally, the installation of wind
turbines, windmills, wind monitoring devices, or other wind-powered
generation equipment may be installed on CRP acreage on a case-by-case
basis. Up to 2 ha (5 ac) of wind turbines per contract may be approved.
Lands enrolled in CRP encompass a significant portion of estimated
occupied range in several lesser prairie-chicken States, but
particularly in Kansas where an increase in the lesser prairie-chicken
population is directly related to the amount of land that was enrolled
in the CRP and planted to mixtures of native grasses. Enrollment
information at the county level is publicly available from the Farm
Service Agency. However, specific locations of individually enrolled
CRP acreages are not publicly available. The Playa Lakes Joint Venture
has an agreement with the Farm Service Agency that allows them to use
available data on individual CRP allotments for conservation purposes,
provided the privacy of the landowner is protected. The Playa Lakes
Joint Venture, using this information, determined the extent of CRP
lands within the estimated occupied range plus a 16-km (10-mi) buffer
(EOR + 10, as defined in the ``Current Range and Distribution''
section, above) (McLachlan et al. 2011, p. 24). In conducting this
analysis, they restricted their analysis to only those lands that were
planted to a grass type of conservation cover and they evaluated all
lands within the estimated occupied range. However, in this study the
estimated occupied range of 65,012 sq km (25,101 sq mi) was based on
the 2007 cooperative mapping efforts conducted by species experts from
CPW, KDWPT, NMDGF, ODWC, and TPWD, in cooperation with the Playa Lakes
Joint Venture; this is a smaller estimated occupied range than is
currently accepted (70,602 sq km (27,259 sq mi)). Based on this
analysis, Kansas was determined to have the most land enrolled in CRP
with a grass cover type. Kansas had approximately 600,000 ha (1,483,027
ac) followed by Texas with an estimated 496,000 ha (1,227,695 ac) of
grassland CRP. Enrolled acreages in Colorado, New Mexico, and Oklahoma
were 193,064 ha (477,071 ac), 153,000 ha (379,356 ac), and 166,000 ha
(410,279 ac), respectively. The amount of grass type CRP within the
study area (EOR + 10) totaled just over 1.61 million ha (3.97 million
ac). Based on the estimated amount of occupied habitat remaining in
these States, CRP fields having a grass type of conservation cover
comprise some 20.6 percent of the estimated occupied lesser prairie-
chicken range in Kansas, 45.8 percent of the estimated occupied range
in Colorado, and 40.9 percent of the estimated occupied range in Texas.
New Mexico and Oklahoma have smaller percentages of CRP within the
occupied range, 17.9 and 15.1 percent, respectively. More recently, the
FSA estimated the current CRP enrollment, as of March of 2013, within
the CHAT EOR + 10 to be 2.05 million ha (5.06 million ac) or about 25
percent of acreage within the CHAT EOR + 10 (FSA 2013, pp. 89, 94).
The importance of CRP acres to the lesser prairie-chicken,
particularly in Kansas, is apparent. Not only do CRP lands constitute
about 25 percent of the
[[Page 20028]]
acreage within the EOR +10 range, about 24 percent of the active lesser
prairie-chicken leks may be found in or in close proximity to lands
enrolled in CRP with another 22 percent of leks located within 1.6 km
(1.0 mi) of CRP lands (FSA 2013, p. 84). The extent of CRP and the
location of active leks serve to highlight the importance of CRP for
lesser prairie-chickens. When the sizes of the CRP fields were
examined, Kansas had 53 percent, on average, of the enrolled lands that
constituted large habitat blocks. A large block was defined as areas
that were at least 2,023 ha (5,000 ac) in size with minimal amounts of
woodland, roads, and developed areas (McLachlan et al. 2011, p. 14).
All of the other States had 15 percent or less of the enrolled CRP in a
large block configuration. The importance of CRP habitat to the status
and survival of lesser prairie-chicken also has been emphasized by
Rodgers and Hoffman (2005, pp. 122-123). They determined that the
presence of CRP lands planted with mixtures of native grasses,
primarily little bluestem, switchgrass, and sideoats grama, facilitated
the expansion of lesser prairie-chicken range in Colorado, Kansas, and
New Mexico. The range expansion was most pronounced in Kansas and
resulted in strong population increases there (Rodgers and Hoffman
2005, pp. 122-123). However, in Oklahoma, Texas, and some portions of
New Mexico, many CRP fields were planted with a monoculture of
introduced grasses. Between 1986 and 1991, 60 percent of the CRP
planted in Oklahoma and 43 percent of the CRP planted in Texas were
planted to introduced grasses (Farm Service Agency 2013, p. 87). Where
introduced grasses were planted, lesser prairie-chickens did not
demonstrate a range expansion or an increase in population size
(Rodgers and Hoffman 2005, p. 123).
An analysis of lesser prairie-chicken habitat quality within a
subsample of 1,019 CRP contracts across all five lesser prairie-chicken
States was recently conducted by the Rocky Mountain Bird Observatory
(Ripper and VerCauteren 2007, entire). They found that, particularly in
Oklahoma and Texas, contracts executed during earlier signup periods
allowed planting of monocultures of exotic grasses, such as
Bothriochloa sp. (old-world bluestem) and Eragrostis curvula (weeping
lovegrass), which provide poor-quality habitat for lesser prairie-
chicken (Ripper and VerCauteren 2007, p. 11). Correspondingly, a high-
priority conservation recommendation from this study intended to
benefit lesser prairie-chickens was to convert existing CRP fields
planted in exotic grasses into fields supporting taller, native grass
species and to enhance the diversity of native forbs and shrubs used
under these contracts. Although lesser prairie-chickens occasionally
will use CRP fields planted to exotic grasses, particularly where
suitable stands of native grasses are unavailable, monoculture stands
of grass generally lack the habitat heterogeneity and structure
preferred by lesser prairie-chickens. Subsequent program adjustments
since 1991 have encouraged the planting of native grass species
mixtures on new CRP enrollments. Expiring CRP fields formerly planted
to monocultures of nonnative, exotic grasses can be reenrolled as
native grass cover, provided at least 51 percent of the field has been
established to a native grass mix. Native grass plantings now account
for well over 80 percent of the cover types established on new CRP
enrollments (Farm Service Agency 2013, p. 87). However, conversion of
fields initially planted to old world bluestems and weeping lovegrass
is difficult considering these species can readily regenerate from seed
following land disturbance (Farm Service Agency 2013, p. 112).
Haying and grazing of CRP lands under both managed and emergency
conditions have the potential to significantly negatively impact
vegetation if the amount of forage removed is excessive and prolonged,
or if livestock numbers are sufficient to contribute to soil
compaction. Currently, managed haying may occur once every three years
in Kansas, Oklahoma, and Texas; once every five years in New Mexico;
and once every ten years in Colorado. Managed grazing frequency is
currently established at once in every three years for Kansas, New
Mexico, Oklahoma and Texas; and once every five years in Colorado.
Older, unexpired contracts may have slightly different restrictions
than those currently described. The FSA estimates that managed haying
and grazing typically occurs on five percent or less of the enrolled
acres within the lesser prairie-chicken range States. Acres subject to
emergency haying and grazing activities are more substantial. The
greatest proportion of emergency hayed or grazed lands in recent years
occurred in 2012 (23 percent), 2011 (21 percent) and 2006 (12.4
percent). Emergency grazing is the predominant use, occurring on over
60 percent of the acres subject to emergency haying and grazing.
Emergency grazing is of far greater concern relative to the lesser
prairie-chicken, specifically considering lesser prairie-chicken
habitat is sensitive to livestock grazing particularly during periods
of drought (Holechek et al. 1982, pp. 206, 208). Additional discussion
related to emergency haying and grazing is provided in the section on
Drought.
Predicting the fate of CRP enrollments and their influence on the
lesser prairie-chicken into the future is difficult. The expiration of
a contract does not automatically trigger a change in land use and
lands likely will continue to be enrolled in the program as long as the
program exists and funds are available to implement the program. The
future of CRP lands is dependent upon three sets of interacting
factors: the long-term economies of livestock and crop production, the
characteristics and attitudes of CRP owners and operators, and the
direct and indirect incentives of existing and future agricultural
policy (Heimlich and Kula 1990, p. 7). As human populations continue to
grow, the worldwide demands for livestock and crop production are
likely to continue to grow. If demand for U.S. wheat and feed grains is
high, pressure to convert CRP lands back to cropland will be strong.
However, in 1990, all five States encompassing the estimated occupied
range of the lesser prairie-chicken were among the top 10 States
expected to retain lands in grass following contract expiration
(Heimlich and Kula 1990, p. 10). A survey of the attitudes of existing
CRP contract holders in Kansas, where much of the existing CRP land
occurs, revealed that slightly over 36 percent of landowners with an
existing contract had made no plans or were uncertain about what they
would do once the CRP contract expired (Diebel et al. 1993, p. 35). An
equal percentage stated that they intended to keep lands in grass for
livestock grazing (Diebel et al. 1993, p. 35). About 24 percent of
enrolled landowners expected they would return to annual crop
production in accordance with existing conservation compliance
provisions (Diebel et al. 1993, p. 35). The participating landowners
stated that market prices for crops and livestock was the most
important factor influencing their decision, with availability of cost
sharing for fencing and water development for livestock also being an
important consideration. However, only a small percentage, about 15
percent, were willing to leave their CRP acreages in permanent cover
after contract expiration where incentives were lacking (Diebel et al.
1993, p. 8).
[[Page 20029]]
Although demand for agricultural commodities and the opinions of
the landowners are important, existing and future agricultural policy
is expected to have the largest influence on the fate of CRP (Heimlich
and Kula 1990, p.10). The CRP was most recently renewed under the
Agricultural Act of 2014, which was signed by the President on February
7, 2014. The Agricultural Act of 2014 provides $5 billion annually in
conservation funding through fiscal year 2018 and extends the CRP
authority through 2018. Because the Agricultural Act of 2014 was just
recently signed into law, the USDA will be responsible for its
implementation, and their next steps include initiation of the rule-
making process for many of the conservation program changes including
those in CRP. Some of the changes in the CRP as a result of enactment
of the new authority include:
The reduction in the acreage cap (as mentioned earlier in
this final rule);
allowance of emergency haying and grazing use without a
penalty in the rental rate paid to the landowner;
allowance of managed haying at least every 5 years but not
more than every 3 years for a 25 percent rental rate reduction;
allowance of routine grazing no more often than once every
2 years;
allowance of wind turbine installation with due
consideration of threatened or endangered wildlife; and
allowance for landowners to make conservation and land
improvements for economic use 1 year before contract expiration.
The FSA anticipates preparation of a supplemental programmatic
environmental impact statement assessing potential changes to the CRP,
including the reduction of the CRP enrollment cap, in 2014 (78 FR
71561).
The possibility exists that escalating grain prices due to the
potential to generate domestic energy from biofuels, such as ethanol
from corn, grain sorghum, and switchgrass, combined with Federal budget
reductions that reduce or eliminate CRP enrollments and renewals, will
result in an unprecedented conversion of existing CRP acreage within
the Great Plains back to cropland (Babcock and Hart 2008, p. 6).
Between 2007 and 2013, Statewide enrollment in CRP within the five
States where lesser prairie-chicken occurs decreased from 4,641,580 ha
(11,469,593 ac) to 3,516,361 ha (8,689,117 ac). This reduction of
1,125,219 ha (2,780,476 ac) not only accounts for lands not re-enrolled
in CRP and loss of lands due to attrition, but also accounts for new
enrolled lands. The most recent CRP general signup for individual
landowners began May 20, 2013, and expired June 14, 2013. Between
September 30, 2013, and October 31, 2013, the FSA reported the net loss
of 142,425 ha (351,939 ac) from CRP in the five States that comprise
the lesser prairie-chicken estimated occupied range; these lands will
be eligible for conversion back to cropland production or other uses in
2014. Of the 358,741 ha (886,468 ac) in the five States that expired
from CRP enrollment on September 30, 2013, 218,162 ha (539,091 ac) were
reenrolled and 140,578 ha (347,375 ac) were not reenrolled. The
opportunity to reenroll or extend existing CRP contracts is generally
based on the relative environmental benefits of each contract. The
Agricultural Act of 2014, however, adds authority for enrollment of
809,371 ha (2 million ac) of working grasslands in CRP, thereby
replacing Grassland Reserve Program contracts. Working grasslands are
defined as grasslands, including improved range or pasturelands, that
contain forbs or shrublands for which grazing is the predominate use.
As part of this change, enrollment priority of working grasslands can
be given to expiring CRP contracts.
Between 2014 and 2018 (the year the CRP authority expires under the
Agricultural Act of 2014), the FSA reports that 743,805 ha (1,837,983
ac) of enrolled CRP lands of all signup types within the five States
where the lesser prairie-chicken occurs will expire. It is not yet
known whether or not these lands will be reenrolled in the program.
More specifically, the FSA estimates that 83, 961 ha (207,471 acres) of
CRP within the EOR + 10 will annually be converted back to cropland
after contract termination (FSA 2013, p. 181). The FSA states that it
intends to enroll an equivalent amount so there is no net loss of
reserved lands. However, the FSA is uncertain as to the likelihood of
maintaining a no net loss of CRP lands.
The history of the Soil Bank Program provides additional insight
into the possible future outcomes of CRP. The Soil Bank Program was
initiated in 1956 as a voluntary program intended to divert land from
crop production by establishing a permanent vegetative cover on the
contracted lands. The contracts ran for periods of three to ten years
and enrollment peaked between 1960 and 1961. At the peak of the program
there were 306,000 farms with about 11.6 million ha (28.7 million ac)
under contract (Laycock 1991, p. 3; Heimlich and Kula, 1991, p. 17).
The Great Plains supported about half of the total acreage where much
of the area was seeded to perennial grasses. By the close of 1969 all
of the contracts had expired and approximately 80 percent of the Soil
Bank lands were back in cultivation by the mid-1970s (Laycock 1991, p.
3; Heimlich and Kula, 1991, p. 17).
Should similar large-scale loss or reductions in CRP acreages
occur, either by reduced enrollments or by conversion back to
cultivation upon expiration of existing contracts, the loss of CRP
acreage would further diminish the amount of suitable lesser prairie-
chicken habitat. This concern is particularly relevant in Kansas where
CRP acreages planted to native grass mixtures facilitated an expansion
of the area estimated to be occupied lesser prairie-chicken range in
that State. In States that planted a predominance of CRP to exotic
grasses, loss of CRP in those States would not be as significant. A
reduction in CRP acreage could lead to contraction of the estimated
occupied range and reduced numbers of lesser prairie-chicken rangewide
and poses a threat to existing lesser prairie-chicken populations.
While the CRP program has had a beneficial effect on the lesser
prairie-chicken by addressing the primary threat of habitat loss and
fragmentation, particularly in Kansas, the contracts are of short
duration (10-15 years) and, given current government efforts to reduce
the Federal budget deficit, additional significant new enrollments in
CRP are not anticipated. However, we anticipate that some CRP grassland
acreages would be reenrolled in the program once contracts expire,
subject to the established acreage cap.
A recent analysis of CRP by the Natural Resources Conservation
Service (Ungerer and Hagen, 2012, pers. comm.) revealed that between
2008 and 2011, approximately 273,160 ha (675,000 ac) of CRP contracts
expired within the estimated occupied range, the majority located in
Kansas. Many of those expired lands remained in grass. Values varied
from a low of 72.4 percent remaining in grass in Colorado to a high of
97.5 percent in New Mexico. Kansas was estimated to have 90.2 percent
of the expired acres during this period still in grass. Values for
Oklahoma and Texas had not yet been determined. We expect that many of
the acreages that remain in grass in New Mexico are likely composed of
exotic species of grasses. Despite a small overall loss in CRP acreage,
we are encouraged by the relatively high percentage of CRP that remains
in grass. However, we remain concerned that the potential for
significant loss of CRP acreages remains, particularly considering the
lack of financial incentive for Kansas landowner and the survey of
[[Page 20030]]
prospective land use changes, as previously discussed above. The
importance of CRP to lesser prairie-chickens, particularly in Kansas,
is high and continued loss of CRP within the estimated occupied range
would be detrimental to lesser prairie-chicken conservation.
We also remain concerned about the future value of these grasslands
to the lesser prairie-chicken. We assume that many of these CRP
grasslands that remain in grass after their contract expires could be
influenced by factors addressed elsewhere in this final rule.
Encroachment by woody vegetation, fencing, wind power development, and
construction of associated transmission lines have the potential to
reduce the value of these areas even if they continue to remain in
grass. Unless specific efforts are made to target enrollment of CRP in
areas important to lesser prairie-chickens, future enrollments likely
will do little to reduce fragmentation or enhance connectivity between
existing populations. Considering much of the existing CRP in Kansas
was identified as supporting large blocks of suitable habitat, as
discussed above, fracturing of these blocks into smaller, less suitable
parcels by the threats identified in this final rule would reduce the
value of these grasslands for lesser prairie-chickens. Additionally,
Fuhlendorf et al. 2002b, p. 405) estimated that cropland areas that
have been restored to native mixed grass prairie may take at least 30
to 50 years to fully recover from the effects of cultivation. The 10-15
year duration of CRP contracts, therefore, may not be long enough to
allow the grasslands to recover from previous cultivation, thereby
calling into question the long-term value of these grasslands for
lesser prairie-chickens.
In summary, we recognize that lands already converted to cultivated
agriculture are located throughout the estimated historical and
occupied range of the lesser prairie-chicken and are, therefore,
perpetuating continuing habitat fragmentation within the range of the
lesser prairie-chicken. We expect that CRP will continue to provide a
means of temporarily addressing this threat by restoring cropland to
grassland cover and provide habitat for lesser prairie-chickens where
planting mixtures and maintenance activities are appropriate. However,
we expect that, in spite of the temporary benefits provided by CRP,
most of the areas already in agricultural production will remain so
into the future. While CRP has contributed to the restoration of
grassland habitats and has influenced abundance and distribution of
lesser prairie-chickens in some areas, we expect these lands to be
subject to conversion back to cropland as economic conditions change in
the future possibly reducing the overall benefit of the CRP to the
lesser prairie-chicken. A similar conservation program, the Soil Bank,
was ineffective in securing permanent gains in grassland acres over the
long term. While we acknowledge the short-term conservation value of
CRP, we do not anticipate that CRP, at current and anticipated funding
levels, will cause significant, permanent increases in the extent of
native grassland within the range of the lesser prairie-chicken
(Coppedge et al. 2001, p. 57; Drummond 2007, p. 142). Consequently, CRP
grasslands alone are not adequate to provide for the long-term
persistence of the species, particularly when the known threats to the
lesser prairie-chicken are considered cumulatively.
Livestock Grazing
Habitats used by the lesser prairie-chicken are naturally dominated
by a diversity of drought-tolerant perennial grasses and shrubs.
Grazing has long been an ecological driving force within the ecosystems
of the Great Plains (Stebbins 1981, p. 84), and much of the untilled
grasslands within the range of the lesser prairie-chicken continue to
be grazed by livestock and other animals. The evolutionary history of
the mixed-grass prairie has produced endemic bird species adapted to an
ever-changing mosaic of lightly to severely grazed grasslands (Bragg
and Steuter 1996, p. 54; Knopf and Samson 1997, pp. 277-279, 283).
Historically the interaction of fire, drought, prairie dogs and large
ungulate grazers created and maintained distinctively different plant
communities in the western Great Plains that resulted in a mosaic of
vegetation structure and composition that sustained lesser prairie-
chickens and other grassland bird populations (Derner et al. 2009, p.
112). As such, grazing by domestic livestock is not inherently
detrimental to lesser prairie-chicken management. For example,
appropriate grazing levels or stocking rates can help ensure grass
cover in brood rearing habitat is not so dense that movements of the
chicks are hindered. However, grazing practices that tend to maximize
livestock weight gain and production produce habitat conditions that
differ in significant ways from the historical mosaic by reducing the
amount of habitat in an ungrazed to lightly grazed condition. The more
heavily altered conditions are less suitable for the lesser prairie-
chicken (Hamerstrom and Hamerstrom 1961, pp. 289-290; Davis et al.
1979, pp. 56, 116; Taylor and Guthery 1980a, p. 2; Bidwell and Peoples
1991, pp. 1-2).
Livestock grazing most clearly affects lesser prairie-chickens when
it alters the composition and structure of mixed-grass habitats used by
the species. Domestic livestock and native ungulates differentially
alter native prairie vegetation, in part through different foraging
preferences (Steuter and Hidinger 1999, pp. 332-333; Towne et al. 2005,
p. 1557). Additionally, domestic livestock grazing, particularly when
confined to small pastures, often is managed in ways that produce more
uniform utilization of forage and greater total utilization of forage,
in comparison to conditions produced historically by free-ranging
plains bison (Bison bison) herds. For example, grazing by domestic
livestock tends to be less patchy, particularly when livestock are
confined to specific pastures, creating a more uniform grass coverage
and height that is not optimal for lesser prairie-chickens. Such
management practices and their consequences may actually exceed the
effect produced by differences in livestock forage preferences (Towne
et al. 2005, p. 1558) but, in any case, produce an additive effect on
plant community characteristics.
The effects of livestock grazing, particularly overgrazing or
overutilization, are most readily observed through changes in plant
community composition and other vegetative characteristics (Fleischner
1994, pp. 630-631; Stoddart et al. 1975, p. 267). Typical vegetative
indicators include changes in the composition and proportion of desired
plant species and overall reductions in forage. Plant height and
density may decline, particularly when plant regeneration is hindered,
and community composition shifts to show increased proportions of less
desirable forage species. Stocking rate and weather account for a
majority of the variability associated with plant and grazing animal
production on rangelands (Briske et al. 2008, p. 8). Stocking rate is a
function of the number of animals being grazed, land area under grazing
management, and time; and, is the most consistent variable land
managers have available to influence plant and animal response to
grazing (Briske et al. 2008, pp. 5-8). Chronic intensive grazing is
detrimental to plants and can be addressed by rest and deferment
(periodic cessation of grazing), particularly during growing season
when plant growth is often rapid. Plants need to recover following
defoliation, including that caused by
[[Page 20031]]
grazing, in order to promote plant growth and sustainability. Low
stocking rates tend to promote plant production while higher stocking
rates reduce plant production by decreasing leaf area per unit ground
area (Briske et al. 2008, pp. 8-9). Excessive stocking rates often are
unsustainable over time (Briske et al. 2008, p. 9).
Grazing management favorable to persistence of the lesser prairie-
chicken must ensure that a diversity of plants and cover types,
including shrubs, remain on the landscape (Taylor and Guthery 1980a, p.
7; Bell 2005, p. 4), and that utilization levels leave sufficient cover
in the spring to ensure that lesser prairie-chicken nests are
adequately concealed from predators (Davis et al. 1979, p. 49; Wisdom
1980, p. 33; Riley et al. 1992, p. 386; Giesen 1994a, p. 98). Under any
grazing regime, the canopy cover of preferred grasses should be at
least 20 to 30 percent with variable grass heights that average no less
than 15 inches (Van Pelt et al. 2013, pp. 75-76). Canopy cover of
shrubs should be between 10 and 50 percent, depending on whether the
dominant shrub is sand sagebrush or shinnery oak and whether the area
is being used for nesting or brood-rearing (Van Pelt et al. 2013, pp.
75-76). Forb cover that exceeds 10 percent is preferred. Utilization
rates (percentage of annual forage production that is harvested by the
grazing livestock) will vary depending on a variety of factors but
should strive to provide vegetative structure that meets the above
criteria. The rangewide plan has more detailed information on
appropriate habitat for lesser prairie-chickens and indicates that
annual utilization rates of 33 percent or less, on average, under
typical range conditions are most beneficial to lesser prairie-chickens
(Van Pelt et al. 2013, pp. 75-76; 150).
Where grazing regimes leave limited residual cover, as described
above, in the spring, protection of lesser prairie-chicken nests may be
inadequate and desirable food plants can be scarce (Bent 1932, p. 280;
Cannon and Knopf 1980, pp. 73-74; Crawford 1980, p. 3). Because lesser
prairie-chickens depend on medium and tall grass species that are
preferentially grazed by cattle, in regions of low rainfall, the
habitat is easily overgrazed in regard to characteristics (i.e. medium
and tall grass species) needed by lesser prairie-chickens (Hamerstrom
and Hamerstrom 1961, p. 290). In addition, when grasslands are in a
deteriorated condition due to overgrazing and overutilization, the
soils have less water-holding capacity, and the availability of
succulent vegetation and insects utilized by lesser prairie-chicken
chicks is reduced. Many effects of overgrazing and overutilization on
habitat quality are similar to effects produced by drought and likely
are exacerbated by actual drought conditions (Davis et al. 1979, p.
122; Merchant 1982, pp. 31-33) (see separate discussion under
``Drought'' in ``Extreme Weather Events'' below).
Fencing is a fundamental tool of livestock management and is often
essential to proper herd management. However, fencing, particularly at
higher densities, can contribute to structural fragmentation of the
landscape and hinder efforts to conserve native grasslands on a
landscape scale (Samson et al. 2004, p. 11-12). Fencing and related
structural fragmentation can be particularly detrimental to the lesser
prairie-chicken in areas, such as western Oklahoma, where initial
settlement patterns favored larger numbers of smaller parcels for
individual settlers (Patten et al. 2005b, p. 245). Fencing large
numbers of small parcels increases the density of fences on the
landscape, increasing opportunities for lesser prairie-chickens to
encounter fences during flight. Fencing not only contributes to direct
mortality through forceful collisions during flight, but also can
indirectly lead to mortality by creating hunting perches used by
raptors and by facilitating corridors that may enhance movements of
mammalian predators (Wolfe et al. 2007, pp. 96-97, 101). In addition,
the presence of fence posts can cause general habitat avoidance and
displacement in lesser prairie-chickens, which is presumably a
behavioral response that serves to limit exposure to predation.
However, not all fences present the same mortality risk to lesser
prairie-chickens. Mortality risk would appear to be dependent on
factors such as fencing design (height, type, number of strands),
landscape topography, and proximity to habitats, particularly leks,
used by lesser prairie-chickens. Other factors such as the length and
density of fences also appear to influence the effects of these
structures on lesser prairie-chickens. However, we are not aware of any
studies on the impacts of different fencing designs and locations with
respect to collision mortality in lesser prairie-chickens. Additional
discussion related to impacts of collisions with fences and similar
linear features are found in the Collision Mortality section below.
Recent rangeland management includes influential elements besides
livestock species selection, grazing levels, and fencing, such as
applications of fire (usually to promote forage quality for livestock)
and water management regimes (usually to provide water supplies for
livestock). Current grazing management strategies are commonly
implemented in ways that are vastly different and less variable than
historical conditions (Knopf and Sampson 1997, pp. 277-79). These
practices have contributed to overall changes in the composition and
structure of mixed-grass habitats, often making them less suitable for
the lesser prairie-chicken. Further, the impacts of grazing are
amplified during drought conditions, which limit the ability of plants
to recover after being grazed by livestock.
Livestock are known to inadvertently flush lesser prairie-chickens
and trample lesser prairie-chicken nests (Toole 2005, p. 27; Pitman et
al. 2006a, pp. 27-29). This can cause direct mortality to lesser
prairie-chicken eggs or chicks or may cause adults to permanently
abandon their nests, again resulting in loss of young. For example,
Pitman et al. (2006a, pp. 27-29) estimated nest loss from trampling by
cattle to be about 1.9 percent of known nests. Additionally, even brief
flushings of adults from nests can expose eggs and chicks to predation
and extreme temperatures. Although documented, the significance of
direct livestock effects on the lesser prairie-chicken is largely
unknown.
Detailed, rangewide information is lacking on the extent,
intensity, and forms of recent grazing, and associated effects on the
lesser prairie-chicken. However, livestock grazing is widespread within
the five lesser prairie-chicken States and occurs over a large portion
of the area currently occupied by lesser prairie-chickens; thus, any
habitat degradation resulting from livestock grazing is likely to
produce population-level impacts on the lesser prairie-chicken. Kansas,
Oklahoma and Texas collectively support 24 percent of all the cattle in
the United States; these three States are also within the top five
States for cattle numbers as of January 2013 (National Agricultural
Statistics Service 2013, p. 5). Where uniform grazing regimes have left
inadequate residual cover in the spring, detrimental effects to lesser
prairie-chicken populations have been observed (Bent 1932, p. 280;
Davis et al. 1979, pp. 56, 116; Cannon and Knopf 1980, pp. 73-74;
Crawford 1980, p. 3; Bidwell and Peoples 1991, pp. 1-2; Riley et al.
1992, p. 387; Giesen 1994a, p. 97). Some studies have shown that
overgrazing in specific portions of the lesser prairie-chicken's
inhabited range has been detrimental to the species. Taylor and Guthery
(1980a, p. 2)
[[Page 20032]]
believed overgrazing explained the demise of the lesser prairie-chicken
in portions of Texas but thought lesser prairie-chickens could maintain
low populations in some areas with high-intensity, long-term grazing.
In New Mexico, Patten et al. (2006, pp. 11, 16) found that grazing did
not have an overall influence on where lesser prairie-chickens occurred
within their study areas, but there was some evidence that the species
did not nest in portions of the study area subjected to cattle grazing.
In some areas within lesser prairie-chicken range, long-term high-
intensity grazing results in reduced availability of lightly grazed
habitat available to support successful nesting (Jackson and DeArment
1963, p. 737; Davis et al. 1979, pp. 56, 116; Taylor and Guthery 1980a,
p. 12; Davies 1992, pp. 8, 13).
In summary, domestic livestock grazing (including management
practices commonly used to benefit livestock production) has altered
the composition and structure of mixed-grass habitats historically used
by the lesser prairie-chicken. Much of the remaining remnants of mixed-
grass prairie and rangeland, while still important to the lesser
prairie-chicken, exhibit conditions quite different from those that
prevailed prior to EuroAmerican settlement. These changes have
considerably reduced the suitability of remnant areas as habitat for
lesser prairie-chickens. Where habitats are no longer suitable for
lesser prairie-chicken, these areas can contribute to fragmentation
within the landscape even though they may remain in native prairie.
Where improper livestock grazing has degraded native grasslands and
shrublands, we do not expect those areas to significantly contribute to
persistence of the lesser prairie-chicken, particularly when considered
cumulatively with the influence of the other known threats. However
livestock grazing is not entirely detrimental to lesser prairie-
chickens, provided grazing management provides habitat that is suitable
for lesser prairie-chickens. When appropriately managed, livestock
grazing can reduce grass density to facilitate movements of broods and
enhance the production and diversity of forbs that provide insects
particularly important to the diet of chicks. Thus, we conclude that
livestock grazing is not a threat if conducted appropriately such that
sufficient residual vegetation remains to provide cover for lesser
prairie-chickens. Negative impacts from livestock grazing are also
usually reversible, unlike many of the other forms of habitat loss and
degradation described herein. Therefore, keeping lands in appropriately
managed rangeland is a key component of lesser prairie chicken
conservation.
Collision Mortality
Wire fencing is ubiquitous throughout the Great Plains as the
primary means of confining livestock to ranches and pastures or
excluding them from areas not intended for grazing, such as CRP lands,
agricultural fields, and public roads. As a result, thousands of miles
of fencing, primarily barbed wire, have been constructed throughout
lesser prairie-chicken range. Like most grassland wildlife throughout
the Great Plains, the lesser prairie-chicken evolved in open habitats
free of vertical structures or flight hazards, such as linear wires.
Until recently, unnatural linear features such as fences, power lines,
and similar wire structures were seldom perceived as a significant
threat at the population level (Wolfe et al. 2007, p. 101). Information
on the influence of vertical structures is provided elsewhere in this
document.
Mortality of prairie grouse caused by collisions with power lines
has been occurring for decades, but the overall extent is largely
unmonitored. Proximity to power lines has been associated with
extirpations of Gunnison and greater sage-grouse due to collisions and
predation (Wisdom et al. 2011, pp. 467-468). Leopold (1933, p. 353)
mentions a two-cable transmission line in Iowa where the landowner
would find as many as a dozen dead or injured greater prairie-chickens
beneath the line annually. Prompted by recent reports of high collision
rates in species of European grouse (Petty 1995, p. 3; Baines and
Summers 1997, p. 941; Bevanger and Broseth 2000, p. 124; Bevanger and
Broseth 2004, p. 72) and seemingly unnatural rates of mortality in some
local populations of lesser prairie-chicken, the Sutton Center began to
investigate collision mortality in lesser prairie-chickens. From 1999
to 2004, researchers recovered 322 carcasses of radio-marked lesser
prairie-chickens in New Mexico, Oklahoma, and portions of the Texas
panhandle. For lesser prairie-chickens in which the cause of death
could be determined, 42 percent of mortality in Oklahoma was
attributable to collisions with fences, power lines, or automobiles. In
New Mexico, only 14 percent of mortality could be traced to collision.
The difference in rates of observed collision between States was
attributed to differences in the amount of fencing on the landscape
resulting from differential land settlement patterns in the two States
(Patten et al. 2005b, p. 245). In Oklahoma, settlement typically
involved smaller areas of land ownership when compared with New Mexico,
leading to a higher density of fences per unit area. Higher density of
fences contributed to the higher collision rates observed in Oklahoma.
