Hesperia leonardus montana

Pawnee Montane Skipper

FWS Focus

Overview

Characteristics
Overview

The Pawnee montane skipper is a species with a narrow distribution that is endemic to Colorado. Fire suppression, development of dams and reservoirs and climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.

Learn more about climate change
are all threats to the persistence and recovery of this federally threatened species, as noted in the 2020 amendment to the recovery plan.

Scientific Name

Hesperia leonardus montana
Common Name
Pawnee Montane Skipper
FWS Category
Insects
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Habitat

Characteristics
Habitat

The skippers occur in dry, open ponderosa pine (Pinus ponderosa) woodlands at an elevational range of 6,000 to 7,500 feet. The slopes are moderately steep with soils derived from Pikes Peak granite as described in the recovery plan from 1998. The understory is limited in the pine woodlands. Blue grama grass (Bouteloua gracilis) and prairie gayfeather (Liatris punctata) are two necessary components of the ground cover strata. Blue grama grass is the primary plant for egg deposition, larvae feeding, larvae overwintering and pupation. The prairie gayfeather is the primary nectar plant for adult skippers, as noted in the 5-year review in 2011. The 1998 recovery plan notes that small clumps of blue grama occur throughout the warm, open slopes inhabited by skippers and that prairie gayfeather occurs throughout the ponderosa pine woodlands. Skippers are very uncommon in pine woodlands with a tall shrub understory or where young conifers dominate the understory.

The optimum skipper conditions are a tree canopy cover of 25% from ponderosa pine and 5% from Douglas fir (Pseudotsuga menziesii), as noted in the 5-year review in 2011. In a 1986 status report that was produced by ERT Company, other general characteristics of Pawnee montane skipper habitat include:

  • Tree density of less than 120 trees per acre in a size class of 0 to 5 feet (0 to 152 centimeters) diameter at breast height and overall tree density of less than 200 per acre (per 0.4 hectare)
  • Shrub and grass cover generally less than 10%
  • Prairie gayfeather flower stem density ranging from 50 to 500 per acre (per 0.4 hectare)
  • Blue grama cover 5% or less, but present across the landscape

The skipper’s narrow range is inherently restricted by the area of overlap between the northern extension of the ponderosa pine/blue grama grass community and the southern extension of the prairie gayfeather, as noted in the recovery plan. The total area of skipper habitat is approximately 25,044 acres, of which 13,826 acres occur on the Pike National Forest as noted in the recovery plan.

Forest

A dense growth of trees and underbrush covering a large tract.

Characteristic category

Food

Characteristics
Food

The skipper has two main plants upon which it feeds, blue grama grass (Bouteloua gracilis), used by larvae, and prairie gayfeather (Liatris punctata), from which adults get their nectar (Liatris pycnostachya), noted in the 5-year review in 2011. Other plants noted as occasional nectar sources include smooth asters (Aster laevis), in upland areas and along gully bottoms where soil moisture is greater, and musk thistle (Carduus nutans), which is especially important along river bottom edges and up some ravines, as noted in the recovery plan. Females of this skipper species were observed along the South Platte River in large numbers on musk thistle, as documented by Opler in 1986. The Colorado Department of Agriculture includes musk thistle among its List B species of noxious weeds, which means that it is a species for which the Commissioner of Agriculture develops and implements state noxious weed management plans, in consultation with the state noxious weed advisory committee, local governments and other interested parties, to stop their continued spread. Other plants occasionally used by Pawnee montane skippers include Canada thistle (Cirsium arvense), bee balm (Monarda spp.), pineywoods geranium (Geranium caespitosum), sunflower (Helianthus spp.), Senecio (Senecio spp.), as documented in the 5-year review. J.R. Sovell documented in 2018 that false goldenaster (Heterotheca villosa) is particularly important when prairie gayfeather is sparse or absent.

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The Pawnee montane skipper is a small butterfly with a wingspan slightly more than 1 inch (2.54 centimeters).

Color & Pattern

The Pawnee montane skipper is a small, brownish-yellow butterfly with a wing span slightly more than 1 inch (2.54 centimeters). Small, dull brownish-yellow, usually distinct spots occur near the outer margins of the upper surface of the wings, while one to four distinct brownish to off-white spots occur on the lower surface of the wings. The ventral spots are larger on the hind wing and are generally whiter on the female butterfly.