With between 14 and 42 percent of adult lesser prairie-chicken
mortality currently attributable to collision with human-induced
structures, Wolfe et al. (2007, p. 101) assert that fence collisions
will negatively influence long-term population viability for lesser
prairie-chickens. Precisely quantifying the scope of the impact of
fence collisions rangewide is difficult due to a lack of relevant
information, such as the extent and density of fencing within the
estimated occupied range. However, we presume that hundreds of miles of
fences are constructed or replaced annually within the estimated
historical and occupied ranges of the lesser prairie-chicken, based on
the extent of livestock grazing within these regions. We presume that
only rarely are old fences (also see discussion in Summary of Ongoing
and Future Conservation Efforts section for more information on fence
removal). While we are unable to quantify the amount of new fencing
being constructed, collision with fences and other linear features,
such as power lines, is likely an important source of mortality for
lesser prairie-chicken, but primarily in localized areas where the
density of these structures on the landscape is high.
Fence collisions are known to be a significant source of mortality
in other grouse. Moss (2001, p. 256) modeled the estimated future
population of capercaille grouse (Tetrao urogallus) in Scotland and
found that, by removing fence collision risks, the entire Scotland
breeding population would consist of 1,300 females instead of 40
females by 2014. Similarly, recent experiments involving fence marking
to increase visibility resulted in a 71 percent overall reduction in
grouse collisions in Scotland (Baines and Andrew 2003, p. 174).
As previously discussed, collision and mortality risk appears to be
dependent on factors such as fencing design (height, type, number of
strands), length, and density, as well as landscape topography and
proximity of fences to habitats used by lesser prairie-chickens.
Although single-strand, electric fences may be a suitable substitute
for multiple strand barbed-wire fences, and possibly lead to reduced
fence collisions, we have no information demonstrating such is the
case. However, marking the top two
[[Page 20033]]
strands of barbed-wire fences increases their visibility and may help
minimize incidence of collision (Wolfe et al. 2009, entire).
In summary, power lines and unmarked wire fences are known to cause
injury and mortality of lesser prairie-chickens, although the specific
rangewide impact on lesser prairie-chickens is largely unquantified.
However, the prevalence of fences and power lines within the species'
range and studies showing significant impacts to other grouse species
suggest these structures may have at least localized, if not
widespread, detrimental effects. While some conservation programs have
emphasized removal of unneeded fences, we conclude that, without
substantially increased removal efforts, a majority of existing fences
will remain on the landscape indefinitely because they are used to
manage livestock grazing on many private lands. Existing fences likely
operate cumulatively with other mechanisms described in this final rule
to diminish the ability of the lesser prairie-chicken to persist,
particularly in areas with a high density of fences.
Shrub Control and Eradication
Shrub control and eradication are additional forms of habitat
alteration that can influence the availability and suitability of
habitat for lesser prairie-chickens (Jackson and DeArment 1963, pp.
736-737). Herbicide applications (primarily 2,4-dichlorophenoxyacetic
acid (2,4-D) and tebuthiuron) to reduce or eliminate shrubs from native
rangelands is a common ranching practice throughout much of lesser
prairie-chicken range, primarily intended to increase forage production
for livestock. Through foliar (2,4-D) or pelleted (tebuthiuron)
applications, these herbicides are designed to suppress or kill, by
repeated defoliation, dicotyledonous plants such as forbs, shrubs, and
trees, while causing no significant damage to monocotyledon plants such
as grasses.
As defined here, shrub control includes efforts that are designed
to have a relatively short-term, temporary effect, generally less than
4 to 5 years, on the target shrub. Eradication consists of efforts
intended to have a more long-term or lasting effect on the target
shrub. Control and eradication efforts have been applied to both
shinnery oak and sand sagebrush dominated habitats, although most shrub
control and eradication efforts are primarily focused on shinnery oak.
The shinnery oak vegetation type is endemic to the southern Great
Plains and is estimated to have historically covered an area of 2.3
million ha (over 5.6 million ac), although its current range has been
considerably reduced through eradication (Mayes et al. 1998, p. 1609).
The distribution of shinnery oak overlaps much of the estimated
occupied lesser prairie-chicken range in New Mexico, southwestern
Oklahoma, and Texas panhandle region (Peterson and Boyd 1998, p. 2).
Sand sagebrush tends to be the dominant shrub in lesser prairie-chicken
range in Kansas and Colorado as well as portions of northwestern
Oklahoma, the northeast Texas panhandle, and northeastern New Mexico.
Control or eradication of sand sagebrush occurs within the lesser
prairie-chicken range (Rodgers and Sexson 1990, p. 494), but the extent
is unknown. Control or eradication of sand sagebrush appears to be more
prevalent in other parts of the western United States. Other species of
shrubs, such as skunkbush sumac or Prunus angustifolia (Chicksaw plum),
also have been the target of treatment efforts. The herbicide 2,4-D has
been commonly used to control sand sagebrush (Thacker et al. 2012. p.
517). Use of 2,4-D in sand sagebrush communities reduced habitat
structure and sand sagebrush density and cover (Thacker et al. 2012. p.
518). Application of this herbicide was not found to increase the
density of perennial forbs or forb species richness (Thacker et al.
2012. p. 518). However annual forb density did increase in pastures
that were treated prior to 1985 where time since treatment allowed
annual forbs to recover post treatment. Typically use of 2,4-D
suppressed sand sagebrush densities for over 20 years, with no increase
in the abundance of grasshoppers, an important food item for lesser
prairie-chickens (Thacker et al. 2012. p. 520). Consequently, Thacker
et al. (2012, p. 521) cautioned against use of 2,4-D for lesser
prairie-chicken habitat management in the absence of research
documenting its impacts on lesser prairie-chicken productivity,
particularly when nesting cover is limited.
Shinnery oak is toxic to cattle when it first produces leaves in
the spring, and it also competes with more palatable grasses and forbs
for water and nutrients (Peterson and Boyd 1998, p. 8), which is why it
is a common target for control and eradication efforts. In areas where
Gossypium spp. (cotton) is grown, shinnery oak was managed to control
boll weevils (Anthonomus grandis), which can destroy cotton crops
(Slosser et al. 1985, entire). Boll weevils overwinter in areas where
large amounts of leaf litter accumulate but tend not to overwinter in
areas where grasses predominate (Slosser et al. 1985, p. 384). Fire is
typically used to remove the leaf litter, and then tebuthiuron, an
herbicide, is used to remove shinnery oak (Plains Cotton Growers 1998,
pp. 2-3). Prior to the late 1990s, approximately 40,469 ha (100,000 ac)
of shinnery oak in New Mexico and 404,685 ha (1,000,000 ac) of shinnery
oak in Texas were lost due to the application of tebuthiuron and other
herbicides for agriculture and range improvement (Peterson and Boyd
1998, p. 2).
Once shinnery oak is eradicated, it is unlikely to recolonize
treated areas. Shinnery oak is a rhizomatous shrub that reproduces very
slowly and does not invade previously unoccupied areas (Dhillion et al.
1994, p. 52). Shinnery oak rhizomes do not appear to be viable in sites
where the plant was previously eradicated, even decades after
treatment. While shinnery oak has been germinated successfully in a
laboratory setting (Pettit 1986, pp. 1, 3), little documentation exists
that shinnery oak acorns successfully germinate in the wild (Wiedeman
1960, p. 22; Dhillion et al. 1994, p. 52). In addition, shinnery oak
produces an acorn crop in only about 3 of every 10 years (Pettit 1986,
p. 1).
While lesser prairie-chickens are found in Colorado and Kansas
where preferred habitats lack shinnery oak, the importance of shinnery
oak as a component of lesser prairie-chicken habitat has been
demonstrated by several studies (Fuhlendorf et al. 2002a, pp. 624-626;
Bell 2005, pp. 15, 19-25). In a study conducted in west Texas, Haukos
and Smith (1989, p. 625) documented strong nesting avoidance by lesser
prairie-chickens of rangelands where shinnery oak had been controlled
with the herbicide tebuthiuron, demonstrating a preference for habitats
with a shinnery oak component. Similar behavior was confirmed by three
recent studies, explained below, in New Mexico examining aspects of
lesser prairie-chicken habitat use, survival, and reproduction relative
to shinnery oak density and herbicide application to control shinnery
oak.
First, Bell (2005, pp. 20-21) documented strong thermal selection
for and dependency of lesser prairie-chicken broods on dominance of
shinnery oak in shrubland habitats. In this study, lesser prairie-
chicken hens and broods used sites within the shinnery oak community
that had a statistically higher percent cover and greater density of
shrubs. Within these sites, microclimate differed statistically between
occupied and random sites, and lesser prairie-chicken survival was
[[Page 20034]]
statistically higher in microhabitat that was cooler, more humid, and
less exposed to the wind. Survivorship was statistically higher for
lesser prairie-chickens that used sites with greater than 20 percent
cover of shrubs than for those choosing 10-20 percent cover; in turn,
survivorship was statistically higher for lesser prairie-chickens
choosing 10-20 percent cover than for those choosing less than 10
percent cover. Similarly, Copelin (1963, p. 42) stated that he believed
the reason lesser prairie-chickens occurred in habitats with shrubby
vegetation was due to the need for summer shade.
In a second study, Johnson et al. (2004, pp. 338-342) observed that
shinnery oak was the most common vegetation type in lesser prairie-
chicken hen home ranges. Hens were detected more often than randomly in
or near pastures that had not been treated to control shinnery oak.
Although hens were detected in both treated and untreated habitats in
this study, 13 of 14 nests were located in untreated pastures, and all
nests were located in areas dominated by shinnery oak. Areas
immediately surrounding nests also had higher shrub composition than
the surrounding pastures. This study suggested that treatment of
shinnery oak can adversely impact nesting by lesser prairie-chickens.
Finally, a third study showed that over the course of four years
and five nesting seasons, lesser prairie-chicken in the core of
estimated occupied range in New Mexico distributed themselves non-
randomly among shinnery oak rangelands treated and untreated with
tebuthiuron (Patten et al. 2005a, pp. 1273-1274). Lesser prairie-
chickens strongly avoided habitat blocks treated with tebuthiuron but
were not statistically influenced by presence of cattle grazing.
Further, herbicide treatment explained nearly 90 percent of the
variation in occurrence among treated and untreated areas. Over time,
radio-collared lesser prairie-chickens spent progressively less time in
treated habitat blocks, with almost no use of treated pastures in the
fourth year following herbicide application (25 percent in 2001, 16
percent in 2002, 3 percent in 2003, and 1 percent in 2004). Although
shinnery oak is an important food source for lesser prairie-chickens,
shinnery oak, particularly in the Southern High Plains, may be more
important for microclimate and thermal regulation than as a food source
(Grisham et al. 2013, entire). Grisham et al. (2013, p. 7) observed
that hens may select shrubby areas over grasses in dry years, possibly
because shrubs, such as shinnery oak, are often the first to leaf out
and are less dependent on short term precipitation, providing suitable
cover for lesser prairie-chicken during short term drought.
In contrast, McCleery et al. (2007, pp. 2135-2136) argued that the
importance of shinnery oak habitats to lesser prairie-chickens has been
overemphasized, primarily based on occurrence of the species in areas
outside of shinnery oak dominated habitats. We agree that shinnery oak
may not be a rigorously required component of lesser prairie-chicken
habitat rangewide. However, we find that shrub cover is an important
component of lesser prairie-chicken habitat, and shinnery oak is a key
shrub in a large portion of the estimated occupied range of the
species. Recently, Timmer (2012, pp. 38, 73-74) found that lesser
prairie-chicken lek density peaked when approximately 50 percent of the
landscape was composed of shrubland patches consisting of shrubs less
than 5 m (16 ft) tall and comprising at least 20 percent of the total
vegetation. Shrubs are an important component of suitable habitat and
where shinnery oak occurs, lesser prairie-chickens use it both for food
and cover. The loss of these habitats likely contributed to observed
population declines in lesser prairie-chickens. Mixed-sand sagebrush
and shinnery oak rangelands are well documented as preferred lesser
prairie-chicken habitat, and long-term stability of shrubland
landscapes has been shown to be particularly important to the species
(Woodward et al. 2001, p. 271).
On BLM-managed lands, where the occurrence of the dunes sagebrush
lizard and lesser prairie-chicken overlaps, their Resource Management
Plan Amendment (RMPA) states that tebuthiuron may only be used in
shinnery oak habitat if there is a 500-m (1,600-ft) buffer around
dunes, and that no chemical treatments should occur in suitable or
occupied dunes sagebrush lizard habitat (BLM 2008, pp. 4-22). In this
RMPA (BLM 2008, pp. 16-17), BLM will allow spraying of shinnery oak in
lesser prairie-chicken habitat where it does not overlap with the dunes
sagebrush lizard. Additionally, the New Mexico State Lands Office and
private land owners continue to use tebuthiuron to remove shinnery oak
for cattle grazing and other agricultural purposes (75 FR 77809,
December 14, 2010). In the past, the NRCS's herbicide spraying program
has treated shinnery oak in at least 39 counties within shinnery oak
habitat (Peterson and Boyd 1998, p. 4). Under the Lesser Prairie-
chicken Initiative, the NRCS may conduct some thinning of shinnery oak
but the specific extent is not enumerated. Thinning of shinnery oak is
addressed under the brush management practice. Total acres estimated to
be treated under the brush management practice in the shinnery oak
ecosystem is 19,230 ha (47,520 ac), however, thinning is expected to be
used only in limited circumstances (Shaughnessy 2013, pp. 50, 54).
The BLM, through the Restore New Mexico program, also treats
mesquite with herbicides to restore grasslands to a more natural
condition by reducing the extent of brush. While some improvement in
livestock forage occurs, the areas are rested from grazing for two
growing seasons and no increase in stocking rate is allowed. Because
mesquite is not readily controlled by fire, herbicides often are
necessary to treat its invasion. The BLM has treated approximately
157,018 ha (388,000 ac) and has plans to treat an additional 140,425 ha
(347,000 ac) (Watts 2014, pers. comm.). In order to treat encroaching
mesquite, BLM aerially treats with a mix of the herbicides Remedy
(triclopyr) and Reclaim (clopyralid). Although these chemicals are used
to treat the adjacent mesquite, some herbicide drift into shinnery oak
habitats can occur during application. Oaks are also included on the
list of plants controlled by Remedy, and one use for the herbicide is
treatment specifically for sand shinnery oak suppression, as noted on
the specimen label (Dow AgroSciences 2008, pp. 5, 7). While Remedy can
be used to suppress shinnery oak, depending on the concentration, the
anticipated impacts of herbicide drift into non-target areas are
expected to be largely short-term due to differences in application
rates necessary for the desired treatments. Forbs are also susceptible
to Remedy, according to the specimen label, and may be impacted by
these treatments, at least temporarily (Dow AgroSciences 2008, p. 2).
Typically, shinnery oak and mesquite occurrences do not overlap.
Shinnery oak typically occurs in areas with sandy soils while mesquite
is more often found in areas where soils have a higher clay content.
Depending on the density of mesquite, these areas may or may not be
used by lesser prairie-chickens prior to treatment.
Lacking germination of shinnery oak acorns, timely recolonization
of treated areas, or any established propagation or restoration method,
the application of tebuthiuron at rates approved for use in most States
can eliminate high-quality lesser prairie-chicken habitat. Large tracts
of shrubland communities are decreasing, and native shrubs drive
reproductive output for ground-nesting
[[Page 20035]]
birds in shinnery oak rangelands (Guthery et al. 2001, p. 116).
In summary, we conclude that the long-term to permanent removal of
native shrubs such as shinnery oak and sand sagebrush is an ongoing
threat to the lesser prairie-chicken throughout the estimated occupied
range, but particularly in New Mexico, Oklahoma, and Texas. Habitat,
which historically included shrubs, in which the shrubs are permanently
removed may fail to continue to meet basic needs of the species, such
as foraging, nesting, predator avoidance, and thermoregulation. Nesting
habitat typically consists primarily of shrubs and native grasses. In
some instances, herbicide use may aid in the restoration of lesser
prairie-chicken habitat, particular where dense monocultures of
shinnery oak may exist. However, long term to permanent conversion of
shinnery oak and sand sagebrush shrubland to other land uses
contributes to habitat fragmentation and poses a threat to population
persistence.
Pesticides
To our knowledge, no studies have been conducted examining
potential effects of agricultural pesticide use on lesser prairie-
chicken populations. However, impacts from pesticides to other prairie
grouse have been documented. Of approximately 200 greater sage grouse
known to be feeding in a block of alfalfa sprayed with dimethoate, 63
were soon found dead, and many others exhibited intoxication and other
negative symptoms (Blus et al. 1989, p. 1139). Because lesser prairie-
chickens are known to selectively feed in alfalfa fields (Hagen et al.
2004, p. 72), we find there may be cause for concern that similar
impacts could occur when pesticides are applied. Additionally some
insect control efforts, such as grasshopper suppression in rangelands
by the USDA Animal and Plant Health Inspection Service, treat
economically damaging infestations of grasshoppers with insecticides.
Treatment could cause reductions in insect populations consumed by
lesser prairie-chickens. However, in the absence of more conclusive
evidence, we do not currently consider application of insecticides for
most agricultural purposes to be a threat to the species.
The use of anticoagulant rodenticides like Rozol[supreg] (active
ingredient-chlorophacinone) that are used to control black-tailed
prairie dogs (Cynomys ludovicianus) also may present a hazard to lesser
prairie-chickens. Lesser prairie-chickens are known to occasionally use
black-tailed prairie dog colonies (Tyler and Shackford 2002, p. 43),
typically as lek sites (NRCS 1999b, p. 3; Bidwell et al. 2002, pp. 1-2,
4; NRCS 2011, p. 3). Application of this rodenticide to control black-
tailed prairie dogs is registered for use in ten States, including the
five States that comprise the estimated occupied range of the lesser
prairie-chicken (Vyas et al. 2013, p. 97). Typical application involves
placement of chorophacinone-treated winter wheat at least 15.24 cm (6
in) inside the burrow from October 1 to March 15th of the following
year (Vyas et al. 2013, pp. 98-99). Application of the bait inside the
burrow would normally make the bait largely unavailable to ground
foraging, granivorous birds, like the lesser prairie-chicken. However
Vyas et al. (2013, p. 100) confirmed that birds can be exposed and
ingest the treated bait, at least in some instances. While they raise
the concern that impacts could occur on a larger scale even when the
rodenticide is applied according to label instructions, the best
available information does not confirm that lesser prairie-chickens or
other western grouse species have been affected by prairie dog control
measures.
Although herbicides are applied within the estimated historical and
occupied ranges, to our knowledge no studies have been conducted
examining potential effects of herbicide use on the health of lesser
prairie-chickens. Typically herbicides are applied as a means of
altering vegetation types or structure and can indirectly alter habitat
used by lesser prairie-chickens. Information on herbicide application
and its effects on lesser prairie-chicken habitat is provided in the
previous section on Shrub Control and Eradication above.
Pesticide application, particularly for agricultural uses, occurs
within both the estimated historical and occupied ranges of the lesser
prairie-chicken. While there are opportunities for individual lesser
prairie-chickens to be exposed to pesticides, we are not aware of any
specific studies addressing the implications of such application on the
individual health of lesser prairie-chickens. In some instances, such
as for grasshopper control programs, pesticide applications have the
potential to reduce food availability for lesser prairie-chickens but
such effects are expected to be localized in nature. While the effects
can be negative, we do not believe this stressor will impact the long
term stability or persistence of the lesser prairie-chicken rangewide
and does not constitute a current threat to the lesser prairie-chicken.
Altered Fire Regimes and Encroachment by Invasive, Woody Plants
Preferred lesser prairie-chicken habitat is characterized by
expansive regions of treeless grasslands interspersed with patches of
small shrubs (Giesen 1998, pp. 3-4). Prior to extensive EuroAmerican
settlement, frequent fires and grazing by large, native ungulates
helped confine trees like Juniperus virginiana (eastern red cedar) to
river and stream drainages and rocky outcroppings. However, settlement
of the southern Great Plains altered the historical disturbance regimes
and contributed to habitat fragmentation and conversion of native
grasslands. The frequency and intensity of these disturbances directly
influenced the ecological processes, biological diversity, and
patchiness typical of Great Plains grassland ecosystems, which evolved
with frequent fire and ungulate herbivory and that provided ideal
habitat for lesser prairie-chickens (Collins 1992, pp. 2003-2005;
Fuhlendorf and Smeins 1999, pp. 732, 737).
Once these historical fire and grazing regimes were altered, the
processes which helped maintain extensive areas of grasslands ceased to
operate effectively. Following EuroAmerican settlement, fire
suppression allowed trees, such as eastern red cedar, to begin invading
or encroaching upon neighboring grasslands. Increasing fire suppression
that accompanied settlement, combined with government programs
promoting eastern red cedar for windbreaks, erosion control, and
wildlife cover, increased availability of eastern red cedar seeds in
grassland areas (Owensby et al. 1973, p. 256, DeSantis et al. 2011, p.
1838). In Oklahoma alone, 1.4 million red cedar seedlings were
estimated to have been planted in 3,058 km (1,900 mi) of shelterbelts
between 1935 and 1942 (DeSantis et al. 2011, p. 1838). Once
established, windbreaks and cedar plantings for erosion control
contributed to fragmentation of the prairie landscape. Because eastern
red cedar is not well adapted to survive most grassland fires due to
its thin bark and shallow roots (Briggs et al. 2002b, p. 290), the lack
of frequent fire greatly facilitated encroachment by eastern red cedar.
Once trees began to invade these formerly treeless prairies, the
resulting habitat became increasingly unsuitable for lesser prairie-
chickens.
Similar to the effects of man-made vertical structures, the
presence of trees causes lesser prairie-chickens to cease using areas
of otherwise suitable habitat. Woodward et al. (2001, pp. 270-271)
[[Page 20036]]
documented a negative association between landscapes with increased
woody cover and lesser prairie-chicken population indices. Similarly,
Fuhlendorf et al. (2002a, entire) examined the effect of landscape
structure and change on population dynamics of lesser prairie-chicken
in western Oklahoma and northern Texas. They found that landscapes with
declining lesser prairie-chicken populations had significantly greater
increases in tree cover types (riparian, windbreaks, and eastern red
cedar encroachment) than landscapes with stable or increasing
(sustained) lesser prairie-chicken populations (Fuhlendorf et al.
2002a, pp. 622, 625).
Tree encroachment into grassland habitats has been occurring for
decades, but the extent has been increasing rapidly in recent years
(Drake and Todd 2002, p. 24; Zhang and Hiziroglu 2010, p. 1033; Ge and
Zou 2013, p. 9094). Based on the estimated rates of encroachment, tree
invasion in native grasslands and rangelands has the potential to
render significant portions of remaining occupied habitat unsuitable
within two to four decades. Once a grassland area has been colonized by
eastern red cedar, the trees are mature within 6 to 7 years and provide
a plentiful source of seed in which adjacent areas can readily become
infested with eastern red cedar. Eastern red cedar cones (fleshy fruit
containing seeds) are readily consumed and dispersed by several species
of migratory and resident birds, many of which favor vertical structure
(Holthuijzen and Sharik 1985, p. 1512, Holthuijzen et al. 1987, p.
1092). Some birds may disperse the seeds considerable distances from
the seed source (Holthuijzen et al. 1987, p. 1094) and passage of the
cones through the digestive tract increased seed germination by 1.5 to
3.5 times (Holthuijzen and Sharik 1985, p. 1512). Despite the
relatively short viability of the seeds, typically only one growing
season, the large cone crop, potentially large seed dispersal ability,
and the physiological adaptations of eastern red cedar to open,
relatively dry sites help make the species a successful invader of
prairie landscapes (Holthuijzen et al. 1987, p. 1094). Most trees are
relatively long-lived species and, once they become established in
grassland areas, will require intensive management to return areas to a
grassland state.
Specific information documenting the extent of eastern red cedar
infestation within the estimated historical and occupied ranges of the
lesser prairie-chicken is limited. Reeves and Mitchell (2012. p. 92)
estimated the percent of non-federal rangeland, by state, where
invasive cedars were present. Although their analysis did not
specifically target the range of the lesser prairie-chicken, the
general scope of the impact of eastern red cedar is apparent. An
estimated 20.4 percent of non-federal rangeland in Oklahoma has eastern
red cedar present. Lesser amounts occur in Kansas (5.1 percent), Texas
(2.6 percent) and Colorado (trace amount). New Mexico was the only
State not currently experiencing encroachment by eastern red cedar.
Additional information from Oklahoma and portions of Kansas also
help demonstrate the significance of this threat to lesser prairie-
chicken habitat. In Riley County, Kansas, within the tallgrass prairie
region known as the Flint Hills, the amount of eastern red cedar
coverage increased over 380 percent within a 21-year period (Price and
Grabow 2010, as cited in Beebe et al. 2010, p. 2). In another portion
of the Flint Hills of Kansas, transition from a tallgrass prairie to a
closed canopy (where tree canopy is dense enough for tree crowns to
fill or nearly fill the canopy layer so that light cannot reach the
floor beneath the trees) eastern red cedar forest occurred in as little
as 40 years (Briggs et al. 2002a, p. 581). Similarly, the potential for
development of a closed canopy (crown closure) in western Oklahoma is
very high (Engle and Kulbeth 1992, p. 304), and eastern red cedar
encroachment in Oklahoma is occurring at comparable rates. Estimates
developed by NRCS in Oklahoma revealed that about 121,406 ha (300,000
ac) a year are being invaded by eastern red cedar (Zhang and Hiziroglu
2010, p. 1033). Stritzke and Bidwell (1989, as cited in Zhang and
Hiziroglu 2010, p. 1033) estimated that the area infested by eastern
red cedar increased from over 600,000 ha (1.5 million ac) in 1950 to
over 1.4 million ha (3.5 million ac) by 1985. By 2002, the NRCS
estimated that eastern red cedar had invaded approximately 3.2 million
ha (8 million ac) of prairie and cross timbers habitat in Oklahoma
(Drake and Todd 2002, p. 24). Zhang and Hiziroglu (2010, p. 1033)
estimated that eastern red cedar encroachment in Oklahoma, based on an
estimated expansion rate of 308 ha (762 ac) per day, is expected to
exceed 5 million ha (12.6 million ac) by 2013 (). At these rates, the
area invaded by eastern red cedar could reach almost 6 million ha (14.5
million ac) by the year 2020 if control efforts are not implemented.
While the area infested by eastern red cedar in Oklahoma is not
restricted to the estimated occupied range of the lesser prairie-
chicken, the problem appears to be the worst in northwestern and
southwestern Oklahoma, which overlaps with the range of the lesser
prairie-chicken (Zhang and Hiziroglu 2010, p. 1032). Considering that
southwestern Kansas and the northeastern Texas panhandle have
comparable rates of precipitation, fire exclusion, and grazing pressure
as western Oklahoma, this rate of infestation is likely occurring in
many areas of the estimated occupied lesser prairie-chicken range.
Ge and Zou (2013, p. 9094) hypothesized that encroachment of
eastern red cedar will be an important factor affecting suitability of
rangelands within the southern Great Plains well into the future. Based
on the observed rate of eastern red cedar expansion in northwestern
Oklahoma between 1965 to 1995, they projected that woody cover would
increase 500 percent by 2015, assuming control efforts are not
implemented. At these rates, eastern red cedar would dominate
approximately 20 percent of a typical landscape. Similar levels of
encroachment are being experienced in Kansas and Texas (Ge and Zou
2013, p. 9094). Schmidt and Wardle (1998, p. 12) predicted that eastern
red cedar expansion in the Great Plains would continue into the future
because of limitations on the use of prescribed fire and the economic
costs of mechanical and chemical treatment of eastern red cedar over
large areas.
Eastern red cedar is not the only woody species known to be
encroaching in prairies used by lesser prairie-chicken. Within the
southern- and western-most portions of the estimated historical and
occupied ranges in eastern New Mexico, western Oklahoma, and the Texas
Panhandle, mesquite is a common woody invader within these grasslands
and can preclude nesting and brood use by lesser prairie-chickens
(Riley 1978, p. vii). Other tall, woody plants, such as Juniperus
pinchotii (redberry or Pinchot juniper), Robinia pseudoacacia (black
locust), Elaeagnus angustifolia (Russian olive), and Ulmus pumila
(Siberian elm) also can be found in prairie habitats historically and
currently used by lesser prairie-chickens and may become invasive in
these areas. For example, in some portions of the Texas panhandle,
Pinchot juniper distribution increased by about 61 percent over a 50
year period (Ansley et al. 1995, p. 50). All of these woody invaders
can provide perch sites for raptors that may prey on lesser prairie-
chickens.
Mesquite is a particularly effective woody invader in grassland
habitats due to its ability to produce abundant, long-lived seeds that
can germinate and
[[Page 20037]]
establish in a variety of soil types and moisture and light regimes
(Archer et al. 1988, p. 123). Much of the remaining grasslands and
rangelands in the southern portions of the Texas panhandle, including
areas within the estimated occupied range, have been invaded by
mesquite. Reeves and Mitchell (2012, p. 92) estimated the percent of
non-federal rangeland in New Mexico, Oklahoma and Texas that has been
invaded by mesquite. Estimates ranged from a low of 7.5 percent in
western Oklahoma to a high of 47.6 percent in Texas. Areas that have
been invaded by mesquite include portions of the estimated occupied
range in these States. Once established, mesquite can alter nutrient
cycles and reduce herbaceous cover (Reeves and Mitchell 2012, p. 99).
Teague et al. (2008, p. 505) reported an average reduction in
herbaceous biomass of 1,400 kg/ha (1247.8 lbs/ac) in areas having 100
percent mesquite cover.
Although the precise extent and rate of mesquite invasion is
difficult to determine rangewide, the ecological process by which
mesquite and related woody species invades these grasslands has been
described by Archer et al. (1988, pp. 111-127) for the Rio Grande
Plains of Texas. In this study, once a single mesquite tree colonized
an area of grassland, this plant acted as the focal point for seed
dispersal of woody species that previously were restricted to other
habitats (Archer et al. 1988, p. 124). Once established, factors such
as overgrazing, reduced fire frequency, and drought interacted to
enable mesquite and other woody plants to increase in density and
stature on grasslands (Archer et al. 1988, p. 112). On their study site
near Alice, Texas, they found that woody plant cover significantly
increased from 16 to 36 percent between 1941 and 1983, likely
facilitated by heavy grazing (Archer et al. 1988, p. 120). The study
site had a history of heavy grazing since the late 1800s. However,
unlike eastern red cedar, mesquite is not as readily controlled by
fire. Wright et al. (1976, pp. 469-471) observed that mesquite
seedlings older than 1.5 years were difficult to control with fire
unless the above ground portions of the trees had first been damaged by
an herbicide application, and the researchers observed that survival of
2- to 3-year-old mesquite seedlings was as high as 80 percent even
following very hot fires.
Prescribed burning is often the best method to control or preclude
tree invasion of native grassland and rangeland. However, burning of
native prairie is often perceived to be destructive to rangelands,
undesirable for optimizing cattle production, and likely to create wind
erosion or ``blowouts'' in sandy soils. Often, prescribed fire is
employed only after significant tree invasion has already occurred and
landowners consider forage production for cattle to have diminished.
Consequently, fire suppression is common, and relatively little
prescribed burning occurs on private land. Additionally, in areas where
grazing pressure is heavy and fuel loads are reduced, a typical
grassland fire may not be intense enough to eradicate eastern red cedar
(Briggs et al. 2002a, p. 585; Briggs et al. 2002b, pp. 293; Bragg and
Hulbert 1976, p. 19). Briggs et al. (2002a, p. 582) found that grazing
reduced potential fuel loads by 33 percent, and the reduction in fuel
load significantly reduced mortality of eastern red cedar post-fire.
While establishment of eastern red cedar reduces the abundance of
herbaceous grassland vegetation, grasslands have a significant capacity
to recover rapidly following cedar control efforts (Pierce and Reich
2010, p. 248). However, both Van Auken (2000, p. 207) and Briggs et al.
(2005, p. 244) stated that expansion of woody vegetation into
grasslands will continue to pose a threat to grasslands well into the
future.
In summary, invasion of native grasslands by certain opportunistic
woody species like eastern red cedar and mesquite cause otherwise
suitable grassland habitats to no longer be used by lesser prairie-
chickens and contribute to fragmentation of native grassland habitats.
Lesser prairie-chickens are grassland obligates and do not thrive in
environments invaded by trees like eastern red cedar and mesquite. We
expect that efforts to control invasive, woody species like eastern red
cedar and mesquite will continue but that treatment efforts likely will
be insufficient to keep pace with rates of expansion, especially when
considering the environmental changes resulting from climate change
(see discussion below). Therefore, encroachment by invasive, woody
plants contributes to further habitat fragmentation and poses a threat
to lesser prairie-chicken population persistence.
Climate Change
The effects of ongoing and projected changes in climate are
appropriate for consideration in our analyses conducted under the Act.
The Intergovernmental Panel on Climate Change (IPCC) has concluded that
warming of the climate in recent decades is unequivocal, as evidenced
by observations of increases in global average air and ocean
temperatures, widespread melting of snow and ice, and rising global sea
level (Solomon et al. 2007, p.1). The term ``climate'', as defined by
the IPCC, refers to the mean and variability of different types of
weather conditions over time, with 30 years being a typical period for
such measurements, although shorter or longer periods also may be used
(IPCC 2007a, p. 78). The IPCC defines the term ``climate change'' to
refer to a change in the mean or variability of one or more measures of
climate (e.g., temperature or precipitation) that persists for an
extended period, typically decades or longer, whether the change is due
to natural variability, human activity, or both (IPCC 2007a, p. 78).
Scientific measurements spanning several decades demonstrate that
changes in climate are occurring and that the rate of change has been
faster since the 1950s. Examples include warming of the global climate
system and substantial increases in precipitation in some regions of
the world and decreases in other regions. (For these and other
examples, see IPCC 2007a, p. 30; and Solomon et al. 2007, pp. 35-54,
82-85). Results of scientific analyses presented by the IPCC show that
most of the observed increase in global average temperature since the
mid-20th century cannot be explained by natural variability in climate,
and is ``very likely'' (defined by the IPCC as 90 percent or higher
probability) due to the observed increase in greenhouse gas
concentrations in the atmosphere as a result of human activities,
particularly carbon dioxide emissions from use of fossil fuels (IPCC
2007a, pp. 5-6 and figures SPM.3 and SPM.4; Solomon et al. 2007, pp.
21-35). Further confirmation of the role of greenhouse gasses comes
from analyses by Huber and Knutti (2011, p. 4), who concluded it is
extremely likely that approximately 75 percent of global warming since
1950 has been caused by human activities.
Scientists use a variety of climate models, which include
consideration of natural processes and variability, as well as various
scenarios of potential levels and timing of greenhouse gas emissions,
to evaluate the causes of changes already observed and to project
future changes in temperature and other climate conditions (e.g., Meehl
et al. 2007, entire; Ganguly et al. 2009, pp. 11555, 15558; Prinn et
al. 2011, pp. 527, 529). All combinations of models and emissions
scenarios yield very similar projections of increases in the most
common measure of climate change, average global surface temperature
(commonly known as global warming), until about 2030. Although
projections of the intensity and rate of warming
[[Page 20038]]
differ after about 2030, the overall trajectory of all the projections
is one of increased global warming through the end of this century,
even for the projections based on scenarios that assume that greenhouse
gas emissions will stabilize or decline. Thus, there is strong
scientific support for projections that warming will continue through
the 21st century and that the extent and rate of change will be
influenced substantially by the extent of greenhouse gas emissions
(IPCC 2007a, pp. 44-45; Meehl et al. 2007, pp. 760-764 and 797-811;
Ganguly et al. 2009, pp. 15555-15558; Prinn et al. 2011, pp. 527, 529).
(See IPCC 2007b, p. 8, for a summary of other global projections of
climate-related changes, such as frequency of heat waves and changes in
precipitation. Also, see IPCC (2012, entire) for a summary of
observations and projections of extreme climate events.)
Various changes in climate may have direct or indirect effects on
species. These effects may be positive, neutral, or negative, and they
may change over time, depending on the species and other relevant
considerations, such as interactions of climate with other variables
(e.g., habitat fragmentation) (IPCC 2007a, pp. 8-14, 18-19).
Identifying likely effects often involves aspects of climate change
vulnerability analysis. Vulnerability refers to the degree to which a
species (or system) is susceptible to, and unable to cope with, adverse
effects of climate change, including climate variability and extremes.
Vulnerability is a function of the type, intensity, and rate of climate
change and variation to which a species is exposed, its sensitivity,
and its adaptive capacity (IPCC 2007a, p. 89; see also Glick et al.
2011, pp. 19-22). There is no single method for conducting such
analyses that applies to all situations (Glick et al. 2011, p. 3). We
use our expert judgment and appropriate analytical approaches to weigh
relevant information, including uncertainty, in our consideration of
various aspects of climate change.
As is the case with all stressors that we assess, even if we
conclude that a species is currently affected or is likely to be
affected in a negative way by one or more climate-related impacts, it
does not necessarily follow that the species meets the definition of an
``endangered species'' or a ``threatened species'' under the Act. If a
species is listed as endangered or threatened, knowledge regarding the
vulnerability of the species to, and known or anticipated impacts from,
climate-associated changes in environmental conditions can be used to
help devise appropriate strategies for its recovery.
Some species of grouse have already exhibited significant and
measurable negative impacts attributed to climate change. For example,
capercaillie grouse in Scotland have been shown to nest earlier than in
historical periods in response to warmer springs yet reared fewer
chicks (Moss et al. 2001, p. 58). The resultant lowered breeding
success as a result of the described climactic change was determined to
be the major cause of the decline of the Scottish capercaillie (Moss et
al. 2001, p. 58).
Within the Great Plains, average temperatures have increased and
projections indicate this trend will continue over this century (Karl
et al. 2009, p. 1). Precipitation within the southern portion of the
Great Plains is expected to decline, with extreme events such as heat
waves, sustained droughts, and heavy rainfall becoming more frequent
(Karl et al. 2009, pp. 1-2). Seager et al. (2007, pp. 1181, 1183-1184)
suggests that `dust bowl' conditions of the 1930s could be the new
climatology of the American Southwest, with future droughts being much
more extreme than most droughts on record.
As a result of changing conditions, the distribution and abundance
of grassland bird species will be affected (Niemuth et al. 2008, p.
220). Warmer air and surface soil temperatures and decreased soil
moisture near nest sites have been correlated with lower survival and
recruitment in some ground-nesting birds such as the bobwhite quail
(Guthery et al. 2001, pp. 113-115) and the lesser prairie-chicken (Bell
2005, pp. 16, 21). On average, lesser prairie-chickens avoid sites that
are hotter, drier, and more exposed to the wind (Patten et al. 2005a,
p. 1275). Specific to lesser prairie-chickens, an increased frequency
of heavy rainfall events could negatively affect their reproductive
success (Lehmann 1941 as cited in Peterson and Silvy 1994, p. 223;
Morrow et al. 1996, p. 599) although the deleterious effects of
increased spring precipitation have been disputed by Peterson and Silvy
(1994, pp. 227-228). Peterson and Silvy (1994, pp. 227-228) concluded
that spring precipitation does not negatively impact annual breeding
success, particularly when the indirect, positive influence of spring
precipitation on nesting and brood rearing habitat is considered.
Additionally, more extreme droughts, in combination with existing
threats, will have detrimental implications for the lesser prairie-
chicken (see Drought discussion in ``Extreme Weather Events'' below).
Boal et al. (2010, p. 4) suggests that increased temperatures, as
projected by climate models, may lead to egg death or nest abandonment
of lesser prairie-chickens. Furthermore, the researchers suggest that
if lesser prairie-chickens shift timing of reproduction (to later in
the year) to compensate for lower precipitation, then temperature
impacts could be exacerbated.
In 2010, we evaluated three different climate change vulnerability
models (U.S. Environmental Protection Agency 2009, draft review;
NatureServe 2010; USDA Rocky Mountain Research Station 2010, in
development) to determine their usefulness as potential tools for
examining the effects of climate change on lesser prairie chickens.
Outcomes from our assessment of each of these models for the lesser
prairie-chicken suggested that the lesser prairie-chicken is highly
vulnerable to, and will be negatively affected by, projected climate
change (Service 2010). Factors identified in the models that increase
the vulnerability of the lesser prairie-chicken to climate change
include, but are not limited to the following: (1) The species' limited
distribution and relatively small declining population, (2) the
species' physiological sensitivity to temperature and precipitation
change, (3) specialized habitat requirements, and (4) the overall
limited ability of the habitats occupied by the species to shift at the
same rate as the species in response to climate change.
Increasing temperatures, declining precipitation, and extended,
severe drought events would be expected to adversely alter habitat
conditions, reproductive success, and survival of the lesser prairie-
chicken. While populations of lesser prairie-chicken in the
southwestern part of the range are likely to be most acutely affected
because this area is expected to see significant changes in temperature
and precipitation (Grisham et al, 2013, entire), populations throughout
the entire estimated occupied range, including Colorado and Kansas,
likely will be impacted as well. The fragmented nature of the estimated
occupied range and habitat losses to date have isolated populations and
will increase their susceptibility to climate change. Based on current
climate change projections of increased temperatures, decreased
rainfall, and an increase of severe events such as drought and rainfall
within the southern Great Plains, the lesser prairie-chicken is likely
to be adversely impacted by the effects of climate changes, especially
when considered in combination with other known threats, such as
habitat loss and fragmentation, and the anticipated vulnerability of
the species.
[[Page 20039]]
Additionally, many climate scientists predict that numerous species
will shift their geographical distributions in response to warming of
the climate (McLaughlin et al. 2002, p. 6070). In mountainous areas,
species may shift their range altitudinally, in flatter areas, ranges
may shift lattitudinally (Peterson 2003, p. 647). Such shifts may
result in localized extinctions over portions of the range, and, in
other portions of their distributions, the occupied range may expand,
depending upon habitat suitability. Changes in geographical
distributions can vary from subtle to more dramatic rearrangements of
occupied areas (Peterson 2003, p. 650). Species occupying flatland
areas such as the Great Plains generally were expected to undergo more
severe range alterations than those in montane areas (Peterson 2003, p.
651). Additionally, populations occurring in fragmented habitats can be
more vulnerable to effects of climate change and other threats,
particularly for species with limited dispersal abilities (McLaughlin
et al. 2002, p. 6074). Species inhabiting relatively flat lands will
require corridors that allow north-south movements, presuming suitable
habitat exists in these areas. Where existing occupied range is bounded
by areas of unsuitable habitat, the species' ability to move into
suitable areas is reduced and the amount of occupied habitat could
shrink accordingly. In some cases, particularly when natural movement
has a high probability of failure, assisted migration may be necessary
to ensure populations persist ((McLachlan et al. 2007, entire).
We do not currently know how the distribution of lesser prairie-
chickens may change geographically under anticipated climate change
scenarios. Certainly the presence of suitable grassland habitats
created under CRP may play a key role in how lesser prairie-chickens
respond to the effects of climate change. Additionally, species that
are insectivorous throughout all or a portion of their life cycle, like
the lesser prairie-chicken, may have increased risks where a
phenological mismatch exists between their biological needs and shifts
in insect abundance due to vulnerability of insects to changes in
thermal regimes (Parmesan 2006, pp. 638, 644, 657; McLachlan et al.
2011, p. 5). McLachlan et al. (2011, pp. 15, 26) predicted that lesser
prairie-chicken carrying capacity would decline over the next 60 years
due to climate change, primarily the result of decreased vegetation
productivity (reduced biomass); however, they could not specifically
quantify the extent of the decline. They estimated the current carrying
capacity within the estimated occupied range to be 49,592 lesser
prairie-chickens (McLachlan et al. 2011, p. 25). Based on their
analysis, McLachlan et al. (2011, p. 29) predicted that the lesser
prairie-chicken may be facing significant challenges to long-term
survival over the next 60 years due to climate-related changes in
native grassland habitat. We anticipate that climate-induced changes in
ecosystems, including grassland ecosystems used by lesser prairie-
chickens, coupled with ongoing habitat loss and fragmentation will
interact in ways that will amplify the individual negative effects of
these and other threats identified in this final rule (Cushman et al.
2010, p. 8).
Extreme Weather Events
Weather-related events such as drought, and snow and hail storms
influence habitat quality or result in direct mortality of lesser
prairie-chicken. Although hail storms typically only have a localized
effect, the effects of snow storms and drought can often be more wide-
spread and can affect considerable portions of the estimated occupied
range.
Drought--Drought is considered a universal ecological driver across
the Great Plains (Knopf 1996, p. 147). Annual precipitation within the
Great Plains is considered highly variable (Wiens 1974a, p. 391) with
prolonged drought capable of causing local extinctions of annual forbs
and grasses within stands of perennial species, and recolonization is
often slow (Tilman and El Haddi 1992, p. 263). Net primary production
in grasslands is strongly influenced by annual precipitation patterns
(Sala et al. 1988, pp. 42-44; Weltzin et al. 2003, p. 944) and drought,
in combination with other factors, is thought to limit the extent of
shrubby vegetation within grasslands (Briggs et al. 2005, p. 245).
Grassland bird species, in particular, are impacted by climate extremes
such as extended drought, which acts as a bottleneck that allows only a
few species to survive through the relatively harsh conditions (Wiens
1974a, pp. 388, 397; Zimmerman 1992, p. 92). Drought also can influence
many of the factors previously addressed in this final rule, such as
exaggerating and prolonging the effect of fires and overgrazing. Seager
et al. (2007, pp. 1181, 1183-1184) suggests that conditions experienced
during the droughts of the 1930s could become more frequent in the
southwestern United States, with future droughts being much more
extreme than most droughts on record.
Drought also may exacerbate the impacts of encroachment of woody
species, such as eastern red cedar and Juniperus pinchotii (redberry or
Pinchot juniper). Eastern red cedar, as previously discussed, and
Pinchot juniper (McPherson et al. 1988, entire) have been rapidly
expanding their range and encroaching into grassland communities due to
lack of fire and other human activities since EuroAmerican settlement.
Pinchot juniper occurs in southwestern Oklahoma through portions of the
Texas panhandle and as far south as the Edwards Plateau in southcentral
Texas (Willson et al. 2008, p. 301). In portions of the Texas
panhandle, the extent of Pinchot juniper increased by about 61 percent
during the period from 1948 to 1982 (Ansley et al. 1995, p. 50) and
encroachment continues to occur although the rate of expansion is not
known. While a lack of moisture does hinder germination of many juniper
species (Smith et al. 1975, p. 126), once established, junipers are
capable of tolerating conditions typical of most droughts. Although
eastern red cedar is one of the least drought tolerant species of
junipers, juniper species as a whole, including those native to North
America, are considered some of the most drought resistant species in
the world (Willson et al. 2008, pp. 299, 303). Increased frequency of
drought, as might occur under a typical climate change scenario, may
slow the initial establishment of eastern red cedar and other junipers
but would not be expected to influence their survival in areas that
have already been invaded. Their observed tolerance to drought
conditions contributes to their ability to invade and multiply, once
established, into more xeric (dry) environments (Willson et al. 2008,
p. 305; DeSantis et al. 2011, p. 1838). Due to their known drought
tolerance and potential for widespread dispersal by birds, we expect
that encroachment by eastern red cedar and other junipers would
continue to occur under anticipated climate change scenarios. Such
drought tolerance may actually enhance their ability to survive under
conditions that are less favorable for other species of plants.
Similarly, we do not anticipate that drought conditions would diminish
the potential for continued expansion of eastern red cedar and other
junipers into regions historically dominated by grasslands.
The Palmer Drought Severity Index (Palmer 1965, entire) is a
measure of the balance between moisture demand (evapotranspiration
driven by temperature) and moisture supply
[[Page 20040]]
(precipitation) and is widely used as an indicator of the intensity of
drought conditions (Alley 1984, entire). This index is standardized
according to local climate (i.e., climate divisions established by the
National Oceanic and Atmospheric Administration) and is most effective
in determining magnitude of long-term drought occurring over several
months. The index uses zero as normal with drought expressed in terms
of negative numbers. Positive numbers imply excess precipitation.
The droughts of the 1930s and 1950s are some of the most severe on
record (Schubert et al. 2004, p. 485). During these periods, the Palmer
Drought Severity Index exceeded negative 4 and 5 in many parts of the
Great Plains, which would be classified as extreme to exceptional
drought. The drought that impacted much of the estimated occupied
lesser prairie-chicken range in 2011 also was classified as severe to
extreme, particularly during the months of May through September
(National Climatic Data Center 2013). This time period is significant
because the period of May through September generally overlaps the
lesser prairie-chicken nesting and brood-rearing season. Review of the
available records for the Palmer Drought Severity Index during the
period from May through September 2011, for the climate divisions that
overlap most of the lesser prairie-chicken estimated occupied range,
revealed that the index exceeded negative 4 in most of the climate
divisions. Climate division 4 in westcentral Kansas was the least
impacted by drought in 2011, with a Palmer Drought Severity Index of
negative 2.37. The most severe drought conditions, based on the Palmer
Index, occurred in the Texas panhandle. Of the eight climate divisions
that encompass the majority of the estimated occupied range, drought
conditions were ranked the worst on record for the entire 118 year
period in four of those climate divisions. Conditions in all but one
climate division were ranked within the ten worst droughts over the
period of record.
Based on an evaluation of the Palmer Drought Severity Index for May
through July of 2012, several of the climate divisions which overlap
the estimated occupied range continued to experience extreme to
exceptional drought. Colorado, New Mexico, and Texas are experiencing
the worst conditions, based on Palmer Index values varying from a low
of negative 6.23 in Colorado to a high index value of negative 4.33 in
Texas and negative 4.51 in New Mexico. Drought conditions were least
severe in Oklahoma, varying from negative 2.15 to negative 4.33. Index
values for Kansas remained in the severe range and were all negative
3.23 or worse.
In 2013, conditions improved slightly in Colorado, Texas, New
Mexico and portions of Oklahoma and Kansas; however, all but two
climate divisions over the majority of the estimated occupied range
were ranked within the top 15 worst droughts on record within those
climate divisions. Although the drought severity index improved across
much of the range, severe drought continued to persist. Persistent
drought conditions, such as those observed between 2011 and 2013 will
impact vegetative cover for nesting and can reduce insect populations
needed by growing chicks. The lesser prairie-chicken estimated
population size in 2013 declined considerably; likely in response to
degraded habitat conditions cause by the drought conditions that
prevailed over most of the estimated occupied range in 2011 and 2012
(see section on ``Recent Population Estimates and Trends'' for
information related to estimated population size). Existing and ongoing
fragmentation of suitable habitat likely contributed to the inability
of lesser prairie-chickens to maintain population numbers in response
to the drought.
Additionally, drought impacts forage needed by livestock and
continued grazing under such conditions can rapidly degrade native
rangeland. During times of severe to extreme drought, suitable
livestock forage may become unavailable or considerably reduced due to
a loss of forage production on existing range and croplands. Through
provisions of the CRP, certain lands under existing CRP contract can be
used for emergency haying and grazing, provided specific conditions are
met, to help relieve the impacts of drought by temporarily providing
livestock forage. Typically, emergency haying and grazing is allowed
only on those lands where appropriate Conservation Practices (CP),
already approved for managed haying and grazing, have been applied to
the CRP field. For example, CRP fields planted to either introduced
grasses (CP-1) or native grasses (CP-2) are eligible. However, during
the widespread, severe drought of 2012 and 2013, eight additional CPs
that were not previously eligible to be hayed or grazed were approved
for emergency haying and grazing only during 2012. These additional CPs
primarily include areas associated with grassed waterways and wetlands.
Areas under CP-25, rare and declining habitats, were included and were
the most valuable to lesser prairie-chickens of the eight additional
practices. Kansas has the most land under CP-25 with about 316,000 ha
(781,000 ac) enrolled statewide.
Typically any approved emergency haying or grazing must occur
outside of the primary nesting season. The duration of the emergency
haying can be no longer than 60 calendar days, and the emergency
grazing period cannot extend beyond 90 calendar days, and both must
conclude by September 30th of the current growing season. Generally
areas that were emergency hayed or grazed in 1 year are not eligible
the following 2 years. Other restrictions also may apply.
In most years, the amounts of land that are emergency hayed or
grazed are low, typically less than 15 percent of eligible acreage,
likely because the producer must take a 25 percent reduction in the
annual rental payment, based on the amount of lands that are hayed or
grazed. However, during the 2011 drought, requests for emergency haying
and grazing were larger than previously experienced. For example, in
Oklahoma, more than 103,200 ha (255,000 ac) or roughly 30 percent of
the available CRP lands statewide were utilized. Within those counties
that encompass the estimated occupied range, almost 55,400 ha (137,000
ac) or roughly 21 percent of the available CRP in those counties were
hayed or grazed. In Kansas, there were almost 95,900 ha (237,000 ac)
under contract for emergency haying or grazing within the estimated
occupied range. The number of contracts for emergency haying and
grazing within the estimated occupied range in Kansas is about 18
percent of the total number of contracts within the estimated occupied
range. Within New Mexico in 2011, there were approximately 21,442 ha
(52,984 ac) under contract for emergency grazing, the entire extent of
which were in counties that are either entirely or partially within the
estimated occupied range of the lesser prairie-chicken. Texas records
do not differentiate between managed CRP grazing and haying and that
conducted under emergency provisions. Within the historical range in
2011, 65 counties had CRP areas that were either hayed or grazed. The
average percent of areas used was 22 percent. Within the counties that
overlap the estimated occupied range, the average percent grazed was
the same, 22 percent.
As of the end of July 2012, the entire estimated occupied and
historical range of the lesser prairie-chicken was classified as
abnormally dry or worse (FSA 2012, p. 14). The abnormally dry category
roughly corresponds to a Palmer Drought Index of minus 1.0 to
[[Page 20041]]
minus 1.9. Based on new provisions announced by USDA on July 23, 2012,
the entire estimated historical and occupied ranges of the lesser
prairie-chicken were eligible for emergency haying and grazing.
Additionally, the reduction in the annual rental payment was reduced
from 25 percent to 10 percent. In 2012, New Mexico did not have any
areas that were under contract for emergency haying or grazing.
Colorado had 1,032 ha (2,550.9 ac) under contract for emergency haying
and 30,030 ha (74,206 ac) under contract for emergency grazing within
the estimated occupied range of the lesser prairie-chicken (Barbarika
2014). In Kansas, about 34,158 ha (84,405 ac) were under contract for
emergency haying and 80,526 ha (198,985 ac) were under contract for
emergency grazing within the estimated occupied range of the lesser
prairie-chicken (Barbarika 2014). In 2012, Oklahoma had about 2,247 ha
(5,552.1 ac) were under contract for emergency haying and 36,736 ha
(90,777.7 ac) were under contract for emergency grazing within the
estimated occupied range (Barbarika 2014). In Texas, about 3,801 ha
(9,392.3 ac) were under contract for emergency haying and 21,950 ha
(54,239.5 ac) were under contract for emergency grazing in 2012 within
the estimated occupied range of the lesser prairie-chicken (Barbarika
2014). Combined, about 41,238 ha (101,900.3 ac) were under contract for
emergency haying and about 169,122 ha (417,908.2 ac) were under
contract for emergency grazing within the estimated occupied range of
the lesser prairie-chicken in 2012 (Barbarika 2014). Although the
extent of emergency haying and grazing that occurred in 2012 represents
only about 3 percent of the total estimated occupied range, the
implications become more significant considering this emergency use
occurs during drought. Under drought conditions, much of the lands that
are not enrolled in CRP are grazed heavily and lands that are enrolled
in CRP represent some of the best remaining habitat under drought
conditions. When these CRP lands are grazed, the effect is to reduce
the amount of usable habitat that is available for lesser prairie-
chicken nesting, brood rearing and thermal regulation. In many
instances, areas that were previously grazed or hayed under the
emergency provisions of 2011 have not recovered due to the influence of
the ongoing drought. Additionally, current provisions will allow
additional fields to be eligible for emergency haying and grazing that
have previously not been eligible, including those classified as rare
and declining habitat (CP-25). Conservation Practice 25 provides for
very specific habitat components beneficial to ground-nesting birds
such as lesser prairie-chickens. The overall extent of relief provided
to landowners could result in more widespread implementation of the
emergency provisions than has been observed in previous years. The FSA
estimated that about 23 percent of the available CRP was emergency
hayed or grazed in 2012 (FSA 2014, p. 60). Widespread haying and
grazing of CRP under drought conditions may compromise the ability of
these grasslands to provide year-round escape cover and thermal cover
during winter, at least until normal precipitation patterns return (see
sections Summary of Ongoing and Future Conservation Actions and
``Conservation Reserve Program'' for additional information related to
CRP).
Although the lesser prairie-chicken has adapted to drought as a
component of its environment, drought and the accompanying harsh,
fluctuating conditions have influenced lesser prairie-chicken
populations. Following extreme droughts of the 1930s and 1950s, lesser
prairie-chicken population levels declined and a decrease in their
overall range was observed (Lee 1950, p. 475; Schwilling 1955, pp. 5-6;
Hamerstrom and Hamerstrom 1961, p. 289; Copelin 1963, p. 49; Crawford
1980, pp. 2-5; Massey 2001, pp. 5, 12; Hagen and Giessen 2005,
unpaginated; Ligon 1953 as cited in New Mexico Lesser Prairie Chicken/
Sand Dune Lizard Working Group 2005, p. 19). A reduction in lesser
prairie-chicken population numbers was documented after drought
conditions in 2006 followed by severe winter conditions in 2006 and
early 2007. For example, Rodgers (2007b, p. 3) determined that the
estimated number of lesser prairie-chickens per unit area, based on lek
surveys conducted in Hamilton County, Kansas, declined by nearly 70
percent from 2006 levels and were the lowest on record at that time. In
comparison to the 2011 and 2012 drought, the Palmer Drought Severity
Index for the May through September period in Kansas during the 2006
drought was minus 2.83 in climate division 4 and minus 1.52 in climate
division 7. Based on the Palmer Drought Severity Index, drought
conditions from 2011to 2013 were much more severe than those observed
in 2006. The National Weather Service Climate Prediction Center (2014)
predicts that through the end of April 2014, drought conditions will
persist or intensify over the entire estimated occupied range. Unless
the outlook changes, we anticipate that drought conditions will again
adversely impact habitat during the nesting and brood rearing season.
Such impacts will reduce nesting success and recruitment well into
2014.
Drought impacts the lesser prairie-chicken through several
mechanisms. Drought affects seasonal growth of vegetation necessary to
provide suitable nesting and roosting cover, food, and opportunity for
escape from predators (Copelin 1963, pp. 37, 42; Merchant 1982, pp. 19,
25, 51; Applegate and Riley 1998, p. 15; Peterson and Silvy 1994, p.
228; Morrow et al. 1996, pp. 596-597). Lesser prairie-chicken home
ranges will temporarily expand during drought years (Copelin 1963, p.
37; Merchant 1982, p. 39) to compensate for scarcity in available
resources. During these periods, the adult birds expend more energy
searching for food and tend to move into areas with limited cover in
order to forage, leaving them more vulnerable to predation and heat
stress (Merchant 1982, pp. 34-35; Flanders-Wanner et al. 2004, p. 31).
Chick survival and recruitment may also be depressed by drought
(Merchant 1982, pp. 43-48; Morrow 1986, p. 597; Giesen 1998, p. 11;
Massey 2001, p. 12), which likely affects population trends more than
annual changes in adult survival (Hagen 2003, pp. 176-177). Drought-
induced mechanisms affecting recruitment include decreased
physiological condition of breeding females (Merchant 1982, p. 45);
heat stress and water loss of chicks (Merchant 1982, p. 46); and
effects to hatch success and juvenile survival due to changes in
microclimate, temperature, and humidity (Patten et al. 2005a, pp. 1274-
1275; Bell 2005, pp. 20-21; Boal et al. 2010, p. 11). Precipitation, or
lack thereof, appears to affect lesser prairie-chicken adult population
trends with a potential lag effect (Giesen 2000, p. 145). That is, rain
in one year promotes more vegetative cover for eggs and chicks in the
following year, which enhances their survival.
Although lesser prairie-chickens have persisted through droughts in
the past, the effects of such droughts are exacerbated by 19th-21st
century land use practices such as heavy grazing, overutilization, and
land cultivation (Merchant 1982, p. 51; Hamerstrom and Hamerstrom 1961,
pp. 288-289; Davis et al. 1979, p. 122; Taylor and Guthery 1980a, p.
2), which have altered and fragmented existing habitats. In past
decades, fragmentation of lesser prairie-chicken habitat likely was
less extensive than current conditions, and connectivity between
occupied habitats
[[Page 20042]]
was more prevalent, allowing populations to recover more quickly. As
lesser prairie-chicken populations decline and become more fragmented,
their ability to rebound from prolonged drought is diminished. This
reduced ability to recover from drought is particularly concerning
given that future climate projections suggest that droughts will only
become more severe. Projections based on an analysis using 19 different
climate models revealed that southwestern North America, including the
entire estimated historical and occupied range of the lesser prairie-
chicken, will consistently become drier throughout the 21st century
(Seager et al. 2007, p. 1181). Severe droughts should continue into the
future, particularly during persistent La Ni[ntilde]a events, but they
are anticipated to be more severe than most droughts on record (Seager
et al. 2007, pp. 1182-1183).
Grisham et al. (2013, entire) recently evaluated the influence of
drought and projected climate change on reproductive ecology of the
lesser prairie-chicken in the Southern High Plains (eastern New Mexico
and Texas panhandle). They predicted that average daily survival would
decrease dramatically under all climatic scenarios they examined. Nest
survival from onset of incubation through hatching were predicted to be
less than or equal to 10 percent in this region within 40 years.
Modeling results indicated that nest survival would fall well below the
threshold for population persistence during that time (Grisham et al.
2013, p. 8). Although estimates of persistence of lesser prairie-
chickens provided by Garton (2012, pp. 15-16) indicated that lesser
prairie-chickens in the Shinnery Oak Prairie Region (New Mexico and
Texas) had a relatively high likelihood of persisting over the next 30
years, he only examined current information and did not fully consider
the implications of projected impacts of climate change in his
analysis. Climate change projections provided by Grisham et al. (2013,
p.8) indicate that the prognosis for persistence of lesser prairie-
chickens within this isolated region on the southwestern periphery of
the range is considerably worse than previously predicted under
projected climate change scenarios.
Storms--Very little published information is available on the
effects of certain isolated weather events, like storms, on lesser
prairie-chicken. However, hail storms are known to cause mortality of
prairie grouse, particularly during the spring nesting season. Fleharty
(1995, p. 241) provides an excerpt from the May 1879 Stockton News that
describes a large hailstorm near Kirwin, Kansas, as responsible for
killing prairie-chickens (likely greater prairie-chicken) and other
birds by the hundreds. In May of 2008, a hailstorm killed six lesser
prairie-chickens in New Mexico (Beauprez 2009, p. 17; Service 2009, p.
41). Although such phenomena are undoubtedly rare, the effects can be
significant, particularly if they occur during the nesting period.
A severe winter snowstorm in 2006, centered over southeastern
Colorado, resulted in heavy snowfall, no cover, and little food in
southern Kiowa, Prowers, and most of Baca Counties for over 60 days.
The storm was so severe that more than 10,000 cattle died in Colorado
alone from this event, in spite of the efforts of National Guard and
other flight missions that used cargo planes and helicopters to drop
hay to stranded cattle (Che et al. 2008, pp. 2, 6). Lesser prairie-
chicken numbers in Colorado experienced a 75 percent decline from 2006
to 2007, from 296 birds observed to only 74. Active leks also declined
from 34 leks in 2006 to 18 leks in 2007 (Verquer 2007, p. 2). Most
strikingly, no active leks have been detected since 2008 in Kiowa
County, which had six active leks in the several years prior to the
storm. The impacts of the severe winter weather, coupled with drought
conditions observed in 2006, probably account for the decline in the
number of lesser prairie-chickens observed in 2007 in Colorado (Verquer
2007, pp. 2-3). Birds continued to slowly recover following this storm
event, with numbers peaking in 2011 (Smith 2013, p.3). Since 2011,
numbers of birds have declined and are just slightly above numbers
reported in 2007.
In summary, extreme weather events can have a significant impact on
individual populations of lesser prairie-chickens. While improving
habitat quality and quantity can help stabilize grouse populations and
enhance resiliency, it has little influence on stochastic processes
like drought and hailstorms that can lead to extinction in local
populations (Silvy et al. 2004, p. 19). Extreme weather events will
continue to occur, as they have in the past, and only where lesser
prairie-chickens populations are sufficiently resilient can they be
expected to persist. The impact of extreme weather events is especially
significant in considering the status of the species as a whole if the
impacted population is isolated from individuals in other nearby
populations that may be capable of recolonizing or supplementing the
impacted population. Droughts, severe storms and other extreme weather
events, although recurring, are unpredictable and little can be done to
alter or control the occurrence or significance of these events. Such
events, and the anticipated impacts, are expected to continue to occur
into the future. Drought, in particular, may occur throughout the range
of the species, as it did in 2011, 2012, and 2013, and can severely
impact persistence of the lesser prairie-chicken. In particular, the
persistence of the lesser prairie-chicken in the southwestern portions
of the estimated occupied range (New Mexico and Texas) appears to be
highly unlikely over the next 30 to 40 years, particularly considering
the implications of climate change and recurring droughts (Grisham et
al. (2013, entire). Loss of these populations would exacerbate the
ongoing reduction in occupied range that has been evident over the past
century. Extreme weather events, principally drought, are a threat to
the lesser prairie-chicken, particularly when considered in light of
other threats such as habitat loss, fragmentation and climate change,
that reduce resiliency of the species.
Influence of Noise
The timing of displays and frequency of vocalizations in lesser
prairie-chickens and other prairie grouse appear to have developed in
response to conditions prevalent in prairie habitats and indicates that
effective communication, particularly during the lekking season,
operates within a fairly narrow set of conditions. Grasslands are
considered poor environments for sound transmission because absorption
by vegetation and the ground, combined with scattering caused by high
winds and thermal turbulence causes the sound intensity to diminish
(attenuate) rapidly (Morton 1975, pp. 17, 28; Sparling 1983, p. 40). In
a response to this excess attenuation, grassland birds would have to
evolve mechanisms that counteract this attenuation in order to
communicate effectively over long distances. One primary means of
overcoming this barrier would be to produce vocalizations with low
carrier frequencies (Sparling 1983, p. 40), as is common in prairie
grouse. Activity patterns also may play an important role in
facilitating communication in grassland environments (Morton 1975, p.
30). Prairie grouse usually initiate displays on the lekking grounds
around sunrise, and occasionally near sunset, corresponding with times
of decreased wind and thermal turbulence (Sparling 1983, p. 41).
Considering the narrow set of conditions in which communication appears
most effective for breeding lesser prairie-chickens, and the
[[Page 20043]]
importance of communication to successful reproduction, activities that
disrupt or alter these conditions likely will have a negative impact on
reproductive potential and population growth.
While human activities, such as livestock management, grassland
restoration, shrub control and pesticide application, as discussed in
the sections above, all cause varying degrees of noise, the impacts of
noise on lesser prairie-chickens is more readily apparent and often
most persistent (chronic) when it occurs in association with placement
of human infrastructure, as discussed in several of the sections below.