Characteristic category

Life Cycle

Characteristics
Life Cycle

Pawnee montane skippers emerge from their pupae as adult butterflies in late July. Usually, males emerge before females by an average of seven to 10 days. Adult emergence and flight period coincides with the flowering period for prairie gayfeather, as documented by ERT Company in 1986, with the primary flight period occurring from late August to early September, as documented by the amendment to the recovery plan in 2020. The species overwinters as young larvae; little is known about the larval and pupal stages, as noted in the 1998 recovery plan. Pupation is generally short, 13 to 23 days, in most butterfly species. The skipper completes its life cycle - egg to larva to pupa to adult butterfly to egg - annually, as L.D. Keenan and others documented in 1986.

Reproduction

Adult females deposit eggs singly and directly on leaves of blue grama grass, the larval food plant, as documented by J.A. Scott and R.E. Stanford in 1982, as well as W.D. McGuire in 1982, and later by P.A. Opler in 1986.

Geography

Characteristics
Range

The Pawnee montane skipper occurs only in the South Platte Canyon River drainage system in Colorado, in portions of Jefferson, Douglas, Teller and Park counties, as noted in the 1998 recovery plan.

Launch Interactive Map

Timeline

Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.

8 Items

Listing

Critical Habitat

Listing

Listing

Five Year Review

Five Year Review

Recovery Plan

Five Year Review

1750
1760
1770
1780
1790
1800
1810
1820
1830
1840
1850
1860
1870
1880
1890
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
2020
2030
2040
2050
2060
2070
2080
2090
2100
2110
2120
2130
2140
2150
2160
2170
2180
2190
2200
2210
2220
2230
2240
1956
1957
1958
1959
1961
1962
1963
1964
1965
1966
1967
1968
1969
1971
1972
1973
1974
1975
1976
1977
1978
1979
1981
1982
1983
1984
1985
1986
1987
1988
1989
1991
1992
1993
1994
1995
1996
1997
1998
1999
2001
2002
2003
2004
2005
2006
2007
2008
2009
2011
2012
2013
2014
2015
2016
2017
2018
2019
2021
2022
2023
2024
2025
2026
2027
2028
2029
2031
2032
2033
2034
2035
2036
2037
2038
2039
2041
2042
2043
2044
2045

Listing

Jul 3, 1978

Jul 3, 1978 Listing (Endangered)
Proposed Endangered or Threatened Status with Critical Habitat For Ten Butterflies or Moths
  • Publication type: Proposed
Item 1

Critical Habitat

Jul 3, 1978

Jul 3, 1978 Critical Habitat
Proposed Endangered or Threatened Status with Critical Habitat For Ten Butterflies or Moths
  • Publication type: Proposed
Item 2

Listing

Sep 25, 1986

Sep 25, 1986 Listing (Threatened)
Thr. Status for Pawnee Montane Skipper; 51 FR 34106-34109
  • Publication type: Proposed
Item 3

Listing

Sep 25, 1987

Sep 25, 1987 Listing (Threatened)
Final Rule to Determine Pawnee Montane Skipper (Hesperia leonardus montana) to be Thr. Species; 52 F…
  • Publication type: Final
Item 4

Five Year Review

Oct 6, 2008

Oct 6, 2008 Five Year Review (Information Solicitation)
5-Year Reviews of Three Wildlife Species and Eight Plant Species in the Mountain-Prairie Region
  • Publication type: Notice
Item 5

Five Year Review

Apr 12, 2019

Apr 12, 2019 Five Year Review (Information Solicitation)
Initiation of 5- Year Status Reviews of 6 Species in the Mountain-Prairie Region; request for inform…
  • Publication type: Notice
Item 6

Recovery Plan

Aug 6, 2019

Aug 6, 2019 Recovery Plan (Document Availability (non-FR))
21 Draft Recovery Plan Revisions for 25 Species in 15 States Across the United States; Notice of Ava…
  • Publication type: Draft
Item 7

Five Year Review

Mar 13, 2023

Mar 13, 2023 Five Year Review (Information Solicitation)
Endangered and Threatened Wildlife and Plants; Initiation of 5-Year Status Reviews of 27 Listed Spec…
  • Publication type: Notice
Item 8