Almost any anthropogenic feature or related activity that occurs on the
landscape can create noise that exceeds the natural background or
ambient level. Expansion of transportation networks, urban/suburban
development, mineral and other forms of resource extraction and
motorized recreation are responsible for most chronic noise exposure in
terrestrial environments (Barber et al. 2009, p. 1980). In terrestrial
systems, the impact of noise may manifest itself in modified behavioral
response, physiological stress, and various impacts on communication
(Barber et al. 2009, p. 181). Noise that results in either
physiological stress or impacts communication is likely to then cause a
behavioral response. When the behavioral response to noise is
avoidance, as it often is for lesser prairie-chickens and other prairie
grouse, noise can be a major source of habitat loss or degradation and
lead to increased habitat fragmentation.
Several studies have examined the effect of noise on greater sage-
grouse. Crompton (2005, p. 10) monitored the installation of a well pad
in Utah that was placed within 200 m (656 ft) of a greater sage-grouse
lek during 2001. When construction was complete and the pumping unit
was operating, noise levels recorded 20 m (66 ft) from the pumping unit
were 70 dB and had dropped to 45 dB when measured 200 m (656 ft) from
the pumping unit (Crompton 2005, p. 10). Attendance of males at this
lek declined dramatically beginning with installation of the well pad
and the lek was completely abandoned within 2 years. The following
year, the pumping unit was shut down for repairs during April and
grouse briefly recolonized the lek. Overall, male lek attendance
declined by 44 percent in areas that were developed for coalbed methane
production compared with a 15 percent increase in male lek attendance
in undeveloped areas (Crompton 2005, p. 10). Annual survival rates for
females also were much lower (12.5 percent) in areas developed for
coalbed methane than in undeveloped areas (73 percent) (Crompton 2005,
p. 19). Consequently, Crompton (2005, p. 22) recommended that noise
levels at active leks should be less than 40 dB and no well pad should
be located within 1,500 m (0.93 mi) of an active lek. Sound muffling
devices were recommended for all existing wells that were within this
1,500 m (0.93 mi) buffer.
Blickley et al. (2012a, entire) examined the impact of chronic
noise on greater sage-grouse using playback experiments. This study was
accomplished by recording noise associated with natural gas drilling
rigs and the traffic associated with gas-field roads and then re-
playing these recordings near leks. Their results suggest that chronic
noise had a negative impact on lek attendance by male greater sage-
grouse. Peak male attendance decreased by 73 percent at leks exposed to
road noise and 29 percent at leks exposed to noise from gas drilling
activity, when compared to paired control leks (Blickley et al. 2012a,
p. 467). The observed decrease in lek attendance was immediate and
sustained throughout the study, although modeling suggested that
attendance at the leks rebounded once the noise ceased (Blickley et al.
2012a, p. 467). Because the sound volume of the recorded playback was
not loud enough to cause direct injury, they concluded that the sounds
caused displacement of the males that would normally have attended the
leks (Blickley et al. 2012a, p. 468). Although higher mortality caused
by increased predation was another possible mechanism for the observed
decreases in lek attendance, they did not consider increased predation
to be a factor due to low observations of predation events at the leks
and because predation would result in a gradual decrease in attendance
rather than the rapid and sustained decline they observed (Blickley et
al. 2012a, p. 467). Displacement was likely the result of masking of
the male's vocalizations at the lek, reducing ability of females to
detect acoustic cues and locate leks in noisy areas (Blickley et al.
2012a, p. 469).
Related work by Blickley and Patricelli (2012, entire) examined the
potential for noise to mask the sounds used by greater sage-grouse
during communication. They stated that most anthropogenic noise is
dominated by low frequencies and that birds, such as greater sage-
grouse, that produce vocalizations dominated by low frequencies will
disproportionately have their vocalizations masked by these
developments (Blickley and Patricelli 2012, p. 31). Measurements were
taken at various noise sources typically associated with oil and gas
operations, including a compressor station, a deep natural gas drilling
rig, and at a diesel powered generator (Blickley and Patricelli 2012,
p. 27). They also measured the ambient noise associated with an
undisturbed lek after lekking had ceased in the morning and expressed
the noise produced by each source in relation to the ambient noise
levels at various distances. All sounds were recorded at a height of 25
cm (10 in) which roughly corresponds to the height of a typical grouse
(Blickley and Patricelli 2012, p. 27). Noise produced by the compressor
was 48.9 dB higher than ambient levels at a distance of 75 m (246 ft)
from the source and 34.2 dB higher at 400 m (1,312 ft) from the source
(Blickley and Patricelli 2012, p. 28). Noise produced by the drilling
rig was slightly less than these values at the same distances and noise
produced by the generator was 24.9 dB and 18.4 dB higher than ambient
levels at these distances. Butler et al. (2010. pp. 1160-1161) observed
the intensity of booming in lekking lesser prairie-chickens and
estimated that sound intensity of booming vocalizations would be less
than or equal to 60 dB at 21 m (69 ft), less than or equal to 30 dB at
645 m (2,116 ft) and about 22 dB at 1.6 km (5,240 ft).
The frequency of the sounds produced by these sources at these same
distances was 8 kilohertz (kHz) or less. The variety of vocalizations
produced by greater sage-grouse peaked at 11.5 kHz or less (Blickley
and Patricelli 2012, p. 29). Based on this study, noise produced by
typical oil and gas infrastructure can mask grouse vocalizations and
compromise the ability of female greater sage-grouse to find active
leks when such noise is present (Blickley and Patricelli 2012, p. 32).
Although female grouse also use visual cues to assess potential mates
on a lek, noisy leks can cause female attendance at these leks to
decline. As previously discussed in this section, chronic noise
associated with human activity also leads to reduced male attendance at
noisy leks. While the effects of masking will decline with distance
from the sound source, other communication used by grouse off the lek,
such as parent-offspring communication, may continue to be susceptible
to masking by noise from human infrastructure (Blickley and Patricelli
2012, p. 33). These findings
[[Page 20044]]
are particularly important in assessing the impacts of development on
grouse activity, especially considering that females use the sounds
produced by the males during courtship to locate a lek, then once a lek
has been located, to select a mate from the males displaying on that
lek. Breeding, reproductive success and ultimately recruitment in areas
with human developments could be impaired by inappropriate placement of
such developments, impacting survival. Additionally behavioral
responses exhibited by grouse when exposed to chronic noise could lead
to reductions in the amount of suitable habitat and negatively
influence survival and population size in such areas.
During related studies, Blickley et al. (2012b, entire) evaluated
the implications of chronic noise on the physiological health of
lekking male greater sage-grouse through the assessment of
glucocorticoid hormone levels. Glucocorticoid hormones are secreted
into the blood in response to stress and their metabolites can be
measured in fecal samples as an indication of the stress response. In
this study, noise associated with roads and drilling activity, as
described in Blickley et al. (2012a, pp. 464-466), was recorded and
replayed at active greater sage-grouse leks. Males exposed to chronic
noise had higher (16.7 percent, on average) fecal levels of
immunoreactive corticosteroid metabolites than did males from
undisturbed leks, confirming chronic noise increased stress levels in
male sage grouse that remained on the noisy leks (Blickley et al.
2012b, pp. 4-5). However, there was little difference in male response
in relation to the type (e.g., road or drilling) of noise. Chronic
noise created less desirable habitat for greater sage-grouse than
habitat present at undisturbed locations, at least at breeding sites
(Blickley et al. 2012b, p. 6). The impacts of chronic noise on stress
levels in wintering, nesting, and for foraging males are unknown. Noise
is likely perceived as a threat by greater sage-grouse and may impact
social interactions, including territorial response and recognition of
other greater sage grouse (conspecifics), feeding activities and
responses to predation, particularly if alarm calls are masked by noise
(Blickley et al. 2012b, p. 6). Chronic noise may not only reduce the
amount of useable space but chronic physiological stress could
potentially affect overall health of the organism including disease
resistance, survival, and reproductive success.
We anticipate similar behavioral responses by lesser prairie-
chickens because their vocalizations are low frequency and vocalization
intensity is less than or equal to sound intensity produced by many
man-made developments. Blickley et al. (2012a, p. 470) believed that
noise may be a possible factor in the population declines of other
species of lekking grouse in North America, particularly for
populations that are exposed to human developments. Like sage grouse,
lesser prairie-chicken vocalizations are low frequency, generally less
than 4 kHz (Sharpe 1968, p. 111-146; Hagen and Giesen 2005,
unpaginated), and subject to being masked by noise from human
developments. Butler et al. (2010, p. 1161) predicted sound intensity
of lesser prairie-chicken booming vocalizations would be 60 dB or less
at 21 m (69 ft) and 30 dB or less at 645 m (2,116 ft) from the lek.
Hunt (2004, p. 141) measured sound levels at 33 active and 39
abandoned lesser prairie-chicken leks in New Mexico in an attempt to
determine the relationship between noise levels and lek activity. Noise
levels from several types of infrastructure associated with oil and gas
drilling operations were measured (Hunt 2004, pp. 147-148). Average
noise levels of drilling rigs at a distance of 320 m (1,050 ft) was 24
dB above ambient levels measured at active leks and average noise
levels for propane and electric powered pumping units at this same
distance were 14 and 5.9 dB higher, respectively, than ambient levels
at active leks. Although ambient noise levels at abandoned leks were
significantly higher (average difference was 4 dB) than ambient noise
levels at active leks, he concluded that the observed difference did
not, by itself, completely explain why the leks were abandoned (Hunt
2004, p. 142). Other factors associated with petroleum development,
such as human activity, presence of power lines and road density,
likely contributed to abandonment of the leks they observed (Hunt 2004,
p. 142). Abandoned leks had more active wells, more total wells, and
greater length of road than active leks, and were more likely than
active leks to be near power lines (Hunt 2004, p. iv).
Pitman et al. (2005, p. 1264) observed the behavioral responses of
nesting lesser prairie-chicken hens to the presence of anthropogenic
features, such as wellheads, buildings, roads, transmission lines, and
center-pivot irrigation fields, in southwestern Kansas. They reported
that the presence of anthropogenic features resulted in the avoidance
of 7,114 ha (17,579 ac) of the 13,380 ha (33,063 ac) of nesting habitat
available within their study area and concluded that noise associated
with these features likely contributed to the behavioral response
exhibited by the nesting hens (Pitman et al. 2005, p. 1267). They also
noted that sound levels, as measured 100 m (328 ft) from the source,
ranged from 60-80 dB for center-pivots, 80-100 dB for compressor
stations, and over 100 dB for a power plant. Additionally noise
associated with transmission lines and heavy traffic from improved
roads was audible at a distance over 2 km (1.2 mi) from the source.
In summary, noise can be associated with almost any form of human
activity and wildlife often exhibit behavioral and physiological
responses to the presence of noise. Vocalizations between individuals
of a species are important social cues that can influence habitat use,
mate selection, breeding activity, survival and ultimately population
size and persistence. In prairie chickens, the ``boom'' call transmits
information about sex, territorial status, mating condition, location,
and individual identity of the signaler and thus are important to
courtship activity and for long-range advertisement of the display
ground (Sparling 1981, p. 484). Chronic noise can interfere with these
social interactions by masking important forms of communication between
individuals. Opportunities for effective communication on the display
ground also occurs under fairly narrow conditions and disturbance
during this period may have negative consequences for reproductive
success. In lesser prairie-chickens, persistent noise likely causes lek
attendance to decline, disrupts courtship and breeding activity,
impairs habitat quality and reduces reproductive success. Noise causes
abandonment of otherwise suitable habitats and contributes to habitat
loss and degradation. Many of the development activities discussed in
the sections below, particularly energy development, emit noises that
likely cause specific behavioral responses by lesser prairie-chickens.
As these types of developments continue to increase within the
estimated occupied range, as expected, the impacts of noise from these
activities likely will be amplified and will be detrimental to the
persistence of the lesser prairie-chicken, particularly at the local
level.
Wind Power and Energy Transmission Operation and Development
Wind power is a form of renewable energy that is increasingly being
used to meet electricity demands in the United States. The U.S. Energy
Information Administration has estimated that the
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demand for electricity in the United States will grow by 39 percent
between 2005 and 2030 (U.S. Department of Energy (DOE) 2008, p. 1).
Wind energy, under one scenario, would provide 20 percent of the United
States' estimated electricity needs by 2030 and require at least 250
gigawatts of additional land-based wind power capacity to achieve
predicted levels (DOE 2008, pp. 1, 7, 10). The forecasted increase in
production would require about 125,000 turbines based on the existing
technology and equipment in use and assuming a turbine has a generating
capacity of 2 megawatts (MW). Achieving these levels also would require
expansion of the current electrical transmission system. Most of the
wind power development needed to meet these anticipated demands is
likely to come from the Great Plains States because they have high wind
resource potential, which exerts a strong, positive influence on the
amount of wind power developed within a particular State (Staid and
Guikema 2013, p. 384).
All 5 lesser prairie-chicken States are within the top 12 States
nationally for potential wind capacity, with Texas ranking second for
potential wind energy capacity and Kansas ranking third (American Wind
Energy Association 2012b, entire). The potential for wind development
within the estimated historical and occupied ranges of the lesser
prairie-chicken is apparent from the wind potential estimates developed
by the DOE's National Renewable Energy Laboratory and AWS Truewind (DOE
National Renewable Energy Laboratory 2010b, p. 1). These estimates
present the predicted mean annual wind speeds at a height of 80 m (262
ft). Areas with an average wind speed of 6.5 m/s (21.3 ft/s) and
greater at a height of 80 m (262 ft) are generally considered to have a
suitable wind resource for large scale development. All of the
estimated historical and occupied range of the lesser prairie-chicken
occurs in areas determined to have 6.5 m/s (21.3 ft/s) or higher
average windspeed (DOE National Renewable Energy Laboratory 2010b, p.
1). The vast majority of the estimated occupied range lies within areas
having wind speeds of 7.5 m/s (24.6 ft/s) or higher. These wind speeds
provide good to excellent potential for wind energy production and
represent the highest potential areas for wind energy development.
Numerous financial incentives, including grants, production
incentives and tax relief, already are available to help encourage and
promote development of renewable energy sources. Four (Colorado,
Kansas, New Mexico and Texas) of the five states that encompass the
range of the lesser prairie-chicken have renewable portfolio standards
(Hitaj 2013, pp. 408-409). Renewable portfolio standards require that
utilities obtain a certain percentage of their electricity from
renewable energy sources and there may be substantial financial
penalties for noncompliance. The percentage of renewable energy in each
portfolio varies from a low of 4.4 percent in Texas to a high of 27
percent in Colorado (Hitaj 2013, pp. 408-409). With the exception of
Texas, which was extended to 2025, all of the renewable portfolio
standards that have been established within the lesser prairie-chicken
States have an established target date of 2020. Only Oklahoma does not
have a renewable portfolio standard. Evaluation of the effects of
renewable portfolio standards have concluded that these standards have
had a significant, positive impact on the development of wind power
within those States with existing renewable portfolio standards (Yin
and Powers 2010, p. 1149). Oklahoma and New Mexico offer production
incentives, and Colorado, Kansas and Texas provide property tax
incentives. Texas also provides a corporate tax credit on equipment and
installation costs (Hitaj 2013, p. 409).
At the National level, wind power development has been incentivized
by the Federal renewable energy production tax credit, most recently
2.3 cents per kilowatt-hour. The credit typically applies to the first
10 years of operation but unused credits may be carried forward for up
to 20 years. This credit first became available in 1992 and has had an
important effect on investment and development by the wind power
industry (Hitaj 2013, p. 404; Staid and Guikema 2013, p. 378).
Development has slowed during periods when the availability of the
Federal production tax credit was uncertain (Bird et al. 2005, p. 1398;
Staid and Guikema 2013, p. 378). The production tax credit expired in
2012 but was extended in January of 2013 through the end of the
calendar year. The Federal production tax credit has since expired and
its future is currently unknown. Typically, for years in which the
production tax credit has not been in place development has slowed and
the years prior to expiration have shown a boom in wind power
development (Blair 2012, p. 10).
Wind farm development begins with site monitoring and collection of
meteorological data to characterize the available wind regime. Turbines
are installed after the meteorological data indicate appropriate siting
and spacing. The tubular towers of most commercial, utility-scale
onshore wind turbines are between 65 m (213 ft) and 100 m (328 ft)
tall. The most common system uses three rotor blades and can have a
diameter of as much as 100 m (328 ft). The total height of the system
is measured when a turbine blade is in the 12 o'clock position and will
vary depending on the length of the blade. With blades in place, a
typical system will exceed 100 m (328 ft) in height. A wind farm will
vary in size depending on the size of the turbines and amount of land
available. Typical wind farm arrays consist of 30 to 150 towers each
supporting a single turbine. The individual permanent footprint of a
single turbine unit, about 0.3 to 0.4 ha (0.75 to 1 ac), is relatively
small in comparison with the overall footprint of the entire array (DOE
2008, pp. 110-111). Spacing between each turbine is usually 5 to 10
rotor diameters to avoid interference between turbines. Roads are
necessary to access the turbine sites for installation and maintenance.
One or more substations, where the generated electricity is collected
and transmitted, also may be built depending on the size of the wind
farm. Considering the initial capital investment, and that the service
life of a single turbine is at least 20 years (DOE 2008, p. 16), we
expect most wind power developments to be in place for at least 20
years.
Siting of commercially viable wind energy developments is largely
based on wind intensity (speed) and consistency, and requires the
ability to transmit generated power to the users. Any discussion of the
effects of wind energy development on the lesser prairie-chicken also
must take into consideration the influence of the transmission lines
critical to distribution of the energy generated by wind turbines.
Transmission lines can traverse long distances across the landscape and
can be both above ground and underground, although the vast majority of
transmission lines are erected above ground. Most of the impacts to
lesser prairie-chicken associated with transmission lines are with the
aboveground systems. Support structures vary in height depending on the
size of the line. Most high-voltage powerline towers are 30 to 38 m (98
to 125 ft) high but can be higher if the need arises. Local
distribution lines are usually much shorter in height but can still
contribute to fragmentation of the landscape. Local distribution lines,
while more often are erected above ground, can be placed below ground.
Financial investment in the
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transmission of electrical power has been steadily climbing since the
late 1990s and includes not only the cost of maintaining the existing
system but also includes costs associated with increasing reliability
and development of new transmission lines (DOE 2008, p. 94). Manville
(2005, p. 1052) reported that there are at least 804,500 km (500,000
mi) of transmission lines (lines carrying greater than 115 kilovolts
(kV)) within the United States. Recent transmission-related activities
within the estimated historical and occupied ranges include the
creation of Competitive Renewable Energy Zones in Texas and the ``X
plan'' under consideration by the Southwest Power Pool, which are
discussed in more detail below.
Wind energy developments already exist within the estimated
historical range of the lesser prairie-chicken, some of which have
impacted occupied habitat. The 5 lesser prairie-chicken States are all
within the top 20 States nationally for installed wind capacity
(American Wind Energy Association 2012a, p. 6). By the close of 1999,
the installed capacity, in MW, of wind power facilities within the five
lesser prairie-chicken States was 209 MW; the majority, 184 MW, was
provided by the State of Texas (DOE National Renewable Energy
Laboratory 2010a, p. 1). At the close of 2012, the installed capacity
within the five lesser prairie-chicken States had grown to 21,140 MW
(Wiser and Bollinger 2013, p. 9). Although not all of this installed
capacity is located within the estimated historical or occupied ranges
of the lesser prairie-chicken, and includes any offshore wind projects
in Texas (one non-commercial tower at close of 2013), there is
considerable overlap between the estimated historical and occupied
ranges and those areas having good to excellent wind potential, as
determined by the DOE's National Renewable Energy Laboratory (DOE
National Renewable Energy Laboratory 2010b, p. 1). Areas having good to
excellent wind potential represent the highest priority sites for wind
power development, particularly where projects have access to
transmission systems with available capability.
Within the estimated occupied range in Colorado, existing wind
projects are located in Baca, Bent, and Prowers Counties. Colorado's
installed wind capacity grew by 39 percent in 2011 (American Wind
Energy Association 2012b, entire). In Kansas, Barber, Ford, Gray,
Kiowa, and Wichita Counties have existing wind projects. Kansas is
expected to double their existing capacity in 2012 and leads the United
States with the most wind power under construction (American Wind
Energy Association 2012b, entire). By the close of 2012, Kansas had
installed the most capacity (1,441 MW) of any State (Wiser and
Bollinger 2013, p. 9). Curry, Roosevelt, and Quay Counties in the New
Mexico portion of the estimated occupied range currently have operating
wind projects. There are 14,136 MW (roughly 5,654 2.5 MW turbines) in
the queue awaiting construction (American Wind Energy Association
2012b, entire). In Oklahoma, Custer, Dewey, Harper, Roger Mills, and
Woodward Counties have existing wind farms. Approximately 393 MW are
under construction and there is another 14,667 MW in the queue awaiting
construction. In Texas, Carson, Moore, Oldham and Randall counties have
existing wind farms. Wiser and Bollinger (2013, p. 12) reported that
nationwide, by the end of 2012, there were about 125 GW of wind power
projects within the interconnection queues awaiting development. This
figure represents more than double the existing developed wind capacity
in the United States with Texas (Electric Reliability Council of Texas)
and the Southwest Power Pool having almost 32 percent of the total
capacity in the interconnection queues (Wiser and Bollinger 2013, pp.
12-13). These two transmission system operators encompass almost all of
the estimated occupied range of the lesser prairie-chicken in Kansas,
New Mexico, Oklahoma and Texas.
Most published literature on the effects of wind development on
birds focuses on the risks of collision with towers or turbine blades.
Until recently, there was very little published research specific to
the effects of wind turbines and transmission lines on prairie grouse
and much of that focuses on avoidance of the infrastructure associated
with renewable energy development (see previous discussion on vertical
structures in the ``Causes of Habitat Fragmentation within Lesser
Prairie-Chicken Range'' section above and discussion that follows). We
find that many wind power facilities are not monitored consistently
enough to detect collision mortalities and the observed avoidance of
and displacement influenced by the vertical infrastructure observed in
prairie grouse likely minimizes the opportunity for such collisions to
occur. However, Vodenhal et al. (2011, unpaginated) has observed both
greater prairie-chickens and plains sharp-tailed grouse (Tympanuchus
phasianellus jamesi) lekking near the Ainsworth Wind Energy Facility in
Nebraska since 2006. The average distance of the observed display
grounds to the nearest wind turbine tower was 1,430 m (4,689 ft) for
greater prairie-chickens and 1,178 m (3,864 ft) for sharp-tailed
grouse.
Greater prairie-chickens also were observed within a wind power
development in Kansas, indicating that strong avoidance of such
developments by prairie grouse is not always evident and, under some
conditions, the impacts may occasionally be beneficial. Winder et al.
(2013, entire), as part of a larger study that examined the
environmental impacts of the Meridian Way wind power project in
northcentral Kansas, examined the effects of wind energy development on
survival of female greater prairie-chickens. The study site was located
in an area that was considerably fragmented, having a relatively high
density of roads and moderately high incidence of row crop agriculture
(35 percent) for a primarily grassland landscape (Winder et al. 2013,
p. 3). They concluded that development of this wind power facility did
not negatively impact survival of female greater prairie-chickens. In
fact, survival increased significantly post construction (Winder et al.
2013, p. 5), perhaps in response to changes in predator behavior
following completion of construction in 2008. Prior to construction,
they observed that the majority of greater prairie-chicken mortality
was due to predation, principally during the lekking season (Winder et
al. 2013, p. 6). Post construction, they speculated that the presence
of the wind farm altered predator activity on the study area although
they did not specifically record information on numbers of predators
before and after construction (Winder et al. 2013, p. 7).
Because Winder et al. (2013, entire) only provided information on
adult survival associated with wind farm development; we lack
information on recruitment and the long-term persistence of greater
prairie-chickens at this site. While adult survival is one of several
demographic factors that influence population growth, it is rarely as
important as nest and brood survival in prairie grouse, particularly
lesser prairie-chickens (Pitman et al. 2006b, p. 679; Hagen et al.
2009, pp. 1329-1330; Grisham 2012, p. 153; Hagen et al. 2013, p. 750).
The lack of information on nest and brood survival, thus recruitment,
could result in misrepresentation of the impacts of the wind farm. For
example, female survival may have been demonstrated to increase post
construction, but we do not know from this study if the females nested
or the fate of those nests and of any broods
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that might have been produced. Previous studies on lesser prairie-
chickens demonstrated that females would not nest within specific
distances of certain vertical structures (Pitman et al. 2005, pp. 1267-
1268). Additionally, Winder et al. (2013, entire) did not provide any
information on habitat selectivity by the adults or persistence of leks
at the study site. Consequently, we do not know whether the birds
actively chose to remain at that location, or simply continued to use
the only remaining usable habitat and are unable to persist long term.
While they did report that over 75 percent of the leks were located
within 8 km (5 mi) of a turbine, the fate of those leks post
construction were not reported (Winder et al. 2013, p. 3).
However, additional information regarding this study is available
that provides more insight into some aspects of the effects of wind
power development on greater prairie-chickens and helps address some of
the concerns presented above (Sandercock et al. 2012, entire). With
respect to lek persistence, the distance from a wind turbine was not
shown to have a statistically significant effect on the probability of
lek persistence (Sandercock et al. 2012, p. 11). However, lek sites
located less than 5 km (3.1 mi) from a turbine had a lower probability
of persistence than leks that were located larger distances from a
turbine, leading the authors to conclude that wind energy development
negatively impacted lek persistence (Sandercock et al. 2012, p. 11).
Females were not observed to select nest sites at random; instead they
preferred to nest in native grasslands (Sandercock et al. 2012, p. 25).
Although females may have remained at the site post construction due to
the continued presence of suitable grassland habitat, Sandercock et al.
(2012, p. 3) did not observe any impacts of wind power development on
nest site selection, nesting success, or female reproductive effort.
However, they did report weak evidence for avoidance of wind turbines
by female greater prairie-chickens that were not attending nests or
broods during the breeding season (Sandercock et al. 2012, p. 25).
Prior to construction, some 20 percent of the observed movements would
have crossed the location of the proposed wind farm but post
construction only 11 percent of the observed movements crossed the area
where actual wind energy infrastructure existed. They concluded that
females were more likely to move away from wind power infrastructure
and may lead to fragmentation of existing populations post construction
(Sandercock et al. 2012, p. 25).
When male fitness was examined, they observed that the residual
body mass of male greater prairie-chickens at lek sites near turbines
declined post construction and may have negatively impacted individual
survival or reproductive performance (Sandercock et al. 2012, p. 53).
Reduced body condition also may impact flight performance and increase
predation risk in males displaying on leks. Based on counts of males at
leks, Sandercock et al. (2012, p. 61), did not find that greater
prairie-chicken population size was negatively impacted by wind power
development. However, following construction, they observed that the
number of males declined over the next 3 years of the study and
resulted in finite rates of population change indicative of a declining
population (Sandercock et al. (2012, p. 61). They also observed that
wind power development did appear to reduce dispersal rates or change
settlement patterns in greater prairie-chickens, leading to higher
rates of relatedness among males.
As evident from the study of the Meridian Way Wind Power
Development, under some conditions, and with some species of grouse,
the displacement effects of wind power projects may not be as strong as
observed with other types of developments. In the instance of female
survival, the presence of wind turbines may enhance survival,
particularly if the presence of the turbines leads to reduced rates of
predation. However, at least in this study, the presence of the wind
power development was not entirely benign and the fragmented nature of
the landscape surrounding the study site may have exerted a stronger
influence on the observed behavior of greater prairie-chickens than did
the presence of the wind turbines over the three year period examined
in this study. Under these conditions, the birds may have perceived the
wind project site as more suitable than the surrounding landscape.
These studies also appear to indicate that greater prairie-chickens
may be more tolerant of wind turbine towers than other species of
prairie grouse (Winder et al. (2013, p. 9). Hagen (2004, p. 101)
cautions that occurrence near such structures may be due to strong site
fidelity or continued use of suitable habitat remnants and that these
populations actually may not be able to sustain themselves without
immigration from surrounding populations (i.e., population sink). If
greater prairie-chickens are less sensitive to wind energy development,
this may, at least partially explain why greater prairie-chickens also
continue to utilize grassland habitats at the Ainsworth Wind Energy
Facility in Nebraska.
Currently, we have no documentation of any collision-related
mortality in wind farms for lesser prairie-chickens. In Kansas, Winder
et al. (2013, p. 8) did observe collision mortality before and after
construction of a wind farm but those mortalities were due to fences or
power lines and not the turbines themselves. Similarly, no deaths of
gallinaceous birds (upland game birds) were reported in a comprehensive
review of avian collisions and wind farms in the United States; the
authors hypothesized that the average tower height and flight height of
grouse minimized the risk of collision (Erickson et al. 2001, pp. 8,
11, 14, 15). However, Johnson and Erickson (2011, p. 17) monitored
commercial scale wind farms in the Columbia Plateau of Washington and
Oregon and observed that about 13 percent of the observed collision
mortalities were nonnative upland game birds: Ring-necked pheasant,
gray partridge (Perdix perdix), and chukar (Alectoris chukar). Although
the risk of collision with individual wind turbines appears low,
commercial wind energy developments can directly alter existing
habitat, contribute to habitat and population fragmentation, and cause
more subtle alterations that influence how species use habitats in
proximity to these developments (National Research Council 2007, pp.
72-84).
Wind turbines can generate significant levels of noise. Estimates
of the noise created by wind turbines vary depending on a variety of
factors. Cummins (2012, p. 12-15) summarizes information on wind
turbine noise, including use of sound contour maps to explain how
turbine noise changes with distance, topography, and turbine layout.
Generally, the wind energy industry expects that turbine noise will
average 35 to 45 dB at 350 m (1,150 ft) from an operating turbine but
in some instances the sound may continue to exceed 45 dB as far as 0.8
km (0.5 mi) from the sound source (Cummings 2012, p. 13). Noise levels
obviously could peak at levels higher than the average. Most noise
produced by wind turbines also is low frequency, typically 0.25 kHz or
less (Cummings 2012, p. 40). Noise levels of this magnitude and
frequency may generate a behavioral response in lesser prairie-chickens
and may result in avoidance of areas of otherwise suitable habitat.
Electrical transmission lines can directly affect prairie grouse by
posing
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a collision hazard (Leopold 1933, p. 353; Connelly et al. 2000, p. 974;
Patten et al. 2005b, pp. 240, 242) and can indirectly lead to decreased
lek recruitment, increased predation, and facilitate invasion by
nonnative plants. The physical footprint of the actual project is
typically much smaller than the actual impact of the transmission line
itself. Lesser prairie-chickens exhibit strong avoidance of tall
vertical features such as utility transmission lines (Pitman et al.
2005, pp. 1267-1268). In typical lesser prairie-chicken habitat where
vegetation is low and the terrain is relatively flat, power lines and
power poles provide attractive hunting, loafing, and roosting perches
for many species of raptors (Steenhof et al. 1993, p. 27). The elevated
advantage of transmission lines and power poles serve to increase a
raptor's range of vision, allow for greater speed during attacks on
prey, and serve as territorial markers. Raptors actively seek out power
lines and poles in extensive grassland areas where natural perches are
limited. While the effect of this predation on lesser prairie-chickens
undoubtedly depends on raptor densities, as the number of perches or
nesting features increase, the impact of avian predation will increase.
Additional discussion concerning the influence of vertical structures
on predation of lesser prairie-chickens can be found in the ``Causes of
Habitat Fragmentation Within Lesser Prairie-Chicken Range'' section
above, and additional information on predation is provided in a
separate discussion under ``Predation'' below.
Transmission lines, particularly due to their length, can be a
significant barrier to dispersal of prairie grouse, disrupting
movements to feeding, breeding, and roosting areas. Both lesser and
greater prairie-chickens avoided otherwise suitable habitat near
transmission lines and crossed these power lines much less often than
nearby roads, suggesting that power lines are a particularly strong
barrier to movement (Pruett et al. 2009a, pp. 1255-1257). Because
lesser prairie-chickens avoid tall vertical structures like
transmission lines and because transmission lines can increase
predation rates, leks located in the vicinity of these structures may
see reduced recruitment of new males to the lek (Braun et al. 2002, pp.
339-340, 343-344). Lacking recruitment, leks may disappear as the
number of older males decline due to death or emigration. Linear
corridors such as road networks, pipelines, and transmission line
rights-of-way can create soil conditions conducive to the spread of
invasive plant species, at least in semiarid sagebrush habitats (Knick
et al. 2003, p. 619; Gelbard and Belnap 2003, pp. 424-425), but the
scope of this impact within the range of the lesser prairie-chicken is
unknown. Spread of invasive plants is most critical where established
populations of invasive plants begin invading areas of native grassland
vegetation.
Electromagnetic fields associated with transmission lines alter the
behavior, physiology, endocrine systems, and immune function in birds,
with negative consequences on reproduction and development (Fernie and
Reynolds 2005, p. 135). Birds are diverse in their sensitivities to
electromagnetic field exposure with domestic chickens known to be very
sensitive. Although many raptor species are less affected by these
fields (Fernie and Reynolds 2005, p. 135), no specific studies have
been conducted on lesser prairie-chickens. However electromagnetic
fields associated with powerlines and telecommunication towers may
explain, at least in part, avoidance of such structures by sage grouse
(Wisdom et al. 2011, pp. 467-468).
Identification of the actual number of proposed wind energy
projects that will be built within the range of the lesser prairie-
chicken in any future timeframe is difficult to accurately discern,
particularly at smaller scales. Nationally, during the period from 1997
to 2002, the average annual growth rate in wind power was 24 percent
(Bird et al. 2005, p. 1397). An analysis of the Federal Aviation
Administration's Daily Digital Obstruction File (obstacle database) can
provide some insight into the number of existing and proposed wind
generation towers. The Federal Aviation Administration is responsible
for ensuring wind towers and other vertical structures are constructed
in a manner that ensures the safety and efficient use of the navigable
airspace. In accomplishing this mission, they evaluate applications
submitted by the party responsible for the proposed construction and
alteration of these structures. Included in the application is
information on the precise location of the proposed structure. This
information can be used, in conjunction with other databases, to
determine the number of existing and proposed wind generation towers
within the estimated historical and occupied ranges of the lesser
prairie-chicken.
Analysis of the information contained in the obstacle database, as
available in April 2010, revealed that 6,279 vertical structures, such
as wind turbines, telecommunication towers, radio towers,
meteorological towers and similar vertical structures, were located
within the estimated historical range of the lesser prairie-chicken at
that time. An additional estimated 8,501 vertical structures had been
cleared for construction, and another 1,693 vertical structures were
pending approval within the estimated historical range of the lesser
prairie-chicken. While not all of these structures are wind generation
towers, the vast majority are. A similar analysis was conducted on
lesser prairie-chicken estimated occupied range. As of April 2010, the
estimated occupied range included 173 vertical structures.
Approximately 1,950 vertical structures had been cleared for
construction, and another 250 vertical structures were awaiting
approval. In January of 2012, an analysis of the Federal Aviation
Administration's obstacle database showed that there were 405 existing
wind turbines in or within 1.6 km (1 mi) of the estimated occupied
range. In March of 2012, there were 4,887 wind turbines awaiting
construction, based on the Federal Aviation Administration's
obstruction evaluation database.
For this final rule, we conducted a more complete analysis of
vertical structures in an effort to update the analysis we conducted in
2010, as explained above. As before, we used the Federal Aviation
Administration's Daily Digital Obstruction File, current as of November
2013 to identify the vertical structures that were built and remain
operational between 1974 and 2013. Generally these are vertical
structures, such as wind towers and communication towers, that are at
least 60.6 m (199 ft) above ground level or otherwise have been deemed
a hazard to aviation. Within the historical range of the lesser
prairie-chicken, there were a total of 17,800 vertical structures
identified, of which 9,109 were classified as windmill type (wind
turbine) structures. Of those windmill structures 1,074 had been
approved after December 12, 2012, the date of our proposed rule. Within
the EOR +10, as previously described, there were 3,714 vertical
structures identified in the database of which about 1,398 vertical
structures were classified by the Federal Aviation Administration (FAA)
as windmill type structures. Of those structures, 405 were approved
after December 12, 2012, the date of our proposed rule.
Similarly, we used a portion of the FAA's Obstruction Evaluation/
Airport Airspace Analysis database, current as of December 2013, to
estimate the number of wind turbines and meteorological towers that are
awaiting construction or alteration, pending
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approval from the FAA. We included meteorological towers because their
presence is often a good first indication that an area is being studied
for wind development or as a means of monitoring wind and related data
within an existing wind farm. These structures/features are grouped
into four classes: Determined hazard--structure has been given a hazard
determination by FAA; determined with no build date--evaluation by FAA
is complete, structure is not a hazard but no completion date has been
provided; determined with build date--evaluation by FAA is complete,
structure is not a hazard and a completion date has been provided; not
yet determined--all structures proposed to be built and have submitted
the Form 7460-1 but for which FAA has not yet made a determination as
to whether the structure poses a hazard to air navigation. Our analysis
of the historical range revealed that 36,197 wind and meteorological
tower features have been proposed for development. Of that total number
of features, 12,020 windmill features and 169 meteorological towers
have been proposed for development within the EOR +10. Within the EOR
+10, 1,513 windmill features and 37 meteorological towers were
submitted for approval by FAA after the date of publication of our
proposed listing rule on December 12, 2012.
Additionally, the Southwest Power Pool provides public access to
its Generation Interconnection Queue (https://studies.spp.org/GenInterHomePage.cfm), which provides all of the active requests for
connection from new energy generation sources requiring Southwest Power
Pool approval prior to connecting with the transmission grid. The
Southwest Power Pool is a regional transmission organization which
overlaps all or portions of nine States, including Kansas, New Mexico,
Oklahoma, and Texas, and functions to ensure reliable supplies of
power, adequate transmission infrastructure, and competitive wholesale
prices of electricity exist. The Southwest Power Pool's jurisdiction in
Kansas, New Mexico, Oklahoma, and Texas does not include all of the
historical or estimated occupied range of the lesser prairie-chicken
but serves as a very conservative indicator of the amount of interest
in wind power development in these four States. In 2010, within the
Southwest Power Pool portion of Kansas, New Mexico, Oklahoma, and
Texas, there were 177 wind generation interconnection study requests
totaling 31,883 MW awaiting approval. A maximum development scenario,
assuming all of these projects are built and they install all 2.0 MW
wind turbines, would result in approximately 15,941 wind turbines being
erected in these four States. Recently we conducted an additional
analysis of the current information, as of January 28, 2014, within the
Southwest Power Pool's Generation Interconnection Queue. We conducted
this analysis to obtain a more recent evaluation of existing and
proposed wind power development within the Southwest Power Pool's
jurisdiction in portions of Kansas, New Mexico, Oklahoma, and Texas.
There were a total of 74 projects in the queue within the counties
encompassed by the EOR +10. Thirty-one of those projects were in
commercial operation, thirty-eight were identified as being in planning
or development and five projects were suspended and not currently
moving forward. Fifteen of those thirty-eight projects, totaling
3,208.3 MW of power, that were identified as being in active planning
or development were submitted for consideration after publication of
our proposed rule on December 12, 2012. The total planned power
production, in MW, for the projects in operation and in planning or
development were 4,706.5 and 9,324.3, respectively. If we assume a
typical turbine size of 2.0 MW, an estimated 7,015 turbines have been
built or are in planning and development at this time within the
counties encompassed by the EOR +10 within the Southwest Power Pool
jurisdiction. These estimated values do not include development and
planning within the Electric Reliability Council of Texas whose
jurisdiction extends over most of the Texas Panhandle.
The possible scope of this anticipated wind energy development on
the status of the lesser prairie-chicken can readily be seen in
Oklahoma where the locations of many of the current and historically
occupied leks are known. Most remaining large tracts of untilled native
rangeland, and hence lesser prairie-chicken habitat, occur on
topographic ridges. Leks, the traditional mating grounds of prairie
grouse, are consistently located on elevated grassland sites with few
vertical obstructions (Flock 2002, p. 35). Because of the increased
elevation, these ridges also are prime sites for wind turbine
development. In cooperation with ODWC, Service personnel in 2005
quantified the potential degree of wind energy development in relation
to existing populations of lesser prairie-chicken in Oklahoma. All
active and historically occupied lesser prairie-chicken lek locations
in Oklahoma, as of the mid 1990s (n = 96), and the estimated occupied
range, were compared with the Oklahoma Neural Net Wind Power
Development Potential Model map created by the Oklahoma Wind Power
Assessment project. The mapping analysis revealed that 35 percent of
the estimated occupied range in Oklahoma is within areas designated by
the Oklahoma Wind Power Assessment as ``excellent'' for wind energy
development. When both the ``excellent'' and ``good'' wind energy
development classes are combined, about 55 percent of the lesser
prairie-chicken's occupied range in Oklahoma lies within those two
classes.
When leks were examined, the analysis revealed a nearly complete
overlap on all known active and historically occupied lek locations,
based on the known active leks during the mid 1990s. Roughly 91 percent
of the known lesser prairie-chicken lek sites in Oklahoma are within 8
km (5 mi) of land classified as ``excellent'' for wind development
(O'Meilia 2005). Over half (53 percent) of all known lek sites in
Oklahoma occur within 1.6 km (1 mi) of lands classified as
``excellent'' for commercial wind energy development. This second
metric is particularly relevant considering a majority of lesser
prairie-chicken nesting generally occurs, on average, within 3.4 km
(2.1 mi) of active leks (Hagen and Giesen 2005, p. 2). Robel (2002, p.
23) estimated that habitat within 1.6 km (1.0 mi) or more of a single
commercial-scale wind turbine is rendered unsuitable for greater
prairie chickens due to their tendency to avoid tall structures. Using
Robel's (2002, p. 23) estimate of this zone of avoidance (1.6 km or 1.0
mi) for a single commercial-scale wind turbine, development of
commercial wind farms, which would consist of multiple turbines spaced
over a large area (typical wind farm arrays consist of 30 to 150 towers
each supporting a single turbine), likely will have a significant
adverse influence on reproduction of the lesser prairie-chicken,
provided lesser prairie-chickens consistently avoid nesting within 1.6
km (1 mi) of each turbine.
Unfortunately, a similar analysis of active and historically
occupied leks is not available for the other States due to a lack of
comparable information on the location of lek sites. Considering
western Kansas currently supports the largest number and distribution
of lesser prairie-chickens of all five States, the influence of wind
energy development
[[Page 20050]]
on the lesser prairie-chicken in Kansas would likely be equally, if not
more, significant. As previously discussed in this section, wind power
development in Kansas is expanding (Wiser and Bollinger 2013, p. 9) and
the industry is seeking to continue development of additional wind
farms. In 2006, the Governor of Kansas initiated the Governor's 2015
Renewable Energy Challenge, an objective of which is to have 1,000 MW
of renewable energy capacity in Kansas by 2015 (Cita et al. 2008, p.
1). A cost-benefit study (Cita et al. 2008, Appendix B) found that wind
power was the most likely and most cost effective form of renewable
energy resource for Kansas. Modestly assuming an average of 2 MW per
turbine--most commercial scale turbines are between 1.5 and 2.5 MW--an
estimated 500 turbines would have to be erected in Kansas if this goal
is to be met.
While not all of those turbines would be placed in occupied
habitat, and some overlap in avoidance would occur if turbines were
oriented in a typical wind farm array, the potential impact could be
significant. First, the best wind potential in Kansas occurs in the
western two-thirds of the State and largely overlaps the estimated
occupied lesser prairie-chicken range (DOE, National Renewable energy
Laboratory 2010b, p. 1). Additionally, Kansas has a voluntary
moratorium on the development of wind power in the Flint Hills of
eastern Kansas, which likely will shift the focus of development into
the central and western portions of the State. Taking these two factors
into consideration, construction of much of the new wind power
anticipated in the Governor's 2015 Renewable Energy Challenge likely
would occur in the western two-thirds of Kansas. If we assume that even
one-half of the estimated 500 turbines are placed in lesser prairie-
chicken range, 250 turbines would individually impact over 101,000 ha
(250,000 ac), based on an avoidance distance of 1.6 km (1 mi). The
habitat loss resulting from the above scenario would further reduce the
extent of large, unfragmented parcels and influence connectivity
between remaining occupied blocks of habitat, reducing the amount of
suitable habitat available to the lesser prairie-chicken. Consequently,
siting of wind energy arrays and associated facilities, including
electrical transmission lines, appears to be a serious threat to lesser
prairie-chickens in western Kansas within the near future (Rodgers
2007a).
In Colorado, the DOE, National Renewable Energy Laboratory (2010b,
p. 1) rated the southeastern corner of Colorado as having good wind
resources, the largest area of Colorado with that ranking. The area
almost completely overlaps the estimated occupied range of the lesser
prairie-chicken in Colorado. Colorado currently ranks 10th in both
total installed capacity and number of commercial scale wind turbines
in operation (AWEA 2014). The 162 MW Green Wind Power Project and 75 MW
Twin Buttes Wind Project are located with Prowers County which includes
portions of the estimated occupied range. The CPW reported that
commercial wind development is occurring in Colorado, but that most of
the effort is currently centered north of the estimated occupied range
of lesser prairie-chicken in southeastern Colorado.
Wind energy development in New Mexico is less likely than in other
States within the range of the lesser prairie-chicken because the
suitability for wind energy development in the estimated occupied range
of the lesser prairie-chicken in New Mexico is only rated as fair (DOE,
National Renewable Energy Laboratory 2010b, p. 1). However, some parts
of northeastern New Mexico within lesser prairie-chicken historical
range have been rated as excellent. Northeastern New Mexico is
important to lesser prairie-chicken conservation because this area is
vital to efforts to reestablish or reconnect the New Mexico lesser
prairie-chicken population to those in Colorado and the Texas
panhandle.
In Texas, the Public Utility Commission recently directed the
Electric Reliability Council of Texas (ERCOT) to develop transmission
plans for wind capacity to accommodate between 10,000 and 25,000 MW of
power (American Wind Energy Association 2007b, pp. 2-3). ERCOT is a
regional transmission organization with jurisdiction over most of
Texas. The remainder of Texas, largely the Texas panhandle, lies within
the jurisdiction of the Southwest Power Pool. A recent assessment from
ERCOT identified more than 130,000 MW of high-quality wind sites in
Texas, more electricity than the entire State currently uses. The
establishment of Competitive Renewable Energy Zones by ERCOT within the
State of Texas will facilitate wind energy development throughout
western Texas. Based on the development priority of each zone, the top
four Competitive Renewable Energy Zones, which are designated for
future wind energy development in the Texas panhandle, are located
within occupied and historical lesser prairie-chicken habitat in the
Texas panhandle.
Wind energy and associated transmission line development in the
Texas panhandle and portions of west Texas represent a threat to extant
lesser prairie-chicken populations in the State. Once established, wind
farms and associated transmission features would severely hamper future
efforts to restore population connectivity and gene flow (transfer of
genetic information from one population to another) between existing
populations that are currently separated by incompatible land uses in
the Texas panhandle.
Development of high-capacity transmission lines is critical to the
development of the anticipated wind energy resources in ensuring that
the generated power can be delivered to the consumer. According to
ERCOT (American Wind Energy Association 2007a, p. 9), every $1 billion
invested in new transmission capacity enables the construction of $6
billion of new wind farms. We estimate, based on a spatial analysis
prepared by The Nature Conservancy in 2011 under their license
agreement with Ventyx Energy Corporation, that there are 35,220 km
(21,885 mi) of transmission lines, having a capacity of 69 kilovolts
(kV) or larger, in service within the historical range of the lesser
prairie-chicken. Within the estimated currently occupied range, this
analysis estimated that about 3,610 km (2,243 mi) of transmission lines
with a capacity of 69kV and larger are currently in service. Within the
estimated occupied range, this same analysis revealed that an
additional 856 km (532 mi) of 69kV or higher transmission line is
anticipated to be in service within the near future.
Because we did not have access to the same commercially available
dataset used by The Nature Conservancy, but we wanted to provide an
updated analysis of the scope of transmission line development within
the range of the lesser prairie-chicken, we used transmission line data
maintained by the Southwest Power Pool. This dataset has some
limitations, particularly for Texas and New Mexico which are largely
outside of the jurisdiction of the Southwest Power Pool. However the
data can be used to get a sense of the scope of existing development
within portions of the range. Our analysis revealed that 9,153 km
(5,687.4 mi) of transmission lines having a capacity of 69kV or higher
exist within those portions of the estimated occupied range that lie
within the jurisdiction of the Southwest Power Pool. Although the
analysis performed by The Nature Conservancy using the Ventyx Energy
Corporation dataset has not been updated since 2011, we can use that
analysis to derive the density of transmission lines in existence at
that
[[Page 20051]]
time within the estimated occupied range. Assuming all of the 69 kV or
larger transmission lines in service at the time of that analysis
(about 3,610 km (2,243 mi) of transmission lines) are still in service,
the density of these transmission lines would be 0.04 km/sq km (0.07
mi/sq mi). Although similar information for lesser prairie-chickens is
not available, transmission line densities were particularly important
in assessing the value of habitat for greater sage grouse. Habitat
suitability for sage grouse was the highest when densities of
transmission lines were below 0.06 km/sq km (Knick 2013 et al., p. 6).
Leks were absent from areas where transmission line densities exceeded
0.20 km/sq km (Knick 2013 et al., p. 6).
The Southwest Power Pool also has information about several
proposed electric transmission line upgrades. This organization
identified approximately 423 km (263 mi) of proposed new transmission
lines, commonly referred to as the ``X Plan'', that were being
evaluated during the transmission planning process. Transmission
planning continues to move forward, and numerous alternatives are being
evaluated, many of which will increase transmission capacity throughout
all or portions of the estimated occupied lesser prairie-chicken range
and serve to catalyze extensive wind energy development throughout much
of the remaining estimated occupied lesser prairie-chicken range in
Kansas, Oklahoma, and Texas. Additionally, Clean Line Energy is
planning to build a high voltage direct current transmission line
(Plains and Eastern Clean Line) that would originate within Texas
County of the Oklahoma panhandle, travel the length of the panhandle
region, and then drop south to near Woodward, Oklahoma, before
continuing eastward across Oklahoma, Arkansas and western Tennessee.
The Plains and Eastern Clean Line project would deliver a maximum of
3,500 MW of electric power. Increased transmission capacity provided by
the Clean Line project will facilitate development of additional wind
power. Additionally, the fragmenting effect of this transmission line
is a significant concern. Corman (2011, pp. 151-152) concluded that the
northeast Texas population of lesser prairie-chickens was too small to
retain high amounts of genetic diversity over the long term. He thought
connectivity between the Oklahoma and Kansas lesser prairie-chicken
populations was crucial to maintaining persistence in the northeast
Texas population. Should lesser prairie-chickens avoid areas adjacent
to this high voltage transmission line, as demonstrated with a
comparable high voltage transmission line (Pruett 2009a, pp. 1255-
1257), movement between populations across the line will diminish
significantly. A draft Environmental Impact Statement on this project
is anticipated in the fall of 2014; the project cannot proceed until
that analysis is complete and the potential route approved. The project
is expected to commence commercial operation now earlier than 2018.
Another similar high voltage direct current transmission line
proposed by Clean Line Energy Partners, known as the Grain Belt
Express, is planned for Kansas. The line would originate in west-
central Kansas and continue to its endpoint in the upper Midwestern
United States. Very little opportunity to interconnect with these
direct current lines exists due to the anticipated high cost associated
with development of an appropriate interconnecting substation.
Consequently, most of the anticipated wind power that will be
transmitted across the Oklahoma and Kansas projects likely will occur
near the western terminals associated with these two Clean Line
projects. Assuming a fairly realistic build-out scenario for these
transmission lines, in which wind power projects would most likely be
constructed within 64 km (40 mi) of the western end points of each line
(77 FR 75624), much of the estimated occupied range in Colorado,
Kansas, Oklahoma, and northeast Texas falls within the anticipated
development zone. Although both of these projects are still relatively
early in the planning process, and the specific environmental impacts
have yet to be determined, a reasonably likely wind power development
scenario would place much of the estimated occupied range at risk of
wind power development.
In summary, wind energy and associated infrastructure development
is occurring now and is expected to continue into the future within
occupied portions of lesser prairie-chicken habitat. Proposed
transmission line improvements, such as the proposed Plains and Eastern
Clean Line project, will serve to facilitate further development of
additional wind energy resources but will take several years to
commence operations. Future wind energy developments, based on the
known locations of areas with excellent to good wind energy development
potential, likely will have substantial overlap with known lesser
prairie-chicken populations. There is little published information on
the specific effects of wind power development on lesser prairie-
chickens. Most published reports on the effects of wind power
development on birds focus on the risks of collision with towers or
turbine blades. However, we do not expect that significant numbers of
collisions with spinning blades would be likely to occur due to
avoidance of the wind towers and associated transmission lines by
lesser prairie-chickens. The most significant impact of wind energy
development on lesser prairie-chickens is caused by the avoidance of
useable space due the presence of vertical structures (turbine towers
and transmission lines) within suitable habitat. The noise produced by
wind turbines also is anticipated to contribute to behavioral avoidance
of these structures. Avoidance of these vertical structures by lesser
prairie-chickens can be as much as 1.6 km (1 mi), resulting in large
areas (814 ha (2,011 ac) for a single turbine) of unsuitable habitat
relative to the overall footprint of a single turbine. Where such
development has occurred or is likely to occur, these areas are no
longer suitable for lesser prairie-chicken even though many of the
typical habitat components used by lesser prairie-chicken remain.
Therefore, considering the scale of current and future wind development
that is likely within the range of the lesser prairie-chicken and the
significant avoidance response of the species to these developments, we
conclude that wind energy development is a threat to the species,
especially when considered in combination with other habitat
fragmenting activities.
Roads and Other Similar Linear Features
Similar to transmission lines, roads are a linear feature on the
landscape that can contribute to loss and fragmentation of habitat
suitable for the species and can fragment populations as a result of
behavioral avoidance. The observed behavioral avoidance associated with
roads is likely due to noise, visual disturbance, and increased
predator movements paralleling roads. For example, roads are known to
contribute to lek abandonment when they disrupt the important habitat
features associated with lek sites (Crawford and Bolen 1976b, p. 239).
The presence of roads allows human encroachment into habitats used by
lesser prairie-chickens, further causing fragmentation of suitable
habitat patches. Some mammalian species known to prey on lesser
prairie-chickens, such as red fox, raccoons, and striped skunks, have
greatly increased their distribution by dispersing along roads (Forman
and Alexander 1998, p. 212; Forman 2000, p. 33; Frey and Conover 2006,
pp. 1114-1115).
[[Page 20052]]
Traffic noise from roads may indirectly impact lesser prairie-
chickens. Because lesser prairie-chickens depend on acoustical signals
to attract females to leks, noise from roads, oil and gas development,
wind turbines, and similar human activity may interfere with mating
displays, influencing female attendance at lek sites and causing young
males not to be drawn to the leks. Within a relatively short period,
leks can become inactive due to a lack of recruitment of new males to
the display grounds.
Roads also may influence lesser prairie-chicken dispersal, likely
dependent upon the volume of traffic, and thus disturbance, associated
with the road. However, roads generally do not constitute a significant
barrier to dispersal unless they are large, multiple-land roads. Lesser
prairie-chickens have been shown to avoid areas of suitable habitat
near larger, multiple-lane, paved roads (Pruett et al. 2009a, pp. 1256,
1258). Generally, roads were between 4.1 and 5.3 times less likely to
occur in areas used by lesser prairie-chickens than areas that were not
used and can influence habitat and nest site selection (Hagen et al.
2011, pp. 68, 71-72). Lesser prairie-chickens are thought to avoid
major roads due to disturbance caused by traffic volume and, perhaps
behaviorally, to avoid exposure to predators that may use roads as
travel corridors. Similar behavior has been documented in sage grouse
(Oyler-McCance et al. 2001, p. 330). Wisdom et al. (2011, p. 467)
examined factors believed to have contributed to extirpation of sage
grouse in areas scattered throughout the entire species' historical
range and found that extirpated range contained almost 27 times the
human density, was 60 percent closer to highways, and had 25 percent
higher density of roads, in contrast to occupied range.
Roads also can cause direct mortality due to collisions with
automobiles and possibly increased predation. Although individual
mortality resulting from collisions with moving vehicles does occur,
the mortalities typically are not monitored or recorded. Therefore we
cannot determine the importance of direct mortality from roads on
lesser prairie-chicken populations.
Using the data layers provided in StreetMap USA, a product of ESRI
Corporation and intended for use with ArcGIS, we estimated the scope of
the impact of roads on lesser prairie-chickens. Within the entire
historical range, there are 622,061 km (386,581 mi) of roads. This
figure includes major Federal and state highways as well as county
highways and smaller roads. Within the estimated occupied range,
approximately 81,874 km (50,874 mi) of roads have been constructed. We
also used topographically integrated geographic encoding and
referencing (TIGER) files available from the U.S. Census Bureau to
conduct a similar analysis of the impact of roads. These files, dated
2007, are more current than the information provided in StreetMap USA.
Within the historical range in 2007 there was a total of 642,860 km
(399,454.8 mi) of roads within the historical range. Of these roads,
about 84,531 km (52,525.3 mi) were located within the estimated
occupied range. More detailed examination of the roads in the estimated
occupied range revealed there were about 2,386 km (1,482.8 mi) of
primary roads, 2,002 km (1,244.3 mi) of secondary roads, and 80,142 km
(49,798.2 mi) of local or rural roads. Density (number per unit area)
of roads within the estimated occupied range was 1.04 km of road per
square km (1.68 mi of road per sq mi). The density of primary roads was
0.03 km of road per square km (0.05 mi of road per sq mi) and for
secondary roads was 0.02 km of road per square km (0.04 mi of road per
sq mi). The density of local and rural roads was highest at 0.99 km of
road per square km (1.59 mi of road per sq mi). Although we do not have
similar information for lesser prairie-chickens, Knick et al. (2013,
entire) found that road densities were particularly important in
assessing the value of habitat for greater sage grouse. The most
valuable sage grouse habitats had densities of secondary roads that
were below 1.0 km per sq km, highway densities below 0.05 km per sq km,
and interstate highway densities at or below 0.01 km per sq km (Knick
et al. 2013, p. 1544). Ninety-three percent of the active leks were
located in areas where interstate highway densities were less than 0.01
km/sq km (Knick et al. 2013, p. 1544).
While we do not anticipate significant expansion of the number or
distance of existing roads in the near or longterm, these roads have
already contributed to significant habitat fragmentation within both
the estimated historical and occupied range of the lesser prairie-
chicken. Assigning buffer values, as described in the rangewide plan
(Van Pelt et al. 2013, p. 95), to the existing roads within the
estimated occupied range provides an estimate of the amount of habitat
that has been lost to the lesser prairie-chicken, either by
construction, displacement or both. These buffer distances are 500 m
(1,640 ft) for primary roads, 67 m (220 ft) for secondary roads, and 10
m (33 ft) for local, rural roads. The total habitat impacted by all
types of roads within the estimated occupied range is 402,739.4 ha
(995,189.3 ac). The fragmentation caused by roads in combination with
other causes of fragmentation described in this final listing rule
contributes to the further reduction of usable habitat available to
support lesser prairie-chicken populations. The resultant fragmentation
is detrimental to lesser prairie-chickens because they rely on large,
expansive areas of contiguous rangeland and grassland to complete their
life cycle.
Although the best available information does not allow us to
predict the number or distance of new roads that will exist into the
future, we do not anticipate that the number or distance of primary and
secondary roads will increase significantly in the future. However, we
do anticipate that increasing human populations within the estimated
occupied range, as discussed previously, will lead to increased traffic
and road noise on the roads that do exist. Consequently, roads that are
already being avoided by lesser prairie-chickens will continue to be
barriers, and increasing traffic volumes will lead to additional roads
being avoided, further fragmenting an already highly fragmented
landscape. Additionally, Pitman et al. (2005, p. 1267) believes roads
served as travel corridors for predators and may increase the impact of
predation on lesser prairie-chickens (see section on Predation below).
In summary, roads occur throughout the range of the lesser prairie-
chicken and contribute to the threat of cumulative habitat
fragmentation to the species.
Petroleum Production
Petroleum production, primarily oil and gas development, is
occurring over much of the estimated historical and occupied range of
the lesser prairie-chicken. Oil and gas development involves activities
such as surface exploration, exploratory drilling, field development,
facility construction, and operation and maintenance. Ancillary
facilities can include compressor stations, pumping stations, and
electrical generators. Activities such as well pad construction,
seismic surveys, access road development, power line construction, and
pipeline corridors can directly impact lesser prairie-chicken habitat.
Indirect impacts from noise, gaseous emissions, and human presence also
influence habitat quality in oil and gas development areas. These
activities affect lesser prairie-chickens by
[[Page 20053]]
disrupting reproductive behavior (Hunt and Best 2004, p. 41) and
through habitat fragmentation and conversion (Hunt and Best 2004, p.
92). Smith et al. (1998, p. 3) observed that almost one-half, 13 of 29,
of the abandoned leks examined in southeastern New Mexico in an area of
intensive oil and gas development had a moderate to high level of
noise. Hunt and Best (2004, p. 92) found that abandoned leks in
southeastern New Mexico had more active wells, more total wells, and
greater length of access road than active leks. They concluded that
petroleum development at intensive levels, with large numbers of wells
in close proximity to each other necessitating large road networks and
an increase in the number of power lines, is likely not compatible with
life-history requirements of lesser prairie-chickens (Hunt and Best
2004, p. 92).
Impacts from oil and gas development and exploration is thought to
be the primary reason responsible for the species' near absence
throughout previously occupied portions of the Carlsbad BLM unit in
southeastern New Mexico (Belinda 2003, p. 3). This conclusion is
supported by research examining lesser prairie-chicken losses over the
past 20 years on Carlsbad BLM lands (Hunt and Best 2004, pp. 114-115).
Those variables associated with oil and gas development explained 32
percent of observed lek abandonment (Hunt and Best 2004) and the
consequent population extirpation.
Colorado currently ranks within the top ten States in both crude
oil and natural gas production. Oil and gas development began in
Colorado the late 1800s. Much of the development within the estimated
historical and occupied range of the lesser prairie-chicken occurs
within the Hugoton and Denver Basin fields. Since 1995 the number of
drilling permits issued annually has steadily grown from 1,002 in 1995
to 8,027 in 2008 (Dennison 2009). However, 84 percent of that activity
is located in only six counties that lie outside of the estimated
occupied range. Some development is anticipated in Baca County,
Colorado, although the timeframe for initiation of those activities is
uncertain (CPW 2007, p. 2). The State of Colorado, Oil and Gas
Conservation Commission also has established rules that provide some
protection to the lesser prairie-chicken from oil and gas development
in this State. A full list of those measures are provided in the
rangewide plan (Van Pelt et al. 2013, pp. 6-8) and include a
requirement to solicit review by the CPW prior to development in an
effort to avoid and minimize impacts to the lesser prairie-chicken.
Other measures include timing and distance stipulations, including a
provision to avoid development within 3.5 km (2.2 mi) of an active lek.
Kansas is one of the top ten oil producing States in the Nation and
is within the top 12 States in Natural gas production. Between 1995 and
2010, over 37.2 million barrels of oil were produced in Kansas (Circle
Star Energy 2014). The major oil and gas fields (Hugoton and Panoma) in
Kansas primarily occur in the southwestern corner and central regions
of the State, overlapping large portions of the estimated historic and
occupied ranges of the lesser prairie-chicken. Gas development is the
primary activity in the southwestern corner with oil being primary in
the central region. In the central region of Kansas, development of the
Mississippian Lime Play using hydraulic fracturing techniques has
revived oil and gas development in the region. The Kansas Department of
Commerce has stated that potentially hundreds of wells could be drilled
in this region in the next 20 to 30 years (Kansas Department of
Commerce 2014). Some gas development also occurs in the central region
of the State.
New Mexico currently ranks in the top ten States in the Nation for
production of both crude oil and natural gas (U.S. Energy Information
Administration 2014). Within the range of the lesser prairie-chicken,
much of the oil and gas development occurs on lands administered by the
BLM. In the BLM's Special Status Species Record of Decision and
approved Resource Management Plan Amendment (RMPA), some protections
for the lesser prairie-chicken on BLM lands in New Mexico are provided
by reducing the number of drilling locations, decreasing the size of
well pads, reducing the number and length of roads, reducing the number
of powerlines and pipelines, and implementing best management practices
for development and reclamation (BLM 2008, pp. 5-31). The RMPA provides
guidance for management of approximately 344,000 ha (850,000 ac) of
public land and 121,000 ha (300,000 ac) of Federal minerals below
private or state lands in Chaves, Eddy, Lea, and Roosevelt Counties in
New Mexico. Implementation of these restrictions, particularly
curtailment of new mineral leases, is concentrated in the Core
Management and Primary Population Areas (BLM 2008, pp. 9-11). The Core
Management and Primary Population Areas are located in the core of the
lesser prairie-chicken estimated occupied range in New Mexico. The
effect of these best management practices on the population of the
lesser prairie-chicken is unknown, particularly considering about
33,184 ha (82,000 ac) have already been leased in those areas (BLM
2008, p. 8). The plan stipulates that measures designed to protect the
lesser prairie-chicken and dunes sagebrush lizard may not allow
approval of all spacing unit locations or full development of the lease
(BLM 2008, p. 8).
Oklahoma currently ranks in the top five States in the Nation for
production of both crude oil and natural gas (U.S. Energy Information
Administration 2014). In Oklahoma, oil and gas exploration statewide
continues at a high level. Since 2002, the average number of active
drilling rigs in Oklahoma has steadily risen (Boyd 2009, p. 1). Since
2004, the number of active drilling rigs has remained above 150,
reflecting the highest level of sustained activity since the `boom'
years from the late 1970s through the mid-1980s in Oklahoma (Boyd 2007,
p. 1). The Oklahoma Department of Wildlife Conservation worked with the
Oklahoma Independent Petroleum Association to address potential impacts
of oil and gas development on the lesser prairie-chicken. Through this
effort, a set of voluntary best management practices, such as
minimizing surface disturbance and removal of unneeded equipment, have
been developed (Van Pelt et al. 2013, p. 60).
Texas currently ranks as the top State in the Nation for production
of both crude oil and natural gas (U.S. Energy Information
Administration 2014). In some areas within the estimated occupied
range, the scope of development has increased significantly. For
example, the amount of habitat fragmentation due to oil and gas
extraction in the Texas panhandle and western Oklahoma associated with
the Buffalo Wallow oil and gas field within the Granite Wash formation
of the Anadarko Basin has steadily increased over time. In 1982, the
rules for the Buffalo Wallow field in Hemphill and Wheeler counties,
Texas allowed one well per 130 ha (320 ac). In late 2004, the Texas
Railroad Commission changed the field rule regulations for the Buffalo
Wallow oil and gas field to allow oil and gas well spacing to a maximum
density of one well per 8 ha (20 ac) (Rothkopf et al. 2011, p. 1). When
fully developed at this density, this region of the Texas panhandle,
which overlaps portions of the estimated occupied range, will have
experienced a 16-fold increase in habitat fragmentation in comparison
with the rates allowed prior to 2004.
[[Page 20054]]
Oil and gas development and exploration is ongoing in all five
lesser prairie-chicken States. Based on the information available to
us, none of the States, with the exception of Colorado, has implemented
specific regulatory measures to address impacts of oil and gas
development on the lesser prairie-chicken. In New Mexico, much of the
oil and gas development within the estimated historic and occupied
range is regulated by the BLM. Where Federal minerals occur outside of
New Mexico and within the estimated occupied range, BLM has implemented
timing, noise, and distance stipulations that primarily provide
protections during the lekking season but do little to protect nesting
hens and the broods. We attempted to assess the extent of oil and gas
development using available information from the State oil and gas
regulatory agencies within the five State range of the lesser prairie-
chicken. Although we do not have access to information on oil and gas
activity beyond 2008, the data provide a fairly good assessment of
development activity before 2008. We identified 670,509 existing oil
and gas wells within the historical range and of those wells, 53,205
oil and gas wells existed within the estimated occupied range. The
rangewide plan (Van Pelt et al. 2013, pp. 132-134) estimated 68,716
active wells exist within the EOR +10, based on data from 2010 to 2013.
If we apply a 200 m buffer to those wells, as used in the rangewide
plan (Van Pelt et al. 2013, p. 95), and remove any overlap from our
analysis, an estimated 516,000 ha (1.27 million ac) of habitat within
the estimated occupied range was impacted by oil and gas development by
2008. The buffers established in the rangewide plan were based on the
best available science and the professional judgment of the members of
the Interstate Working Group Science team, which included
representation from the Service, U.S. Geological Survey, Natural
Resources Conservation Service, State Fish and Wildlife Agencies,
public universities, private conservation organizations and private
consultants.
We lacked data from which we could independently project oil and
gas development into the future. However, the rangewide plan (Van Pelt
et al. 2013, pp. 138) provided a high and low projection of oil and gas
development within the EOR +10 for 10, 20 and 30 years into the future.
Within 30 years, they estimate that about 122,639 new wells under a low
price scenario and 179,416 new wells under a high price scenario could
be developed within the EOR +10.
Wastewater pits associated with energy development are not
anticipated to be a major threat to lesser prairie-chickens primarily
due to the presence of infrastructure and the lack of suitable cover
near these pits. In formations with high levels of hydrogen sulfide
gas, the presence of this gas can cause mortality.
In summary, infrastructure associated with current petroleum
production contributes to the ongoing habitat fragmentation within the
estimated occupied range of the lesser prairie-chicken. Reliable
information about future trends for petroleum production indicates that
this impact will continue into the future. Habitat impacts, based on
our estimates, as provided above, and those of WAFWA (Van Pelt et al.
2013, p. 95), could be in excess of a million of acres throughout the
estimated occupied range.
Predation
Lesser prairie-chickens have coevolved with a variety of predators,
but none are lesser prairie-chicken specialists. Prairie falcon (Falco
mexicanus), northern harrier (Circus cyaneus), Cooper's hawk (Accipiter
cooperii), great-horned owl (Bubo virginianus), other unspecified birds
of prey (raptors), and coyote (Canis latrans) have been identified as
predators of lesser prairie-chicken adults and chicks (Davis et al.
1979, pp. 84-85; Merchant 1982, p. 49; Haukos and Broda 1989, pp. 182-
183; Giesen 1994a, p. 96). Predators of nests and eggs also include
Chihuahuan raven (Corvus cryptoleucus), striped skunk (Mephitis
mephitis), ground squirrels (Spermophilus spp.), and bullsnakes
(Pituophis melanoleucus), as well as coyotes and badgers (Taxidea
taxus) (Davis et al. 1979, p. 51; Haukos 1988, p. 9; Giesen 1998, p.
8).
Lesser prairie-chicken predation varies in both form and frequency
throughout the year. In Kansas, Hagen et al. (2007, p. 522) attributed
about 59 percent of the observed mortality of female lesser prairie-
chickens to mammalian predators and between 11 and 15 percent,
depending on season, to raptors. Coyotes were reported to be
responsible for 64 percent of the nest depredations observed in Kansas
(Pitman et al. 2006a, p. 27). Observed mortality of male and female
lesser prairie-chickens associated with raptor predation reached 53
percent in Oklahoma and 56 percent in New Mexico (Wolfe et al. 2007, p.
100). Predation by mammals was reported to be 47 percent in Oklahoma
and 44 percent in New Mexico (Wolfe et al. 2007, p. 100). In Texas,
over the course of three nonbreeding seasons, Boal and Pirius (2012, p.
8) assessed cause-specific mortality for 13 lesser prairie-chickens.
Avian predation was identified as the cause of death in 10 of those
individuals, and mammalian predation was responsible for 2 deaths. The
cause of death could not be identified in one of those individuals.
Behney et al. (2012, p. 294) suspected that mammalian and reptilian
predators had a greater influence on lesser prairie-chicken mortality
during the breeding season than raptors.
Predation is a naturally occurring phenomenon and generally does
not pose a risk to wildlife populations, including the lesser prairie-
chicken, unless the populations are extremely small or have an abnormal
level of vulnerability to predation. The lesser prairie-chicken's
cryptic plumage and behavioral adaptations allow the species to persist
under normal predation pressures. Birds may be most susceptible to
predation while on the lek when birds are more conspicuous. Both Patten
et al. (2005b, p. 240) and Wolfe et al. (2007, p. 100) reported that
raptor predation increased coincident with lek attendance. Patten et
al. (2005b, p. 240) stated that male lesser prairie-chickens are more
vulnerable to predation when exposed during lek displays than they are
at other times of the year and that male lesser prairie-chicken
mortality was chiefly associated with predation. However, during 650
hours of lek observations in Texas, raptor predation at leks was
considered to be uncommon and an unlikely factor responsible for
declines in lesser prairie-chicken populations (Behney et al. 2011, pp.
336-337). But Behney et al. (2012, p. 294) observed that the timing of
lekking activities in their study area corresponded with the lowest
observed densities of raptors and that lesser prairie-chickens contend
with a more abundant and diverse assemblage of raptors in other
seasons.
Predation and related disturbance of mating activities by predators
may impact reproduction in lesser prairie-chickens. For females,
predation during the nesting season likely would have the most
significant impact on lesser prairie-chicken populations, particularly
if that predation resulted in total loss of a particular brood.
Predation on lesser prairie-chicken may be especially significant
relative to nest success. Nest success and brood survival of greater
prairie-chickens accounted for most of the variation in population
finite rate of increase (Wisdom and Mills 1997, p. 308). Bergerud
(1988, pp. 646, 681, 685) concluded that population changes in many
grouse species are driven by
[[Page 20055]]
changes in breeding success. An analysis of Attwater's prairie-chicken
supported this conclusion (Peterson and Silvy 1994, p. 227).
Demographic research on lesser prairie-chicken in southwestern Kansas
confirmed that changes in nest success and chick survival, two factors
closely associated with vegetation structure, have the largest impact
on population growth rates and viability (Hagen et al. 2009, p. 1329).
Rates of predation on lesser prairie-chicken likely are influenced
by certain aspects of habitat quality such as fragmentation or other
forms of habitat degradation (Robb and Schroeder 2005, p. 36). As
habitat fragmentation increases, suitable habitats become more
spatially restricted and the effects of terrestrial nest predators on
grouse populations may increase (Braun et al. 1978, p. 316). In a study
on Attwater's prairie-chicken, Horkel et al. (1978, p. 239) observed
that artificial nests located within 46 m (150 ft) of a road or mown
pipeline rights-of-way were less successful than artificial nests
located further away from these features. They concluded that these
fragmenting features served as activity centers and travel lanes for
predators and contributed to increased predator activity and decreased
nest success in proximity to these features (Horkel et al. 1978, p.
240). Nest predators typically have a positive response (e.g.,
increased abundance, increased activity, and increased species
richness) to fragmentation, although the effects are expressed
primarily at the landscape scale (Stephens et al. 2003, p. 4).
Similarly, as habitat quality decreases through reduction in vegetative
cover due to grazing or herbicide application, predation of lesser
prairie-chicken nests, juveniles, and adults are all expected to
increase. For this reason, ensuring adequate shrub cover and removing
raptor perches such as trees, power poles, and fence posts may lower
predation more than any conventional predator removal methods (Wolfe et
al. 2007, p. 101). As discussed at several locations within this
document, existing and future development of transmission lines,
fences, and vertical structures will either contribute to additional
predation on lesser prairie-chickens or cause areas of suitable habitat
to be abandoned due to behavior avoidance by lesser prairie-chickens.
Increases in the encroachment of trees into the native prairies also
will contribute to increased incidence of predation by providing
additional perches for avian predators. Because predation has a strong
relationship with certain anthropogenic factors, such as fragmentation,
vertical structures, and roads, continued development is likely to
increase the effects of predation on lesser prairie-chickens beyond
natural levels. As a result, predation is likely to contribute to the
declining population of the species.
Disease
Giesen (1998, p. 10) provided no information on ectoparasites or
infectious diseases in lesser prairie-chicken, although several
endoparasites, including nematodes and cestodes, are known to infect
the species. In Oklahoma, Emerson (1951, p. 195) documented the
presence of the external parasites (biting lice--Order Mallophaga)
Goniodes cupido and Lagopoecus sp. in an undisclosed number of lesser
prairie-chickens. Between 1997 and 1999, Robel et al. (2003, p. 342)
conducted a study of helminth parasites in lesser prairie-chickens from
southwestern Kansas. Of the carcasses examined, 95 percent had eye worm
(Oxyspirura petrowi), 92 percent had stomach worm (Tetrameres sp.), and
59 percent had cecal worm (Subulura sp.) (Robel et al. 2003, p. 341).
No adverse impacts to the lesser prairie-chicken population they
studied were evident as a result of the observed parasite burden.
Addison and Anderson (1969, p. 1223) also found eyeworm (O. petrowi)
from a limited sample of lesser prairie-chickens in Oklahoma. The
eyeworm also has been reported from lesser prairie-chickens in Texas
(Pence and Sell 1979, p. 145). Pence and Sell (1979, p. 145) also
observed the roundworm Heterakis isolonche and the tapeworm Rhabdometra
odiosa from lesser prairie-chickens in Texas. Smith et al. (2003, p.
347) reported on the occurrence of blood and fecal parasites in lesser
prairie-chickens in eastern New Mexico. Eight percent of the examined
birds were infected with Eimeria tympanuchi, an intestinal parasite,
and 13 percent were infected with Plasmodium pedioecetii, a hematozoan.
Stabler (1978, p. 1126) first reported Plasmodium pedioecetii in the
lesser prairie-chicken from samples collected from New Mexico and
Texas. In the spring of 1997, a sample of 12 lesser prairie-chickens
from Hemphill County, Texas, were tested for the presence of disease
and parasites. No evidence of viral or bacterial diseases,
hemoparasites, parasitic helminths, or ectoparasites was found (Hughes
1997, p. 2).
In southwestern Kansas, Hagen et al. (2002 entire) tested for the
presence of mycoplasmosis, a respiratory infection, in lesser prairie-
chickens. Although some birds tested positive for antibodies to
Mycoplasma meleagridis, M. synoviae, and M. gallisepticum, all were at
rates less than 10 percent and no infection was confirmed (Hagen et al.
2002, p. 708). However, lesser prairie-chickens testing positive should
be considered potential carriers of mycoplasmosis (Hagen et al., 2002,
p. 710). Infections may be transmitted most commonly during winter and
spring when lesser prairie-chickens are likely to be grouped together
to forage or conduct breeding activity.
Peterson et al. (2002, p. 835) reported on an examination of 24
lesser prairie-chickens from Hemphill County, Texas, for several
disease agents. Lesser prairie-chickens were seropositive for both the
Massachusetts and Arkansas serotypes of avian infectious bronchitis, a
type of coronavirus. All other tests were negative.
Reticuloendotheliosis is a viral disease of poultry that has been
found to cause mortality in captive Attwater's prairie-chickens and
greater prairie-chickens (Drew et al. 1998, entire). Symptoms include
immunosuppression, reduced body size and tumors that can result in
significant morbidity and mortality (Bohls et al. 2006a, p. 613).
Researchers surveyed blood samples from 184 lesser prairie-chickens
from three States during 1999 and 2000, for the presence of
reticuloendotheliosis. All samples were negative, suggesting that
reticuloendotheliosis may not be a serious problem for most wild
populations of lesser prairie-chicken (Wiedenfeld et al. 2002, p. 143).
A vaccine has recently been developed that, while not preventing
infection, provided partial protection from reticuloendotheliosis in
captive Attwater's prairie-chicken (Drechsler et al. 2013, pp. 258-
259). This vaccine has not yet been tested on lesser prairie-chickens
to our knowledge.
The impact of West Nile virus on lesser prairie-chickens is
unknown. Recently scientists at Texas Tech University detected West
Nile virus in a small percentage (1.3 percent) of the lesser prairie-
chicken blood samples they analyzed. Other grouse, such as ruffed
grouse (Bonasa umbellus), have been documented to harbor West Nile
virus infection rates similar to some corvids (crows, jays, and
ravens). For 130 ruffed grouse tested in 2000, all distant from known
West Nile virus epicenters, 21 percent tested positive. This was
remarkably similar to American crows (Corvus brachyrhynchos) and blue
jays (Cyanocitta cristata) (23 percent for each species), species with
known susceptibility to West Nile virus (Bernard et al. 2001, p. 681).
The IPCC
[[Page 20056]]
(2007, p. 51) suggests that the distribution of some disease vectors,
such as mosquitos (Culex spp.) that carry West Nile virus, may change
as a result of climate change. Mosquitoes are also known to transmit
the reticuloendotheliosis virus (Bohls et al. 2006b, p. 193). However,
we have no specific information suggesting that West Nile virus or any
known disease may become problematic for the lesser prairie-chicken as
a result of climate change.
Although parasites and diseases have the potential to influence
population dynamics, the incidence of disease or parasite infestations
in regulating populations of the lesser prairie-chicken is unknown. The
Lesser Prairie-Chicken Interstate Working Group (Mote et al. 1999, p.
12) concluded that, while density-dependent transmission of disease was
unlikely to have a significant effect on lesser prairie-chicken
populations, a disease that was transmitted independently of density
could have drastic effects. Further research is needed to establish
whether parasites limit prairie grouse populations. Peterson (2004, p.
35) urged natural resource decisionmakers to be aware that macro- and
micro-parasites cannot be safely ignored as populations of species such
as the lesser prairie-chicken become smaller, more fragmented, and
increasingly vulnerable to the effects of disease. A recent analysis of
the degree of threat to prairie grouse from parasites and infectious
disease concluded that microparasitic infections that cause high
mortality across a broad range of galliform (wildfowl species such as
turkeys and grouse) hosts have the potential to extirpate small,
isolated prairie grouse populations (Peterson 2004, p. 35).
Some degree of impact from parasites and disease is a naturally
occurring phenomenon for most wildlife species and is one element of
compensatory mortality (the phenomenon that various causes of mortality
in wildlife tend to balance each other, allowing the total mortality
rate to remain constant) that operates among many species. However,
there is no information that indicates parasites or disease are
causing, or contributing to, the decline of any lesser prairie-chicken
populations, and, at this time, we have no basis for concluding that
disease or parasite loads are a threat to any lesser prairie-chicken
populations. Consequently, we do not consider disease or parasite
infections to be a significant factor in the decline of the lesser
prairie-chicken. However, should populations continue to decline or
become more isolated by fragmentation, even small changes in habitat
abundance or quality could have a more significant influence on the
impact of parasites and diseases to the lesser prairie-chicken.
Hunting and Other Forms of Recreational, Educational, or Scientific Use
In the late 19th century, lesser prairie-chickens were subject to
market hunting (Jackson and DeArment 1963, p. 733; Fleharty 1995, pp.
38-45; Jensen et al. 2000, p. 170). Harvest throughout the species'
estimated historical range has been regulated since approximately the
turn of the 20th century (Crawford 1980, pp. 3-4). Currently, the
lesser prairie-chicken is classified as a game species in Kansas, New
Mexico, Oklahoma, and Texas, although authorized harvest is allowed
only in Kansas. The lesser prairie-chicken has been listed as a
threatened species in Colorado, eliminating harvest of the species
under the State's Nongame and Endangered or Threatened Species
Conservation Act since 1973. In March of 2009, Texas adopted a
temporary, indefinite suspension of their current 2-day season until
lesser prairie-chicken populations recover to huntable levels.
Previously in Texas, lesser prairie-chicken harvest was not allowed
except on properties with an approved wildlife management plan
specifically addressing the lesser prairie-chicken. When both Kansas
and Texas allowed lesser prairie-chicken harvest, the total annual
harvest for both States was fewer than 1,000 birds annually.
In New Mexico, the lesser prairie-chicken was legally hunted until
1996 (Hunt 2004, p. 39). The annual harvest in the 1960s averaged about
1,000 birds, but harvest declined to only 130 birds in 1979. Harvest
rebounded a few years later peaking in 1987 and 1988 when average
harvest was about 4,000 birds (Hunt 2004, p. 39). Harvest subsequently
declined through the early 1990s.
In Kansas, the current bag limit is one lesser prairie-chicken
daily south of Interstate 70 and two lesser prairie-chickens north of
Interstate 70. The season typically begins in early November and runs
through the end of December in southwestern Kansas. In the northwestern
portion of the State, the season typically extends through the end of
January. During the 2006 season, hunters in Kansas expended 2,020
hunter-days and harvested approximately 340 lesser prairie-chickens. In
2010, 2,863 hunter-days were expended and an estimated 633 lesser
prairie-chickens were harvested in Kansas (Pitman 2012a). Given the low
number of lesser prairie-chickens harvested per year in Kansas relative
to the population size of lesser prairie-chickens, the statewide
harvest is probably insignificant at the population level. There are no
recent records of unauthorized harvest of lesser prairie-chickens in
Kansas (Pitman 2012b).
Two primary hypotheses exist regarding the influence of hunting on
harvested populations--hunting mortality is either additive to other
sources of mortality or nonhunting mortality compensates for hunting
mortality, up to some threshold level. The compensatory hypothesis
essentially implies that harvest by hunting removes only surplus
individuals, and individuals that escape hunting mortality will have a
higher survival rate until the next reproductive season. Both Hunt and
Best (2004, p. 93) and Giesen (1998, p. 11) do not believe hunting has
an additive mortality on lesser prairie-chickens, although, in the
past, hunting during periods of low population cycles may have
accelerated declines (Taylor and Guthery 1980b, p. 2). However, because
most remaining lesser prairie-chicken populations are now very small
and isolated, and because they naturally exhibit a clumped distribution
on the landscape, they are likely vulnerable to local extirpations
through many mechanisms, including harvest by humans. Braun et al.
(1994, p. 435) called for definitive experiments that evaluate the
extent to which hunting is additive at different harvest rates and in
different patch sizes. They suggested conservative harvest regimes for
small or fragmented grouse populations because fragmentation likely
decreases the resilience of populations to harvest. Sufficient
information to determine the rate of localized harvest pressure is
unavailable and, therefore, the Service cannot determine whether such
harvest contributes to local population declines. We do not consider
hunting to be a threat to the species at this time. However, as
populations of lesser prairie-chickens become smaller and more isolated
by habitat fragmentation, their resiliency to the influence of hunting
pressure will decline, likely increasing the degree of threat that
hunting may pose to the species.
An additional activity that has the potential to negatively affect
individual breeding aggregations of lesser prairie-chickens is the
growing occurrence of public and guided bird watching tours of leks
during the breeding season. The site-specific impact of recreational
observations of lesser prairie-chicken at leks is currently unknown but
daily human disturbance could reduce mating activities, possibly
leading to a
[[Page 20057]]
reduction in total production. However, disturbance effects are likely
to be minimal at the population level if disturbance is avoided by
observers remaining in vehicles or blinds until lesser prairie-chickens
naturally disperse from the lek and observations are confined to a
limited number of days and leks. Solitary leks comprising fewer than
ten males are most likely to be affected by repeated recreational
disturbance. Suminski (1977, p. 70) strongly encouraged avoidance of
activities that could disrupt nesting activities. Research is needed to
quantify this potential threat to local populations of lesser prairie-
chickens.
Research activities, such as roadside surveys and flush counts,
that generally tend to rely on passive sampling rather than active
handling of the birds are not likely to substantially impact the lesser
prairie-chicken. When birds are flushed, some increased energy
expenditure or exposure to predation may occur, but the impacts are
anticipated to be minor and of short duration. Studies that involve
handling of adults, chicks and eggs, particularly those involving the
use of radio transmitters, also may cause increased energy expenditure,
predation exposure or otherwise impact individual birds. However such
studies typically occur at a relatively small, localized scale and are
not likely to cause a direct impact to the population as a whole. Such
studies are usually of short duration, lasting no more than a few
years.
In summary, it is possible that harvest of lesser prairie-chickens
through sport hunting might be contributing to a decline of some
populations, but the best available information does not show whether
this is actually occurring and we have no basis on which to estimate
whether hunting is contributing to decline in some areas. However, as
populations continue to decline and become more fragmented, the
influence of sport harvest likely will increase and could become a
threat in the future. Public viewing of leks tends to be limited,
primarily due to a general lack of public knowledge of lek locations
and difficulty accessing leks located on private lands. Observations by
bird watchers are likely to be very limited in extent and bird
watchers, as a group, generally tend to minimize disturbance to birds
as they conduct their activities. We expect the range States will
continue to conduct annual lek counts, which contributes to a temporary
disturbance when the birds are flushed during attempts to count birds
attending the leks. However these disturbances are intermittent and do
not occur repeatedly throughout the lekking period. Research on lesser
prairie-chickens may result in some capture and handling of the
species. Capture-induced stress may occur and could lead to isolated
instances of mortality or injury to individual birds. But such research
is not widespread and likely does not cause significant population-
level impacts. Research is not anticipated to result in loss of habitat
and is therefore not likely to lead to impacts from habitat
fragmentation. We are not aware of any other forms of utilization that
are negatively impacting lesser prairie-chicken populations. There is
currently no known, imminent threat of take attributed to collection or
illegal harvest for this species, consequently, we conclude that
overutilization at current population and harvest levels does not pose
a threat to the species.
Other Factors
A number of other factors, although they do not directly contribute
to habitat loss or fragmentation, can influence the survival of the
lesser prairie-chicken. These factors, in combination with habitat loss
and fragmentation, are likely to negatively influence the persistence
of the species.
Nest Parasitism and Competition by Exotic Species
Ring-necked pheasants (Phasianus colchicus) are nonnative species
that overlap the estimated occupied range of the lesser prairie-chicken
in Kansas and portions of Colorado, Oklahoma, Texas (Johnsgard 1979, p.
121), and New Mexico (Allen 1950, p. 106). Hen pheasants have been
documented to lay eggs in the nests of several bird species, including
lesser prairie-chicken and greater prairie-chicken (Hagen et al. 2002,
pp. 522-524; Vance and Westemeier 1979, p. 223; Kimmel 1987, p. 257;
Westemeier et al. 1989, pp. 640-641; Westemeier et al. 1998, 857-858).
Consequences of nest parasitism vary, and may include abandonment of
the host nest, reduction in number of host eggs, lower hatching
success, and parasitic broods (Kimmel 1987, p. 255). Because pheasant
eggs hatch in about 23 days, the potential exists for lesser prairie-
chicken hens to cease incubation, begin brooding, and abandon the nest
soon after the first pheasant egg hatches. Nests of greater prairie-
chickens parasitized by pheasants have been shown to have lower egg
success and higher abandonment than unparasitized nests, suggesting
that recruitment and abundance may be impacted (Westemeier et al. 1998,
pp. 860-861). Predation rates also may increase with incidence of nest
parasitism (Vance and Westemeier 1979, p. 224). Further consequences
are hypothesized to include the imprinting of the pheasant young from
the parasitized nest to the host species, and later attempts by male
pheasants to court females of the host species (Kimmel 1987, pp. 256-
257). Male pheasants have been observed disrupting the breeding
behavior of greater prairie-chickens on leks (Sharp 1957, pp. 242-243;
Follen 1966, pp. 16-17; Vance and Westemeier 1979, p. 222). In
addition, pheasant displays toward female prairie-chickens almost
always cause the female to leave the lek (Vance and Westemeier 1979, p.
222). Thus, an attempt by a male pheasant to display on a prairie-
chicken lek could disrupt the normal courtship activities of prairie-
chickens.
Few published accounts of lesser prairie-chicken nest parasitism by
pheasants exist (Hagen et al. 2002, pp. 522-524), although biologists
from KPWD, ODWC, Sutton Center, TPWD, and the Oklahoma Cooperative Fish
and Wildlife Research Unit have given more than 10 unpublished accounts
of such occurrences. Westemeier et al. (1998, p. 858) documented
statistically that for a small, isolated population of greater prairie-
chickens in Illinois, nest parasitism by pheasants significantly
reduced the hatchability of nests. They concluded that, in areas with
high pheasant populations, the survival of isolated, remnant flocks of
prairie-chicken may be enhanced by management intervention to reduce
nest parasitism by pheasants (Westemeier et al. 1998, p. 861). While
Hagen et al. (2002, p. 523) documented a rate of only 4 percent
parasitism (3 of 75 nests) of lesser prairie-chicken nests in Kansas,
the sample size was small and may not reflect actual impacts across
larger time and geographic scales, and precipitation gradients.
Competition with and parasitism by pheasants may be a potential factor
that could negatively affect vulnerable lesser prairie-chicken
populations at the local level, particularly if remaining native
rangelands become increasingly fragmented (Hagen et al. 2002, p. 524).
More research is needed to understand and quantify impacts of pheasants
on lesser prairie-chicken populations range wide.
Hybridization
The sympatric (overlapping) occupation of habitat and leks by
greater prairie-chickens and lesser prairie-chickens in a small 250,000
ha (617,000 ac) portion of central and northwestern Kansas may pose a
potential, but limited threat to the species in that region.
[[Page 20058]]
Hybridization between the two species could lead to introgression
(infiltration of the genes of one species into the gene pool of another
through repeated backcrossing) and reduced reproductive potential.
Hybrid crosses between greater and lesser prairie-chickens have been
produced in captivity and the first generation of offspring are
fertile; however, mating of second-generation hybrids produced a clutch
of 26 eggs, but only 11 eggs were fertile and only four of those eggs
hatched (Crawford 1978, p. 592). All four of those chicks died within
one week of unknown causes.
Prior to EuroAmerican settlement of the Great Plains, the
distributions of the greater and lesser prairie-chicken likely did not
overlap, although it is impossible to precisely determine their
presettlement distribution patterns (Johnsgard and Wood 1968, p. 174).
Following human settlement and initial cultivation of the prairies, the
distribution of the greater and lesser prairie-chicken expanded, at
least until the amount of cultivation was so extensive that some
populations could not persist due to inadequate amounts of native
grassland intermingled with cultivation (Johnsgard and Wood 1968, p.
177). As indicated by Sharpe (1968, pp. 51, 174), the historical
occurrence of lesser prairie-chickens in Nebraska was considered be the
result of a short-lived range expansion facilitated by human settlement
and cultivation of grain crops. As their ranges expanded, some overlap
of lesser and greater prairie-chickens occurred, primarily in
northwestern Kansas and southwestern Nebraska. Where the two species
came into contact, some natural hybridization likely occurred but the
frequency is unknown. As the range of the lesser prairie-chicken shrank
in response to expanding conversion of the prairie, the ranges of
lesser and greater prairie-chickens ceased to overlap, at least until
recently. Habitat restoration in northwestern Kansas, assisted by
successful planting of native grassland CRP since 1985, likely
facilitated the co-occupation of portions of their ranges. The ranges
of greater and lesser prairie-chickens now overlap within a seven
county region in Kansas (Bain and Farley 2002, p. 684).
In this seven county area, Bain and Farley (2002, p. 684) observed
12 birds from nine mixed leks containing both greater and lesser
prairie-chickens that appeared to be hybrids. These birds displayed
external characteristics, courtship behaviors and vocalizations that
were intermediate between the two species but they were unable to
confirm that these birds were actually hybrids (Bain and Farley 2002,
pp. 684-686).
Currently, the incidence of hybridization between greater prairie-
chickens and lesser prairie-chickens appears very low, less than 1
percent (309 individuals) of the estimated total population (MacDonald
et al. 2012, p. 21). The occurrence of hybridization also is restricted
to a small portion, about 250,000 ha (617,000 ac), of the overall
current range (Bain and Farley 2002, p. 684). Although the density of
leks within the area north of the Arkansas River in Kansas are high,
the density of mixed leks is much lower (MacDonald et al. 2012, p. 21).
These populations are largely dependent on fragmented tracts of CRP
lands, and lesser prairie-chicken populations may continue to expand
within this region depending on implementation of CRP projects and
stochastic environmental factors. Should greater prairie-chicken
populations in this region expand, increasing the extent of overlap in
their distributions, the incidence of hybridization also may increase.
Currently we are unable to predict how the incidence of hybridization
may change into the future. Additionally, the zone of hybridization may
decrease in size or cease to exist entirely if the extent of cropland
or suitable habitat changes in response to CRP. The zone of overlap
could increase with time if the lesser prairie-chicken occupied range
shifts northward, particularly in light of climate changes that may
occur within the next 100 years. If the zone of overlap expands, the
extent of hybridization may increase.
Currently, we have no information on how these apparent hybrid
individuals interact and compete in breeding on the lek. If the second
generation hybrids truly are not viable, as reported by Crawford (1978,
p. 592), the risk of introgression, should they be successful in
competing for mates, is low. However, the fertility of first and second
generation hybrid individuals has not been rigorously tested.
Theoretically, natural isolating mechanisms, such as appearance,
vocalization and courtship behavior would serve to minimize the
incidence of hybridization. However, as discussed in the ``Taxonomy''
section, speciation in lesser and greater prairie-chickens may be
incomplete and natural isolating mechanisms may not operate
effectively. Noise from human developments that may mask vocalizations
in lesser prairie-chickens, as previously discussed in the section on
influence of noise, also may impact the ability of females to detect
differences in vocalizations between lesser prairie-chickens and their
hybrids. Additionally, low population density may increase the
susceptibility of lesser prairie-chickens to hybridization, primarily
within the zone of overlap, and could exacerbate the potentially
negative effects of hybridization. Hybridization is a particularly
important issue for species that are rare and both fragmentation and
habitat modification are significant factors that can contribute to
increased rates of hybridization in some species (Rhymer and Simberloff
1996, pp. 83, 103; Allendorf et al. 2001, p. 613).
Presently, the immediate and long-term influence of hybridization
on the species is unknown, although Johnsgard (2002, p. 32) did not
consider current levels of hybridization to be genetically significant.
Similarly, Johnson (2008, pp. 170-171) estimated that the rate of gene
flow between lesser and greater prairie chickens was very low. Because
the current extent, both numerically and areally, of hybridization
appears very small, we currently do not consider hybridization to be a
threat. Interbreeding on the mixed leks could result in some wasted
reproductive effort but significant demographic effects are not
expected at current levels. However, continued monitoring and
additional investigation of hybridization between greater and lesser
prairie-chickens is encouraged. Should the zone of overlap continue to
expand, hybridization could become a threat with a significant impact
on the lesser prairie-chicken.
Genetic Risks, Small Population Size and Lek Mating System
Anthropogenic habitat deterioration and fragmentation, as
previously discussed in this rule, not only drives range contractions
and population extinctions but also may have significant genetic and,
thus, evolutionary consequences for the surviving populations. Genetic
risks, such as reduced reproductive success, are an important concern
for lesser prairie-chickens, particularly considering the extensive
reduction in abundance and occupied range that has occurred since
EuroAmerican settlement of the Great Plains, and such risks often
impact species well before they are driven to extinction (Spielman et
al. 2004, p. 15264; Frankham 2005, pp. 134-135). Although we lack
precise estimates of lesser prairie-chicken abundance and distribution
prior to human settlement, we can infer from the estimates provided in
the literature (previously discussed in section on Historical Range and
Distribution) that populations were considerably larger and more widely
distributed than they
[[Page 20059]]
are at present. Typically, these larger populations have more genetic
diversity and are less vulnerable to extinction than smaller
populations (Frankham 1996, pp. 1503-1507; Spielman et al. 2004, p.
15261; Frankham 2005, p. 132; Willi et al. 2006, entire).
As surviving populations become more isolated due to fragmentation
and habitat loss, the movement of genetic information (gene flow)
between those populations declines, leading to loss of genetic
diversity and variability. Pruett et al. (2009b, p. 258) concluded that
lesser prairie-chicken populations were historically connected, as
evidenced by the lack of morphological variation across the range and
availability of genetic information which suggests that the populations
were contiguous and gene flow occurred among the extant populations.
Considering increased levels of fragmentation can constrain dispersal
in lesser prairie-chickens, low levels of dispersal may contribute to
increased relatedness in both males and females at some lek sites.
However, an analysis of genetic data collected in the early 2000s from
Colorado, Kansas, New Mexico and Oklahoma did not indicate that
population declines and habitat fragmentation apparent at that time had
created any barriers to lesser prairie-chicken dispersal (Hagen et al.
2010, p. 35).
A number of harmful effects, such as reduced reproductive success
or disease resistance, can have a genetic link and, over time, the loss
of genetic variation and diversity allows these deleterious effects to
become more prevalent as population sizes decline or isolation
increases. Inbreeding occurs when the number of mates from which to
choose become limited, increasing relatedness among individuals and
contributing to a reduction in genetic variability. Inbreeding can
reduce reproductive fitness and survival and increase extinction risk
(Spielman et al. 2004, pp. 15261, 15263; Frankham 2005, pp. 132-133,
136). Other genetic factors such as mutation and genetic drift (change
in the genetic composition of a population due to chance events) also
can influence genetic diversity and may contribute to increased
extinction risk over long time spans. A loss of genetic diversity also
may reduce the ability of individuals and populations to respond, or
adapt, to changing environmental conditions, potentially impacting
long-term stability and viability (Willi et al. 2006, pp. 447-450;
Hughes et al. 2008, pp. 615-617, 620; Frankham 2005, p. 135). As
populations decline, they become more sensitive to random demographic,
environmental, and catastrophic (non-genetic) events. Factors such as
drought, disease or predation can exert a more substantial influence
over small populations. Even small populations that are growing can
succumb to random changes in birth or survival rates that may drive a
population to extinction. The small, fragmented lesser prairie-chicken
populations that currently exist over portions of the estimated
occupied range have an increased likelihood that such harmful effects
already may be, or soon will be, occurring.
These genetic risks, and their suite of associated harmful effects,
may be amplified by the lek mating system characteristic of prairie
grouse (Corman 2011, pp. 34-35). When male prairie chickens select a
site for displaying, several factors such as high visibility, good
auditory projection, and a lack of ambient noise are known to influence
selection of lek sites by prairie chickens, and these same factors
likely help aid females in locating the mating grounds (Gregory et al.
2011, p. 29). Johnsgard (2002, p. 129) stressed that the mating system
used by prairie grouse works most effectively when populations are
dense enough to provide the visual and acoustic stimuli necessary to
attract prebreeding females to the lek. Once established, the lek must
then be large enough to assure that the matings will be performed by
the most physically and genetically fit males. Lek breeding, where
relatively few males sire offspring, tends to promote inbreeding
(Bouzat and Johnson 2004, p. 503).
Therefore, as populations decline, several events begin to exert
influence on the viability of the affected population. As populations
decline, and the number of males attending a particular lek decline,
the probability that a lek will persistence also declines (Sandercock
et al. 2012, p. 11). Females may have difficulty locating leks as the
number of leks decline. Females also may not be attracted to an
existing lek as male lek attendance declines and the corresponding
collective visual and auditory display diminishes. Relatedly, as the
number of male birds attending a particular lek declines, females will
have fewer and fewer choices from which to select a mate, reducing the
likelihood that females will select the most fit male. Because male
lesser prairie-chickens have high site fidelity and consistently return
to a particular lek site (Copelin 1963, pp. 29-30; Hoffman 1963, p.
731; Campbell 1972, pp. 698-699), the same dominant, but perhaps less
fit, male may conduct the majority of the matings. As this continues
over several successive years, the potential for inbreeding becomes
more prevalent and the risk of impacts from harmful genetic effects
rises. Although an obvious oversimplification of the process, the
likelihood that lesser prairie-chickens will experience detrimental
genetic effects, such as inbreeding, is high and will only increase as
population sizes decline and become more fragmented over time. The
potential for possible genetic effects is amplified by the lek mating
system, where mating is performed by relatively few males (highly male
skewed) (Oyler-McCance et al. 2010, p. 121).
However, the tendency of female lesser prairie-chickens and other
prairie grouse to typically nest near a lek other than the one on which
they mated is an innate mechanism that can help enhance genetic mixing
and reduce the potential for of inbreeding to occur. Bouzat and Johnson
(2004, p. 504) believed that site fidelity in female lesser prairie-
chickens was lower than that for males and may help ensure low
relatedness in reproductive females at leks.
Johnson (2008, p. 171) reported that gene flow is currently
restricted between lesser prairie-chicken populations in New Mexico and
those in Oklahoma and expressed concern that genetic variability may
decline due to reduced population sizes. Hagen et al. (2010, p. 34)
also reported that the New Mexico population was significantly
different from populations in other States due to a lack of gene flow.
An isolated population of lesser prairie-chicken in New Mexico and
southwest Texas was reported to have lost genetic diversity due to
separation from the main population, and this separation may have
occurred since the 1800s (Corman 2011, p. 114).
These findings are not unexpected given information on lesser
prairie-chicken movements. Pruett et al. (2009b, p. 258) report
findings by the Sutton Center that lesser prairie-chickens in Oklahoma
were observed to move as much as 20 to 30 km (12 to 19 mi), but the
extant lesser prairie-chicken populations in New Mexico and Oklahoma
are separated by more than 200 km (124 mi). Given the limited movements
of individual lesser prairie-chickens and the distance between these
two populations, Pruett et al. (2009b, p. 258) considered interaction
between these populations to be highly unlikely. Johnson (2008, p. 171)
speculated that the observed estimate of gene flow between the New
Mexico and Oklahoma populations could be due to effects of recent
genetic drift as habitat fragmentation and isolation developed between
the New Mexico and Oklahoma populations. Corman (2011, p. 116) stated
that prolonged separation by an
[[Page 20060]]
isolated population in southwest Texas and eastern New Mexico may have
contributed to reduced variability in mitochondrial Deoxyribonucleic
acid (mtDNA, genetic material). Further examination of the viability of
existing lesser prairie-chicken populations will be needed to
thoroughly describe the effects of small population size and isolation
on persistence of the lesser prairie-chicken.
Dispersal is an important demographic factor that contributes to
genetically viable populations (Johnson 2003, p. 62). Fragmentation
that restricts dispersal capabilities can have dramatic impacts on the
level of genetic variability and thus evolutionary potential of
surviving populations (Johnson 2003, p. 62). Populations, such as the
lesser prairie-chicken, that have undergone large decreases in
population size are likely to lose genetic variation (Nei et al. 1975,
Maruyama and Fuerst 1985). Resistance to disease and ability of
populations to respond to environmental disturbances may also decrease
with the loss of genetic variation (Lacy 1997).
We have determined that genetic risks related to small population
size and the lek mating system, while not a significant concern at
current population levels, could begin to substantially impact lesser
prairie-chickens in the future, should populations continue to decline
or become more isolated by habitat fragmentation. The population in
Deaf Smith County, Texas is already showing signs of inbreeding due to
isolation (see discussion in section on Conservation Genetics).
Additionally, genetic examination of the northeast Texas population
revealed a dependence upon gene flow from Oklahoma and Kansas to
maintain adequate levels of genetic diversity. If this gene flow is
disrupted by habitat fragmentation, the northeast Texas population also
could be impacted by the effects of inbreeding. Considering Corman
(2011, pp. 49-50) observed that both the Deaf Smith and the Gray-Donley
County populations were intermediate between the New Mexico-southwest
Texas population and lesser prairie-chicken populations throughout the
remainder of the range, existing and anticipated genetic impacts to
these populations would further isolate the New Mexico-southwest Texas
population from the rest of the range. Further isolation could impact
the viability of the New Mexico-southwest Texas population. Continued
loss of genetic variation may negatively impact the long-term viability
of some lesser prairie-chicken populations.
Surface Water Impoundments
Dams have been constructed on streams within the range of the
lesser prairie-chicken to produce impoundments for flood control, water
supply, and other purposes. The impounded waters flood not only
affected stream segments and riparian areas, but also adjacent areas of
grassland and shrubland habitats that potentially provided usable space
for lesser prairie-chickens. Although lesser prairie-chickens may make
use of free-standing water, as is retained in surface impoundments, its
availability is not critical for survival of the birds (Giesen 1998, p.
4).
The historical range of the lesser prairie-chicken contains
approximately 25 large impoundments with a surface area greater than
1,618 ha (4,000 ac), the largest 20 of these (and their normal surface
acreage) are listed from largest to smallest in Table 5, below.
Table 5--Impoundments With Surface Acreage Greater Than 1,618 ha (4,000
ac) Within the Historical Range of the Lesser Prairie-Chicken
------------------------------------------------------------------------
Impoundment Surface acreage State
------------------------------------------------------------------------
John Martin Reservoir......... 8,302 ha (20,515 ac). Colorado.
O. H. Ivie Lake............... 7,749 ha (19,149 ac). Texas.
Lake Meredith................. 6,641 ha (16,411 ac). Texas.
Lake Kemp..................... 6,309 ha (15,590 ac). Texas.
Lake Arrowhead................ 6,057 ha (14,969 ac). Texas.
E. V. Spence Reservoir........ 6,050 ha (14,950 ac). Texas.
Hubbard Creek Reservoir....... 6,038 ha (14,922 ac). Texas.
Twin Buttes Reservoir......... 3,965 ha (9,800 ac).. Texas.
Cheney Reservoir.............. 3,859 ha (9,537 ac).. Kansas.
Wilson Lake................... 3,642 ha (9,000 ac).. Kansas.
Foss Lake..................... 3,561 ha (8,800 ac).. Oklahoma.
Great Salt Plains Lake........ 3,516 ha (8,690 ac).. Oklahoma.
Ute Reservoir................. 3,318 ha (8,200 ac).. New Mexico.
Canton Lake................... 3,201 ha (7,910 ac).. Oklahoma.
J. B. Thomas Reservoir........ 2,947 ha (7,282 ac).. Texas.
Cedar Bluff Reservoir......... 2,779 ha (6,869 ac).. Kansas.
Lake Brownwood................ 2,626 ha (6,490 ac).. Texas.
Tom Steed Lake................ 2,590 ha (6,400 ac).. Oklahoma.
Lake Altus-Lugert............. 2,533 ha (6,260 ac).. Oklahoma.
Lake Kickapoo................. 2,439 ha (6,028 ac).. Texas.
-----------------------
Total..................... 88,129 ha (217,772
ac).
------------------------------------------------------------------------
(Sources: Kansas Water Office 2012, New Mexico State Parks 2012, Texas
Parks and Wildlife Department 2012, Texas State Historical Association
2012, U.S. Army Corps of Engineers 2012, U.S. Bureau of Reclamation
2012.)
In addition, the historical range of the lesser prairie-chicken
contains many smaller impoundments, such as municipal reservoirs and
upstream flood control projects. For example, beginning in the mid-
1900s, the USDA constructed hundreds of small impoundments (floodwater
retarding structures) within the historical range of the lesser
prairie-chicken, through the Watershed Protection and Flood Prevention
Program. The program was implemented to its greatest extent in Oklahoma
(Oklahoma Conservation Commission 2005), and, within the portion of the
lesser prairie-chicken's historical range in that State, the USDA
constructed 574 floodwater retarding structures, totaling 6,070 ha
(15,001 ac) (Elsener 2012). Similarly, within the portion of the lesser
prairie-chicken's
[[Page 20061]]
historical range in Texas, the USDA constructed 276 floodwater
retarding structures, totaling 8,293 surface acres (Bednarz 2012). In
Kansas, considerably fewer floodwater retarding structures were
constructed within the historical range, totaling 857 ha (2,118 ac)
(Gross 2012). Even fewer such structures were constructed in Colorado
and New Mexico.
Cumulatively, the total area of historical lesser prairie-chicken
range lost due to construction of large, medium, and small impoundments
is about 98,413 ha (243,184 ac), or roughly 0.2 percent of the
historical range, and is much less than the amount of habitat lost or
degraded by other factors discussed in this rule (e.g., conversion of
rangeland to cropland and overgrazing). The Service expects a large
majority of existing reservoirs to be maintained over the long term.
Therefore, these structures will continue to displace former areas of
lesser prairie-chicken habitat, as well as fragment surrounding lands
as habitat for the lesser prairie-chicken, but the overall habitat loss
is relatively minor. Because extensive new dam construction is not
anticipated within the lesser prairie-chicken's range, the Service
considers it unlikely that reservoir construction will significantly
impact lesser prairie-chickens in the future.
In summary, several other natural or manmade factors are affecting
the continued existence of the lesser prairie-chicken. Parasitism of
lesser prairie-chicken nests by pheasants and hybridization with
greater prairie chickens have been documented but the incidence is low.
The impact is not significant at current levels. Hybridization is
occurring in a small portion of the estimated occupied range but the
immediate and long-term influence of hybridization on the species is
unknown. The incidence of hybridization is low, typically about 1
percent of the estimated total population. However, should the zone of
overlap between lesser and greater prairie-chickens expand,
hybridization could become a more significant stressor in the future.
As lesser prairie-chicken populations decline, number of potential
genetic factors associated with reduced population size may begin to
become more prevalent, particularly as populations become more
isolated. Although genetic risks related to small population size and
the lek mating system are not a significant concern at current
population levels, they could begin to substantially impact lesser
prairie-chickens in the future, Although past construction of surface
water impoundments within the historical range have eliminated
potential habitat, and continue to displace former areas of lesser
prairie-chicken habitat, including small areas within the estimated
occupied range, construction of large impoundments has slowed
considerably over the past several decades. Habitat losses from
reservoir construction are small, constituting roughly 0.2 percent of
the historical range. However, considering low population density can
increase the susceptibility of lesser prairie-chicken to possible
genetic effects and increase the negative effects of hybridization,
nest parasitism, and competition, we consider the effects of these
natural and manmade factors to be a threat to the lesser prairie-
chicken.
Adequacy of Existing Regulatory Mechanisms
Regulatory mechanisms, such as Federal, state, and local land use
regulations or laws, may provide protection from some threats provided
those regulations and laws are not discretionary and are enforceable.
In 1973, the lesser prairie-chicken was listed as a threatened
species in Colorado under the State's Nongame and Endangered or
Threatened Species Conservation Act. While this designation prohibits
unauthorized take, possession, and transport, that adequately protects
the species from direct purposeful mortality by humans, no protections
are provided for destruction or alteration of lesser prairie-chicken
habitat. In the remaining States, the lesser prairie-chicken is
classified as a game species, although the legal harvest is now closed
in New Mexico, Oklahoma, and Texas. Accordingly, the State conservation
agencies have the authority to regulate possession of the lesser
prairie-chicken, set hunting seasons, and issue citations for poaching.
For example, Texas Statute (Parks and Wildlife Code Section 64.003)
prohibits the destruction of nests or eggs of game birds such as the
lesser prairie-chicken. These authorities provide lesser prairie-
chickens with protection from direct mortality caused by hunting and
prohibit some forms of unauthorized take, and have been adequate to
address any concerns of overhunting, as evidenced by the fact that
these states have closed harvest in response to low population levels.
Alternatively, these authorities do not provide protection for
destruction or alteration of the species' habitat.
In July of 1997, the NMDGF received a formal request to commence an
investigation into the status of the lesser prairie-chicken within New
Mexico. This request began the process for potential listing of the
lesser prairie-chicken under New Mexico's Wildlife Conservation Act. In
1999, the recommendation to list the lesser prairie-chicken as a
threatened species under the Wildlife Conservation Act was withdrawn
until more information was collected from landowners, lessees, and land
resource managers who may be affected by the listing or who may have
information pertinent to the investigation. In late 2006, the New
Mexico State Game Commission determined that the lesser prairie-chicken
would not be State-listed in New Mexico. New Mexico's Wildlife
Conservation Act, under which the lesser prairie-chicken could have
been listed, offers little opportunity to prevent otherwise lawful
activities.
Regardless of each State's listing status, most occupied lesser
prairie-chicken habitat throughout its estimated occupied range occurs
on private land (Taylor and Guthery 1980b, p. 6), where State
conservation agencies have little authority to protect or direct
management of the species' habitat. All five States in the estimated
occupied range have incorporated the lesser prairie-chicken as a
species of conservation concern and management priority in their
respective State Wildlife Action Plans. While identification of the
lesser prairie-chicken as a species of conservation concern does help
heighten public awareness, this designation provides no protection from
direct take or habitat destruction or alteration.
Some States, such as Oklahoma, have laws and regulations that
address use of State school lands, primarily based on maximizing
financial return from operation of these lands. However, the scattered
nature of these lands and requirement to maximize financial returns
minimize the likelihood that these lands will be managed to reduce
degradation and fragmentation of habitat and ensure the conservation of
the species.
Lesser prairie-chickens are not covered or managed under the
provisions of the Migratory Bird Treaty Act (16 U.S.C. 703-712) because
they are considered resident game species. The lesser prairie-chicken
has an International Union for Conservation of Nature (IUCN) Red List
Category of ``vulnerable'' (BirdLife International 2008), and
NatureServe currently ranks the lesser prairie-chicken as G3--
Vulnerable (NatureServe 2011, entire). The lesser prairie-chicken also
is on the National Audubon Society's WatchList 2007 Red Category, which
is ``for species that are declining rapidly or have very small
populations or limited
[[Page 20062]]
ranges, and face major conservation threats.'' However, none of these
designations provide any regulatory protection.
There are six National Grasslands located within the estimated
historical range of the lesser prairie-chicken. Two of the six, the
Comanche National Grassland in Colorado and the Cimarron National
Grassland in Kansas, occur within the estimated occupied range. The
remaining four occur within or adjacent to counties that are occupied
with lesser prairie-chickens, but the National Grasslands themselves
are not within the delineation of the estimated occupied range. The
National Grasslands are managed by the USFS, have been under Federal
ownership since the late 1930s, and were officially designated as
National Grasslands in 1960. The Kiowa, Rita Blanca, Black Kettle, and
McClellan Creek National Grasslands are administered by the Cibola
National Forest. The Kiowa National Grassland covers 55,659 ha (137,537
ac) and is located within Mora, Harding, Union, and Colfax Counties,
New Mexico. The Rita Blanca National Grassland covers 37,631 ha (92,989
ac) and is located within Dallam County, Texas, and Cimarron County,
Oklahoma. The Black Kettle National Grassland covers 12,661 ha (31,286
ac) and is located within Roger Mills County, Oklahoma, and Hemphill
County, Texas. The McClellan Creek National Grassland covers 586 ha
(1,449 ac) and is located in Gray County, Texas. No breeding
populations of lesser prairie-chickens are known to occur on these
holdings.
The Comanche and Cimarron National Grasslands are under the
administration of the Pike and San Isabel National Forest. The Comanche
National Grassland covers 179,586 ha (443,765 ac) and is located within
Baca, Las Animas, and Otero Counties, Colorado. The Cimarron National
Grassland covers 43,777 ha (108,175 ac) and is located in Morton and
Stevens Counties, Kansas. Both of these areas are known to support
breeding lesser prairie-chickens. The National Forest Management Act of
1976 and the associated planning rule in effect at the time of planning
initiation are the principal law and regulation governing the planning
and management of National Forests and National Grasslands by the USFS.
Planning for the Kiowa, Rita Blanca, Black Kettle, and McClellan
Creek National Grasslands was well underway when the 2008 National
Forest System Land Management Planning Rule was enjoined on June 30,
2009, by the United States District Court for the Northern District of
California (Citizens for Better Forestry v. United States Department of
Agriculture, 632 F. Supp. 2d 968 (N.D. Cal. June 30, 2009)). A new
planning rule was finalized in 2012 (77 FR 67059) and became effective
on May 9, 2012. The transition provisions of the 2012 planning rule (36
CFR 219.17(b)(3)) allow those National Forest System lands that had
initiated plan development, plan amendments, or plan revisions prior to
May 9, 2012, to continue using the provisions of the prior planning
regulation. The Cibola National Forest and Grasslands used the guidance
of the 2012 Planning Rule transition language allowing the provisions
of the 1982 Planning Rule, including the requirement to prepare an
Environmental Impact Statement, to complete the new plan for these
National Grasslands. The management strategies for management of these
National Grasslands provide a strategic, outcome-oriented, programmatic
framework for future activities and will be implemented at the District
level through the application of certain Desired Conditions,
Objectives, Standards, and Guidelines. The Environmental Impact
Statement highlights that the new plan will allow for enhancement of
lesser prairie-chicken habitat by moving vegetation types toward the
species' desired vegetation structures and species composition, in
addition to reducing mortality caused by fence collision. As explained
above, the transition provisions (36 CFR 219.17(b)(3)) of the 2012
planning rule allow the use of the provisions of the 1982 planning
rule, including the requirement that management indicator species be
identified as part of the plan. Management indicator species serve
multiple functions in forest planning: Focusing management direction
developed in the alternatives, providing a means to analyze effects on
biological diversity, and serving as a reliable feedback mechanism
during plan implementation. The latter often is accomplished by
monitoring population trends in relationship to habitat changes.
Although suitable habitat is present, no breeding populations of lesser
prairie-chickens are known from the Kiowa, Rita Blanca, Black Kettle,
and McClellan Creek National Grasslands. Consequently, the lesser
prairie-chicken is not designated as a management indicator species in
the plan. Instead the lesser prairie-chicken is included on the
Regional Forester's sensitive species list and as an At-Risk species.
In 2008, a new National Forest System Land Management Planning Rule
(36 CFR Part 219) took effect and was used to guide the development of
a Land and Resource Management Plan for the Comanche and Cimarron
National Grasslands. That plan was one of the first plans developed and
released under the 2008 planning rule. The predecisional review version
of the Cimarron and Comanche National Grasslands Land Management Plan
was made available to the public on October 17, 2008. The lesser
prairie-chicken was included as a species-of-concern in accordance with
guidance available in the existing planning rule (USFS 2008, p. 35). As
defined in the 2008 planning rule, species-of-concern are species for
which the Responsible Official determines that management actions may
be necessary to prevent listing under the Endangered Species Act (36
CFR 219.16). Identification of the lesser prairie-chicken as a species-
of-concern in the Cimarron and Comanche National Grasslands Land
Management Plan led to inclusion of planning objectives targeting
improvement of the species' habitat, as described below.
The Comanche and Cimarron National Grasslands currently manage the
Comanche Lesser Prairie-chicken Habitat Zoological Area, now designated
as a Colorado Natural Area, which encompasses an area of 4,118 ha
(10,177 ac) that is managed to benefit the lesser prairie-chicken.
Current conditions on this area include existing oil and gas leases,
two-track roads, utility corridors, and livestock grazing. Wildfires on
the area have been suppressed over the last 30 years. The area provides
a special viewing area for the lesser prairie-chicken, which has been
closed to protect lekking activities. The 1984 plan specifies that the
condition of the area should meet the special habitat needs of the
lesser prairie-chicken, specifically protection of leks from all
surface disturbance, protection of nesting habitat from surface
disturbance during the nesting period (April 15 to June 30) and
limiting forage use by livestock and wild herbivores to no more than 40
percent.
The USFS contracted with lesser prairie-chicken experts to prepare
the lesser prairie-chicken technical conservation assessment, which is
a succinct evaluation of species of potential viability concern, (Robb
and Schroeder 2005, entire). The conservation assessment addresses the
biology, ecology, conservation, and management of the species
throughout its range, but it primarily focuses on Colorado and Kansas
(Forest Service Region 2) (Robb and Schroeder 2005, p.
[[Page 20063]]
7). Species conservation assessments produced as part of the Species
Conservation Project are designed to provide land managers, biologists,
and the public with a thorough discussion of the biology, ecology,
conservation, and management of the lesser prairie-chicken based on
existing scientific knowledge and to provide the ecological background
upon which management should be based, focusing on the consequences of
changes in the environment that result from management (Robb and
Schroeder 2005, p. 7). This conservation assessment for the lesser
prairie-chicken was completed in 2005 and affirmed the need for the
USFS to retain sensitive species status designation for the lesser
prairie-chicken. The criteria evaluated for inclusion on the sensitive
species list include distribution, dispersal capability, abundance,
population trend, habitat trend, habitat vulnerability or modification,
and life history and demographics. The sensitive species recommendation
form for the lesser prairie-chicken states that the species clearly
warrants sensitive species designation because habitat loss,
fragmentation and degradation are still significant risk factors on
both USFS and surrounding private lands. Management activities on the
National Grasslands throughout the range of the lesser prairie-chicken
may be guided by the technical conservation assessment; however, the
document only provides summaries of existing scientific knowledge,
discussion of broad implications of that knowledge, and outlines of
information needs. The technical conservation assessment does not seek
to develop specific prescriptions for management of populations and
habitats. Instead, it is intended to provide the ecological background
upon which management should be based and focuses on the consequences
of changes in the environment that result from management (i.e.,
management implications). This document can be found at http://www.fs.fed.us/r2/projects/scp/assessments/lesserprairiechicken.pdf.
The other primary Federal surface ownership of lands occupied by
the lesser prairie-chicken is administered by the BLM in New Mexico. In
New Mexico, roughly 41 percent of the known historical and most of the
estimated occupied lesser prairie-chicken range occurs on BLM land. The
BLM currently manages approximately 342,969 surface ha (847,491 ac)
within lesser prairie-chicken range in eastern New Mexico. They also
oversee another 120,529 ha (297,832 ac) of Federal minerals below
private surface ownership. The core of currently occupied lesser
prairie-chicken habitat in New Mexico is within the Roswell BLM
Resource Area. However, the Carlsbad BLM Resource Area comprised much
of the historical southern periphery of the species' range in New
Mexico.
The BLM established the 23,278-ha (57,522-ac) Lesser Prairie-
Chicken Habitat Preservation Area of Critical Environmental Concern
(ACEC) upon completion of the RMPA in 2008; the purpose of the ACEC is
to maintain and enhance habitat for the lesser prairie-chicken and the
dunes sagebrush lizard (Sceloporus arenicolus) (BLM 2008, p. 1). The
management goal for the ACEC is to protect the biological qualities of
the area, with emphasis on the preservation of the shinnery oak-dune
community to enhance the biodiversity of the ecosystem, particularly
habitats for the lesser prairie-chicken and the dunes sagebrush lizard.
The ACEC not only includes 20,943 ha (51,751 ac) public land surface
acres, in addition to State trust land and private land, but also
includes 18,981 ha (46,902 ac) of Federal mineral estate (BLM 2008, p.
30). Upon designation, the ACEC was closed to future oil and gas
leasing, and existing leases would be developed in accordance with
prescriptions applicable to the Core Management Area as described below
(BLM 2008, p. 30). Additional management prescriptions for the ACEC
include designation as a right-of-way exclusion area, vegetation
management to meet the stated management goal of the area, and limiting
the area to existing roads and trails for off-highway vehicle use (BLM
2008, p. 31). All acres of the ACEC have been closed to grazing through
relinquishment of the permits except for one 1393 ha (3,442 ac)
allotment.
The BLM's amended RMPA (BLM 2008, pp. 5-31) provides some limited
protections for the lesser prairie-chicken in New Mexico by reducing
the number of drilling locations, decreasing the size of well pads,
reducing the number and length of roads, reducing the number of
powerlines and pipelines, and implementing best management practices
for development and reclamation. Implementation of these protective
measures, particularly curtailment of new mineral leases, would be
greatest in the Core Management Area and the Primary Population Area
habitat management units (BLM 2008, pp. 9-11). The Core Management and
Primary Population Areas are located in the core of the lesser prairie-
chicken estimated occupied range in New Mexico. The effect of these
best management practices on the status of the lesser prairie-chicken
is unknown, particularly considering about 33,184 ha (82,000 ac) have
already been leased in those areas (BLM 2008, p. 8). The effectiveness
of the amended RMPA is hampered by a lack of explicit measures designed
to improve the status of the lesser prairie-chicken, limited certainty
that resources will be available to carry out the management plan,
limited regulatory or procedural mechanisms in place to carry out the
efforts, lack of monitoring efforts, and provision for exceptions to
the best management practices under certain conditions, which could
negate the benefit of the conservation measures.
The amended RMPA stipulates that implementation of measures
designed to protect the lesser prairie-chicken and dunes sagebrush
lizard may not allow approval of all spacing unit locations or full
development of a lease (BLM 2008, p. 8). In addition, the RMPA
prohibits drilling and exploration in lesser prairie-chicken habitat
between March 1 and June 15 of each year (BLM 2008, p. 8). No new
mineral leases will be issued on approximately 32 percent of Federal
mineral acreage within the RMPA planning area (BLM 2008, p. 8),
although some exceptions are allowed on a case-by-case basis (BLM 2008,
pp. 9-11). Within the Core Management Area and Primary Population Area,
new leases will be restricted in occupied and suitable habitat;
however, if there is an overall increase in reclaimed to disturbed
acres over a 5-year period, new leases in these areas will be allowed
(BLM 2008, p. 11). Considering Hunt and Best (2004, p. 92) concluded
that petroleum development at intensive levels likely is not compatible
with populations of lesser prairie-chicken, additional development in
the Core Management Area and Primary Population Area habitat management
units may hinder long-term conservation of the species in New Mexico.
The RMPA allows lease applicants to voluntarily participate in a power
line removal credit to encourage removal of idle power lines (BLM 2008,
pp. 2-41). In the southernmost habitat management units, the Sparse and
Scattered Population Area and the Isolated Population Area, where
lesser prairie-chickens are now far less common than in previous
decades (Hunt and Best 2004), new leases will not be allowed within 2.4
km (1.5 mi) of a lek (BLM 2008, p. 11).
The overall ineffectiveness of certain imposed energy development
stipulations near leks for the purpose of
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protecting grouse on Federal lands has been confirmed for sage grouse.
Holloran (2005, p. 57) and Naugle et al. (2006a, p. 3) documented that
sage grouse avoid energy development (coalbed methane) not only in
breeding and nesting habitats, but also in wintering habitats. They
assert that current best management practices in use by Federal land
management agencies that place timing stipulations or limit surface
occupancy near greater sage-grouse leks result in a human footprint
that far exceeds the tolerance limits of sage grouse. Ultimately, they
recommended that effective conservation strategies for grouse must
limit the cumulative impact of habitat disturbance, modification, and
destruction in all habitats and at all times of the year (Holloran
2005, p. 58; Naugle et al. 2006b, p. 12). Additional research on the
effect of petroleum development on lesser prairie-chicken is needed.
However, available information on the lesser prairie-chicken (Suminski
1977, p. 70; Hagen et al. 2004, pp. 74-75; Hunt and Best 2004, p. 92;
Pitman et al. 2005, pp. 1267-1268) indicates that the effect of
petroleum development is often detrimental, particularly during the
breeding season.
Because only about 4 percent of the species' overall range occurs
on Federal lands, the Service recognizes that the lesser prairie-
chicken cannot be fully recovered on Federal lands alone. However, no
laws or regulations currently protect lesser prairie-chicken habitat on
private land, aside from State harvest restrictions. Therefore, the
Service views decisions regarding the management and leasing of Federal
lands and minerals within existing lesser prairie-chicken range as
important to the future conservation and persistence of the species.
Since 2004, the construction of commercial wind energy projects
near and within estimated occupied lesser prairie-chicken habitat has
raised concerns about the potential negative effects such projects may
have on the species, if constructed at large scales in occupied range.
As discussed previously, a rapid expansion of transmission lines and
associated wind energy development throughout large portions of
occupied lesser prairie-chicken range is occurring. Because most wind
development activities are privately funded and are occurring on
private land, wind energy siting, development, and operation falls
outside the purview of the National Environmental Policy Act of 1969
(NEPA) and, within the range of the lesser prairie-chicken, other
Federal conservation statues and regulatory processes. As a result,
Federal law and policy does not generally regulate the wind development
activities in regard to the lesser prairie-chicken.
The current lack of regulatory oversight and public notice
requirements for the construction of wind generation and related
transmission facilities is a concern. Specifically, the Service is
unaware of any state or Federal mechanisms that require potential wind
energy producers to disclose the location, size, and anticipated
construction date for pending projects on non-Federal lands or require
analysis under the provisions of the NEPA. Lacking the ability to
obtain pertinent siting information or analyze alternative siting
locations, neither the Service nor State conservation agencies
currently have the ability to accurately influence the size or timing
of wind generation construction activities within occupied lesser
prairie-chicken habitat.
In summary, most occupied lesser prairie-chicken habitat occurs on
private land, where State conservation agencies currently have little
authority to protect lesser prairie-chicken or facilitate and monitor
management of lesser prairie-chicken habitat beyond regulating
recreational harvest. Because most lesser prairie-chicken habitat
destruction and modification on private land occurs through otherwise
lawful activities such as agricultural conversion, livestock grazing,
energy development, and fire exclusion, few (if any) regulatory
mechanisms are in place to substantially alter human land uses at a
sufficient scale to protect lesser prairie-chicken populations and
their habitat. While almost no regulatory protection is in place for
the species, regulatory incentives, in the form of county, state, and
national legislative actions, have been created to facilitate the
expansion of activities that result in fragmentation of occupied lesser
prairie-chicken habitat, such as that resulting from oil, gas, and wind
energy development. For the remaining 4 percent of occupied habitat
currently under Federal management, habitat quality depends primarily
on factors related to multiple use mandates, such as livestock grazing
and oil, gas, and wind power development activities. Because prior
leasing commitments and management decisions on the majority of
occupied parcels of Federal land offer little flexibility for reversal,
any new regulatory protection for uncommitted land units are important
and will take time to achieve substantial benefits for the species in
the long term.
We note that the existing regulatory mechanisms at the Federal and
State level have not been sufficient to halt the decline of the
species. Further, the best available information does not show any
existing regulatory mechanisms at the local level that address the
identified threats to the species. In spite of the existing regulatory
mechanisms, the current and projected threat from the loss and
fragmentation of lesser prairie-chicken habitat and range is still
ongoing. The existing regulatory mechanisms have not been effective at
removing all of the impacts to lesser prairie-chickens and their
habitat.
Determination
Section 4 of the Act (16 U.S.C. 1533), and its implementing
regulations at 50 CFR part 424, set forth the procedures for adding
species to the Federal Lists of Endangered and Threatened Wildlife and
Plants. Under section 4(a)(1) of the Act, we may list a species based
on (A) The present or threatened destruction, modification, or
curtailment of its habitat or range; (B) overutilization for
commercial, recreational, scientific, or educational purposes; (C)
disease or predation; (D) the inadequacy of existing regulatory
mechanisms; or (E) other natural or manmade factors affecting its
continued existence. Listing actions may be warranted based on any of
the above threat factors, singly or in combination.
As required by the Act, we considered the five factors in assessing
whether the lesser prairie-chicken meets the definition of an
endangered or a threatened species. We examined the best scientific and
commercial information available regarding the past, present, and
future threats faced by the lesser prairie-chicken. Based on our review
of the best available scientific and commercial information, we find
the lesser prairie-chicken is likely to become in danger of extinction
in the foreseeable future and, therefore, meets the definition of a
threatened species.
The life history and ecology of the lesser prairie-chicken make it
exceptionally vulnerable to changes on the landscape, especially at its
currently reduced numbers. As discussed above, this vulnerability to
habitat impacts results from the species' lek breeding system, which
requires males and females to be able to hear and see each other over
relatively wide distances; the need for large patches of habitat that
include several types of microhabitats; and the behavioral avoidance of
vertical structures. Specifically, the lesser prairie-chicken's
behavioral avoidance of vertical structures causes its habitat to be
more functionally fragmented than another species' habitat would be.
For example, a snake likely would continue
[[Page 20065]]
to use habitat underneath a wind turbine, but the lesser prairie-
chicken's predator avoidance behavior causes it to avoid a large area
(estimated to be 1 mile) around a tall vertical object. The habitat
within that 1.6-km (1-mi) buffer continues to be otherwise suitable for
lesser prairie-chickens, but the entire area is avoided because of the
vertical structure. As a result, the impact of any individual
fragmenting feature is of higher magnitude than the physical footprint
of that structure would suggest it should be.
The ongoing and future impacts of cumulative habitat loss and
fragmentation to the lesser prairie-chicken are widespread and of high
magnitude. Most importantly, the probable future negative impacts to
the species and its habitat are the result of conversion of grasslands
to agricultural uses; encroachment by invasive, woody plants; wind
energy development; petroleum production; roads; and presence of
manmade vertical structures, including towers, utility lines, fences,
turbines, wells, and buildings. The historical and current impact of
these fragmenting factors has reduced the status of the species to the
point that individual populations are vulnerable to extirpation as a
result of stochastic events such as extreme weather events.
Additionally, these populations are more vulnerable to the effects of
climate change, disease, and predation than they would have been at
historical population levels. These threats are currently impacting
lesser prairie-chickens throughout their range and, as detailed
individually above, are projected to increase in severity into the
foreseeable future.
The range of the lesser prairie-chicken has been reduced by an
estimated 84 percent since pre-European settlement. The vulnerability
of lesser prairie-chickens to changes on the landscape is magnified
compared to historical times due to the species' reduced population
numbers, prevalence of isolated populations, and reduced range. There
are few areas of large patches of unfragmented, suitable grassland
remaining. Based on our analysis presented earlier, approximately 98.96
percent of the remaining suitable habitat patches were less than 486 ha
(1,200 ac) in size. In addition, 99.97 percent of the remaining
suitable habitat patches were less than 6,475 ha (16,000 ac) in size.
In order to thrive and colonize unoccupied areas, lesser prairie-
chickens require large patches of functionally unfragmented habitat
that include a variety of microhabitats needed to support lekking,
nesting, brood rearing, feeding for young, and feeding for adults,
among other things. Habitat patches that do not contain all of these
microhabitats may support population persistence but may not support
thriving populations that can produce surplus males capable of
colonizing new areas or recolonizing previously extirpated areas.
The species has a reduced population size and faces ongoing habitat
loss and degradation. The species will lack sufficient redundancy and
resiliency to ensure its viability from present and future threats. As
a result, the status of the species has been reduced to the point that
individual populations are vulnerable to extirpation due to a variety
of stochastic events (e.g., drought, winter storms). These extirpations
are especially significant because, in many places, there are no
nearby, connected populations with robust numbers that can rescue the
extirpated populations (i.e., be a source for recolonization).
Stochastic events will not affect all populations equally such all of
the remaining populations are not likely to be extirpated at once;
however, without intervention, population numbers will continue to
decline and the range of the species will continue to contract.
There are numerous ongoing conservation efforts throughout the
range of the species that are working to reduce or remove many of the
threats affecting the lesser prairie-chicken. However, those existing
efforts are largely focused on just one or two of the threats that the
lesser prairie-chicken is facing, and, in total, those efforts largely
do not address two of the more significant threats to the lesser
prairie-chicken into the future, namely oil and gas development and
wind energy development. Additionally, despite those ongoing efforts,
the status of the species has continued to decline, presumably as a
result of the effects of drought. The WAFWA recently finalized their
rangewide plan, a landmark conservation effort that is intended to
address, in part, those threat sources that are not covered elsewhere.
While we have determined that the rangewide plan will provide a net
conservation benefit to the species, the positive benefits of that
effort are expected to occur in the future rather than now at the time
of listing.
In summary, because of the reduction in the numbers and range of
lesser prairie-chickens resulting from cumulative ongoing habitat
fragmentation, combined with the lack of sufficient redundancy and
resiliency of current populations, we conclude that the lesser prairie-
chicken is currently at risk of extinction or is likely to be in danger
of extinction in the foreseeable future.
We must then assess whether the species is in danger of extinction
now (i.e., an endangered species) or is likely to become in danger of
extinction in the foreseeable future (i.e., a threatened species). In
assessing the status of the lesser prairie-chicken, we applied the
general understanding of ``in danger of extinction'' as discussed in
the December 22, 2010, memo to the polar bear listing determination
file, ``Supplemental Explanation for the Legal Basis of the
Department's May 15, 2008, Determination of Threatened Status for the
Polar Bear,'' signed by then Acting Director Dan Ashe (hereafter
referred to as Polar Bear Memo). As discussed in the Polar Bear Memo, a
key statutory difference between an endangered species and a threatened
species is the timing of when a species may be in danger of extinction
(i.e., currently on the brink of extinction), either now (endangered
species) or in the foreseeable future (threatened species).
As discussed in the Polar Bear Memo, because of the fact-specific
nature of listing determinations, there is no single metric for
determining if a species is ``in danger of extinction'' now.
Nonetheless, the practice of the Service over the past four decades has
been consistent. Species that the Service has determined to be in
danger of extinction now, and therefore appropriately listed as an
endangered species, generally fall into four basic categories:
(1) Species facing a catastrophic threat from which the risk of
extinction is imminent and certain.
(2) Narrowly restricted endemics that, as a result of their limited
range or population size are vulnerable to extinction from elevated
threats.
(3) Species formally more widespread that have been reduced to such
critically low numbers or restricted ranges that they are at a high
risk of extinction due to threats that would not otherwise imperil the
species.
(4) Species with still relatively widespread distribution that have
nevertheless suffered ongoing major reductions in their numbers, range,
or both, as a result of factors that have not been abated.
The best scientific and commercial data available indicate that the
lesser prairie-chicken could fit into the fourth category. However, as
noted in the Polar Bear Memo, threatened species share some
characteristics with this category of endangered species where the
recent decline in population, range, or both, is to a less severe
extent. The Polar Bear Memo indicates that ``[w]hether a
[[Page 20066]]
species in this situation is ultimately an endangered species or
threatened species depends on the specific life history and ecology of
the species, the natures of the threats, and population numbers and
trends.'' The Polar Bear Memo provides examples of species that
suffered fairly substantial declines in numbers or range and were
appropriately listed as threatened because the species as a whole was
not in danger of extinction, although the Service could foresee the
species reaching the brink of extinction.
As discussed above, the foreseeable future refers to the extent to
which the Secretary can reasonably rely on predictions about the future
in making determinations about the future conservation status of the
species. For the lesser prairie-chicken, information about the primary
ongoing and future threats is reasonably well-known and reliable. Thus,
we used the best scientific and commercial data available to analyze
and identify the primary ongoing and future threats to the lesser
prairie-chicken. As discussed in the Polar Bear Memo, species like the
lesser prairie-chicken that have suffered ongoing, major reductions in
numbers or range (or both) due to factors that have not been abated may
be classified as threatened species if some populations appear stable,
which would indicate that the entity as a whole was not in danger of
extinction now (i.e., not an endangered species). In the case of the
lesser prairie-chicken, the best available information indicates that,
while there have been major range reductions (84 percent) as a result
of factors that have not been abated (cumulative habitat fragmentation
and drought), there are sufficient stable populations such that the
species is not on the brink of extinction. Specifically, in the Short-
Grass/CRP mosaic ecoregion of northwestern Kansas, the lesser prairie-
chicken has reoccupied parts of its former range after landowners
enrolled in CRP, creating large blocks of high-quality habitat
beneficial to the species. This population is considered relatively
secure in the near term, as it is primarily comprised of CRP lands that
are in 10- to 15-year contracts. Further, lesser prairie-chicken
populations are spread over a large geographical area, and the current
range of the species includes populations that represent the known
diversity of ecological settings for the lesser prairie-chicken. As a
result, it is unlikely that a single stochastic event (e.g., drought,
winter storm) will affect all known extant populations equally or
simultaneously; therefore, it would require several stochastic events
over a number of years to bring the lesser prairie-chicken to the brink
of extinction due to those factors alone. In addition, the current and
ongoing threats of conversion of grasslands to agricultural uses;
encroachment by invasive, woody plants; wind energy development; and
petroleum production are not likely to impact all remaining populations
significantly in the near term because these activities either move
slowly across the landscape or take several years to plan and
implement. These threats are also less likely to significantly impact
the Kansas lesser prairie-chicken population in the near term because
of its relative security (e.g., land use is unlikely to change through
the term of the CRP contracts), as described above. Therefore, there
are sufficient populations to allow the lesser prairie-chicken to
persist into the near future, it is not in danger of extinction
throughout all of its range now. However, because of the nature of the
ongoing threats to the species, the Service can foresee the species
reaching the brink of extinction, and the species, therefore,
appropriately meets the definition of a threatened species (i.e.,
likely to become in danger of extinction in the foreseeable future).
In conclusion, as described above, the lesser prairie-chicken has
experienced significant reductions in range and population numbers, is
especially vulnerable to impacts due to its life history and ecology,
and is subject to significant current and future threats. We conclude
that there are sufficient populations to allow the species to persist
into the near future. Therefore, after a review of the best available
scientific information as it relates to the status of the species and
the five listing factors, we find the lesser prairie-chicken is likely
to become in danger of extinction in the foreseeable future throughout
its range. Therefore, we are listing the lesser prairie-chicken as a
threatened species.
Available Conservation Measures
Conservation measures provided to species listed as endangered or
threatened under the Act include recognition, recovery actions,
requirements for Federal protection, and prohibitions against certain
practices. Recognition through listing often results in public
awareness and facilitates conservation by Federal, State, Tribal, and
local agencies; private organizations; and individuals. The Act
encourages cooperation with the States and requires that recovery
actions be carried out for all listed species. The protection required
by Federal agencies and the prohibitions against certain activities
involving listed species are discussed, in part, below.
Recovery Planning
The primary purpose of the Act is the conservation of endangered
and threatened species and the ecosystems upon which they depend. The
ultimate goal of such conservation efforts is the recovery of these
listed species, so that they no longer need the protective measures of
the Act. Subsection 4(f) of the Act requires the Service to develop and
implement recovery plans for the conservation of endangered and
threatened species. The recovery planning process involves the
identification of actions that are necessary to halt or reverse the
species' decline by addressing the threats to its survival and
recovery. The goal of this process is to restore listed species to a
point where they are secure, self-sustaining, and functioning
components of their ecosystems.
Recovery planning includes the development of a recovery outline
soon after a species is listed, preparation of a draft and final
recovery plan, and periodic revisions to the plan as significant new
information becomes available. The recovery outline guides the
immediate implementation of urgently needed recovery actions and
describes the process to be used to develop a recovery plan. The
recovery plan identifies site-specific management actions that, when
implemented, will achieve recovery of the species, measurable criteria
that determine when a species may be downlisted or delisted, and
methods for monitoring recovery progress. Recovery plans also establish
a framework for agencies to coordinate their recovery efforts and
provide estimates of the cost of implementing recovery tasks. Recovery
teams (comprised of species experts, Federal and State agencies,
nongovernment organizations, and stakeholders) are often established to
develop recovery plans. When completed, the recovery outline, draft
recovery plan, and the final recovery plan will be available on our Web
site (http://www.fws.gov/endangered), or from our Oklahoma Ecological
Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Implementation of recovery actions generally requires the
participation of a broad range of partners, including other Federal
agencies, States, Tribal and nongovernmental organizations, businesses,
and private landowners. Examples of recovery actions include habitat
restoration (e.g., restoration of native vegetation), research and
monitoring, captive propagation and
[[Page 20067]]
reintroduction, and outreach and education. Although land acquisition
is an example of a type of recovery action, the recovery of many listed
species cannot be accomplished solely on Federal lands because their
range may occur primarily or solely on non-federal lands. Consequently,
recovery of these species will require cooperative conservation efforts
involving private, State, and possibly Tribal lands.
Once this species is listed, funding for recovery actions will be
available from a variety of sources, including Federal budgets, State
programs, and cost share grants for non-federal landowners, the
academic community, and nongovernmental organizations. In addition,
under section 6 of the Act, the States of Colorado, Kansas, New Mexico,
Oklahoma, and Texas will be eligible for Federal funds to implement
management actions that promote the protection and recovery of the
lesser prairie-chicken. Information on our grant programs that are
available to aid species recovery can be found at: http://www.fws.gov/grants.
Please let us know if you are interested in participating in
recovery efforts for the lesser prairie-chicken. Additionally, we
invite you to submit any new information on this species whenever it
becomes available and any information you may have for recovery
planning purposes (see FOR FURTHER INFORMATION CONTACT).
Federal Agency Consultation
Section 7(a) of the Act, as amended, requires Federal agencies to
evaluate their actions with respect to any species that is proposed or
listed as endangered or threatened and with respect to its critical
habitat, if any is designated. Regulations implementing this
interagency cooperation provision of the Act are codified at 50 CFR
part 402. Section 7(a)(4) requires Federal agencies to confer with the
Service on any action that is likely to jeopardize the continued
existence of a species proposed for listing or result in destruction or
adverse modification of proposed critical habitat. If a species is
listed subsequently, section 7(a)(2) of the Act requires Federal
agencies to ensure that activities they authorize, fund, or carry out
are not likely to jeopardize the continued existence of the species or
destroy or adversely modify its critical habitat. If a Federal action
may adversely affect a listed species or its critical habitat, the
responsible Federal agency must enter into formal consultation with the
Service.
Some examples of Federal agency actions within the species' habitat
that may require conference or consultation, or both, as described in
the preceding paragraph include landscape-altering activities on
Federal lands; provision of Federal funds to State and private entities
through Service programs, such as the PFW Program, State Wildlife Grant
Program, and Federal Aid in Wildlife Restoration program; construction
and operation of communication, radio, and similar towers by the
Federal Communications Commission or Federal Aviation Administration;
issuance of section 404 Clean Water Act permits by the U.S. Army Corps
of Engineers; construction and management of petroleum pipeline and
power line rights-of-way by the Federal Energy Regulatory Commission;
construction and maintenance of roads or highways by the Federal
Highway Administration; implementation of certain USDA agricultural
assistance programs; Federal grant, loan, and insurance programs;
Federal habitat restoration programs such as EQIP; and development of
Federal minerals, such as oil and gas.
Prohibitions and Exceptions
The purposes of the Act are to provide a means whereby the
ecosystems upon which endangered species and threatened species depend
may be conserved, to provide a program for the conservation of such
endangered species and threatened species, and to take such steps as
may be appropriate to achieve the purposes of the treaties and
conventions set forth in the Act. The Act is implemented through
regulations found in the Code of Federal Regulations (CFR). When a
species is listed as endangered, certain actions are prohibited under
section 9 of the Act, as specified in 50 CFR 17.21. These prohibitions,
which will be discussed further below, include, among others, take
within the United States, within the territorial seas of the United
States, or upon the high seas; import; export; and shipment in
interstate or foreign commerce in the course of a commercial activity.
The Act does not specify particular prohibitions, or exceptions to
those prohibitions, for threatened species. Instead, under section 4(d)
of the Act, the Secretary of the Interior was given the discretion to
issue such regulations as he deems necessary and advisable to provide
for the conservation of such species. The Secretary also has the
discretion to prohibit by regulation with respect to any threatened
species, any act prohibited under section 9(a)(1) of the Act.
Exercising this discretion, the Service has developed general
prohibitions (50 CFR 17.31) and exceptions to those prohibitions (50
CFR 17.32) under the Act that apply to most threatened species. Under
50 CFR 17.32, permits may be issued to allow persons to engage in
otherwise prohibited acts. Alternately, for threatened species, the
Service may develop specific prohibitions and exceptions that are
tailored to the specific conservation needs of the species. In such
cases, some of the prohibitions and authorizations under 50 CFR 17.31
and 17.32 may be appropriate for the species and incorporated into a
special rule under section 4(d) of the Act, but the 4(d) special rule
will also include provisions that are tailored to the specific
conservation needs of the threatened species and which may be more or
less restrictive than the general provisions at 50 CFR 17.31. Elsewhere
in today's Federal Register, we published a final 4(d) special rule
that provides measures that are necessary and advisable to provide for
the conservation of the lesser prairie-chicken.
We may issue permits to carry out otherwise prohibited activities
involving endangered and threatened wildlife species under certain
circumstances. Regulations governing permits are codified at 50 CFR
17.32 for threatened species. A permit must be issued for the following
purposes: For scientific purposes, to enhance the propagation or
survival of the species, and for incidental take in connection with
otherwise lawful activities. We anticipate that we would receive
requests for all three types of permits, particularly as they relate to
development of wind power facilities or implementation of safe harbor
agreements. Requests for copies of the regulations regarding listed
species and inquiries about prohibitions and permits may be addressed
to the Field Supervisor at the address in the FOR FURTHER INFORMATION
CONTACT section.
It is our policy, as published in the Federal Register on July 1,
1994 (59 FR 34272), to identify to the maximum extent practicable at
the time a species is listed, those activities that would or would not
constitute a violation of section 9 of the Act. The intent of this
policy is to increase public awareness of the effect of a proposed
listing on proposed and ongoing activities within the range of the
newly listed species. The following activities could potentially result
in a violation of section 9 of the Act; this list is not comprehensive:
(1) Unauthorized collecting, handling, possessing, selling,
delivering, carrying, or transporting of the species, including import
or export across State lines and international boundaries, except for
[[Page 20068]]
properly documented antique specimens of these taxa at least 100 years
old, as defined by section 10(h)(1) of the Act.
(2) Actions that would result in the unauthorized destruction or
alteration of the species' occupied habitat, as described in this rule.
Such activities could include, but are not limited to, the removal of
native shrub or herbaceous vegetation by any means for any
infrastructure construction project or direct conversion of native
shrub or herbaceous vegetation to another land use.
(3) Actions that would result in the long-term (e.g., greater than
3 years) alteration of preferred vegetative characteristics of lesser
prairie-chicken habitat, as described in this rule, particularly those
actions that would cause a reduction or loss in the native invertebrate
community within those habitats. Such activities could include, but are
not limited to, inappropriate livestock grazing, the application of
herbicides or insecticides, and seeding of nonnative plant species that
would compete with native vegetation for water, nutrients, and space.
(4) Actions that would result in lesser prairie-chicken avoidance
of an area during one or more seasonal periods. Such activities could
include, but are not limited to, the construction of vertical
structures such as power lines, fences, communication towers, and
buildings; motorized and nonmotorized recreational use; and activities
such as well drilling, operation, and maintenance, which would entail
significant human presence, noise, and infrastructure.
(5) Actions, intentional or otherwise, that would result in the
destruction of eggs or active nests or cause mortality or injury to
chicks, juveniles, or adult lesser prairie-chickens.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the Oklahoma
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).
Critical Habitat Designation for Lesser Prairie-Chicken
Background
Critical habitat is defined in section 3 of the Act as:
(i) The specific areas within the geographical area occupied by the
species, at the time it is listed in accordance with the Act, on which
are found those physical or biological features:
(I) Essential to the conservation of the species, and
(II) Which may require special management considerations or
protection; and
(ii) Specific areas outside the geographical area occupied by the
species at the time it is listed, upon a determination that such areas
are essential for the conservation of the species.
Conservation, as defined under section 3 of the Act, means using
all methods and procedures deemed necessary to bring an endangered or
threatened species to the point at which the measures provided pursuant
to the Act are no longer necessary. Such methods and procedures
include, but are not limited to, all activities associated with
scientific resources management such as research, census, law
enforcement, habitat acquisition and maintenance, propagation, live
trapping, and transplantation, and, in the extraordinary case where
population pressures within a given ecosystem cannot be relieved
otherwise, may include regulated taking.
Critical habitat receives protection under section 7(a)(2) of the
Act through the requirement that Federal agencies insure, in
consultation with the Service, that any action they authorize, fund, or
carry out is not likely to result in the destruction or adverse
modification of critical habitat. The designation of critical habitat
does not alter land ownership or establish a refuge, wilderness,
reserve, preserve, or other conservation area. Such designation does
not allow the government or public to access private lands. Such
designation does not require implementation of restoration, recovery,
or enhancement measures by non-Federal landowners. Instead, where a
landowner seeks or requests Federal agency funding or authorization for
an action that may affect a listed species or critical habitat, the
consultation requirements of section 7(a)(2) would apply, but even in
the event of a destruction or adverse modification finding, the
obligation of the Federal action agency and the applicant is not to
restore or recover the species, but to implement reasonable and prudent
alternatives to avoid destruction or adverse modification of critical
habitat.
Under the first prong of the Act's definition of critical habitat,
areas within the geographical area occupied by the species at the time
it was listed are included in a critical habitat designation if they
contain physical or biological features (1) which are essential to the
conservation of the species and (2) which may require special
management considerations or protection. For these areas, critical
habitat designations identify, to the extent known using the best
scientific and commercial data available, those physical or biological
features that are essential to the conservation of the species (such as
space, food, cover, and protected habitat). In identifying those
physical and biological features within an area, we focus on the
principal biological or physical constituent elements (primary
constituent elements such as roost sites, nesting grounds, seasonal
wetlands, water quality, tide, soil type) that are essential to the
conservation of the species. Primary constituent elements are the
elements of physical or biological features that are the specific
components that provide for a species' life-history processes, and are
essential to the conservation of the species.
Under the second prong of the Act's definition of critical habitat,
we can designate critical habitat in areas outside the geographical
area occupied by the species at the time it is listed, upon a
determination that such areas are essential for the conservation of the
species. For example, an area formerly occupied by the species but that
was not occupied at the time of listing may be essential to the
conservation of the species and may be included in a critical habitat
designation. We designate critical habitat in areas outside the
geographical area occupied by a species only when a designation limited
to its current occupied range would be inadequate to ensure the
conservation of the species.
Section 4 of the Act requires that we designate critical habitat on
the basis of the best scientific and commercial data available.
Further, our Policy on Information Standards Under the Endangered
Species Act (published in the Federal Register on July 1, 1994 (59 FR
34271)), the Information Quality Act (section 515 of the Treasury and
General Government Appropriations Act for Fiscal Year 2001 (Pub. L.
106-554; H.R. 5658)), and our associated Information Quality
Guidelines, provide criteria, establish procedures, and provide
guidance to ensure that our decisions are based on the best scientific
data available. They require our biologists, to the extent consistent
with the Act and with the use of the best scientific data available, to
use primary and original sources of information as the basis for
recommendations to designate critical habitat.
When we are determining which areas we should designate as critical
habitat, our primary source of information is generally the information
developed during the listing process for the species. Additional
information sources
[[Page 20069]]
may include articles published in peer-reviewed journals, conservation
plans developed by States and Counties, scientific status surveys and
studies, biological assessments, or other unpublished materials and
expert opinion or personal knowledge.
Habitat is often dynamic, and species may move from one area to
another over time. Furthermore, we recognize that critical habitat
designated at a particular point in time may not include all of the
habitat areas that we may later determine are necessary for the
recovery of the species, considering additional scientific information
may become available in the future. For these reasons, a critical
habitat designation does not signal that habitat outside the designated
area is unimportant or may not be needed for recovery of the species.
Areas that are important to the conservation of the species, both
inside and outside the critical habitat designation, will continue to
be subject to: (1) Conservation actions implemented under section
7(a)(1) of the Act; (2) regulatory protections afforded by the
requirement in section 7(a)(2) of the Act for Federal agencies to
insure their actions are not likely to jeopardize the continued
existence of any endangered or threatened species; and (3) the
prohibitions of section 9 of the Act if actions occurring in these
areas may result in take of the species. Federally funded or permitted
projects affecting listed species outside their designated critical
habitat areas may still result in jeopardy findings in some cases.
These protections and conservation tools will continue to contribute to
recovery of this species. Similarly, critical habitat designations made
on the basis of the best available information at the time of
designation will not control the direction and substance of future
recovery plans, HCPs, or other species conservation planning efforts if
new information available at the time of these planning efforts calls
for a different outcome.
Prudency Determination
Section 4(a)(3) of the Act, as amended, and implementing
regulations (50 CFR 424.12), require that, to the maximum extent
prudent and determinable, the Secretary designate critical habitat at
the time a species is determined to be an endangered or threatened
species. Our regulations (50 CFR 424.12(a)(1)) state that the
designation of critical habitat is not prudent when one or both of the
following situations exist: (1) The species is threatened by taking or
other human activity, and the identification of critical habitat can be
expected to increase the degree of threat to the species, or (2) such
designation of critical habitat would not be beneficial to the species.
There is currently no operative threat to lesser prairie-chickens
attributed to unauthorized collection or vandalism, and identification
and mapping of critical habitat is not expected to initiate any such
threat. Thus, we conclude designating critical habitat for the lesser
prairie-chicken is not expected to create or increase the degree of
threat to the species due to taking.
Conservation of lesser prairie-chickens and their essential
habitats will focus on, among other things, habitat management,
protection, and restoration, which will be aided by knowledge of
habitat locations and the physical or biological features of the
habitat. In the absence of finding that the designation of critical
habitat would increase threats to a species, if there are any benefits
to a critical habitat designation, then a prudent finding is warranted.
We conclude that the designation of critical habitat for the lesser
prairie-chicken will benefit the species by serving to focus
conservation efforts on the restoration and maintenance of ecosystem
functions within those areas considered essential for achieving its
recovery and long-term viability. Other potential benefits include: (1)
Triggering consultation under section 7(a)(2) of the Act in new areas
for actions in which there may be a Federal nexus where consultation
would not otherwise occur because, for example, the area is or has
become unoccupied or the occupancy is in question; (2) focusing
conservation activities on the most essential features and areas; (3)
providing educational benefits to State or county governments or
private entities; and (4) preventing inadvertent harm to the species.
Therefore, because we have determined that the designation of
critical habitat will not likely increase the degree of threat to the
species and may provide some benefit, we find that designation of
critical habitat is prudent for the lesser prairie-chicken.
Critical Habitat Determinability
Having determined that designation is prudent, under section
4(a)(3) of the Act we must find whether critical habitat for the
species is determinable. Our regulations at 50 CFR 424.12(a)(2) state
that critical habitat is not determinable when one or both of the
following situations exist:
(i) Information sufficient to perform required analyses of the
impacts of the designation is lacking, or
(ii) The biological needs of the species are not sufficiently well
known to permit identification of an area as critical habitat. When
critical habitat is not determinable, the Act allows the Service an
additional year following publication of a final listing rule to
publish a final critical habitat designation (16 U.S.C.
1533(b)(6)(C)(ii)).
In accordance with section 3(5)(A)(i) and 4(b)(1)(A) of the Act and
the regulations at 50 CFR 424.12, in determining which areas occupied
by the species at the time of listing to designate as critical habitat,
we consider the physical and biological features essential to the
conservation of the species which may require special management
considerations or protection. These include, but are not limited to:
(1) Space for individual and population growth and for normal
behavior;
(2) Food, water, air, light, minerals, or other nutritional or
physiological requirements;
(3) Cover or shelter;
(4) Sites for breeding, reproduction, and rearing (or development)
of offspring; and
(5) Habitats that are protected from disturbance or are
representative of the historical geographical and ecological
distributions of a species.
We are currently unable to identify critical habitat for the lesser
prairie-chicken because important information on the geographical area
occupied by the species, the physical and biological habitat features
that are essential to the conservation of the species, and the
unoccupied areas that are essential to the conservation of the species
is not known at this time. A specific shortcoming of the currently
available information is the lack of data about: (1) The specific
physical and biological features essential to the conservation of the
species; (2) how much habitat may ultimately be needed to conserve the
species; (3) where the habitat patches occur that have the best chance
of rehabilitation; and (4) where linkages between current and future
populations may occur. Additionally, while we have reasonable general
information about habitat features in areas occupied by lesser prairie-
chickens, we do not know what specific features, or combinations of
features, are needed to ensure persistence of stable, secure
populations.
Several conservation actions are currently underway that will help
inform this process and reduce some of the current uncertainty.
Incorporation of the information from these conservation actions will
give us a better
[[Page 20070]]
understanding of the species' biological requirements and what areas
are needed to support the conservation of the species.
The five State conservation agencies within the occupied range of
the lesser prairie-chicken, through coordination with the Western
Association of Fish and Wildlife Agencies Grassland Initiative, were
funded to develop a rangewide survey sampling framework and to
implement aerial surveys in 2012 and 2013. The rangewide plan commits
to continued rangewide population monitoring of the lesser prairie-
chicken, including annual use of the aerial survey methodology used in
2012 and 2013 (Van Pelt et al. 2013, p. 122). Ongoing implementation of
these aerial surveys is important, as they may enable biologists to
determine location of leks that are too distant from public roads to be
detected during standard survey efforts. Our critical habitat
determination will benefit from this additional information and allow
us to consider the most recent and best science in making our critical
habitat determination.
Similarly, all five State conservation agencies within the occupied
range of the lesser prairie-chicken have partnered with the Service and
Playa Lakes Joint Venture, using funding from the DOE and the Western
Governors' Association, to develop a decision support system that
assists in evaluation of lesser prairie-chicken habitat, assists
industry with nonregulatory siting decisions, and facilitates targeting
of conservation activities for the species. The first iteration of that
product went online in September 2011 (http://kars.ku.edu/geodata/maps/sgpchat/). This decision support system is still being refined, and a
second iteration of the product, under oversight of the Western
Association of Fish and Wildlife Agencies, went online during the fall
of 2013. Further iterations will provide additional information that
will help improve evaluation of lesser prairie-chicken habitat. The
Steering Committee of the Great Plains Landscape Conservation
Cooperative has made completion of Phase II one of their highest
priorities for the next 18 months. The Lesser Prairie-chicken
Interstate Working Group will be identifying the research and data
needs for moving Phase II forward. Outputs derived from this decision
support tool will help us more precisely identify the location and
distribution of features essential to the conservation of the lesser
prairie-chicken.
Therefore, we have concluded that critical habitat is not
determinable for the lesser prairie-chicken at this time because we
lack information on the precise area occupied by the species and on the
physical and biological habitat features that are essential to the
conservation of the species. Also, since the unoccupied areas that are
essential to the conservation of the species are not known at this
time, we lack information to assess the impacts of the potential
critical habitat designation.
Required Determinations
National Environmental Policy Act (42 U.S.C. 4321 et seq.)
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.), need not be
prepared in connection with listing a species as an endangered or
threatened species under the Endangered Species Act. We published a
notice outlining our reasons for this determination in the Federal
Register on October 25, 1983 (48 FR 49244).
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994
(Government-to-Government Relations with Native American Tribal
Governments; 59 FR 22951), Executive Order 13175 (Consultation and
Coordination With Indian Tribal Governments), and the Department of the
Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with recognized Federal
Tribes on a government-to-government basis. In accordance with
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights,
Federal-Tribal Trust Responsibilities, and the Endangered Species Act),
we readily acknowledge our responsibilities to work directly with
tribes in developing programs for healthy ecosystems, to acknowledge
that tribal lands are not subject to the same controls as Federal
public lands, to remain sensitive to Indian culture, and to make
information available to tribes.
By letter dated April 19, 2011, we contacted known tribal
governments throughout the historical range of the lesser prairie-
chicken. We sought their input on our development of a proposed rule to
list the lesser prairie-chicken and encouraged them to contact the
Oklahoma Ecological Services Field Office if any portion of our request
was unclear or to request additional information. We did not receive
any comments regarding this request. We continued to keep tribal
governments informed by providing notifications of each new or reopened
public comment period and specifically requesting their input. We did
not receive any requests or comments as a result of our request.
References Cited
A complete list of all references cited in this rule is available
on the Internet at http://www.regulations.gov, or upon request from the
Field Supervisor, Oklahoma Ecological Services Field Office (see FOR
FURTHER INFORMATION CONTACT).
Authors
The primary authors of this rule are the staff members of the
Oklahoma Ecological Services Field Office (see FOR FURTHER INFORMATION
CONTACT).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as set forth below:
PART 17--[AMENDED]
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245, unless
otherwise noted.
0
2. Amend Sec. 17.11(h) by adding an entry for ``Prairie-chicken,
lesser'' in alphabetical order under BIRDS to the List of Endangered
and Threatened Wildlife to read as follows:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
[[Page 20071]]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
-------------------------------------------------------- population where When Critical Special
Historic range endangered or Status listed habitat rules
Common name Scientific name threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Birds
* * * * * * *
Prairie-chicken, lesser.......... Tympanuchus U.S.A. (CO, KS, NM, Entire............. T 831 NA 17.41 (d)
pallidicinctus. OK, TX).
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * *
Dated: March 21, 2014.
Daniel M. Ashe,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 2014-07302 Filed 4-9-14; 8:45 am]
BILLING CODE 4310-55-P