Red-cockaded Woodpecker

The RCW is highly sedentary compared to most other birds. Adult helper males disperse the shortest distance to nearby territories, as seen in the North Carolina Sandhills (median 1.27 kilometers, 0.79 mile) (Kesler et al. 2010). Juveniles exhibit 2 dispersal behaviors following prospecting forays from their natal territory (Pasinelli and Walters 2002, Kesler et al. 2010). In the prevailing short distance mode, juvenile males and females moved a median, respectively, of 2.94 kilometer (1.83 miles) and 3.31 kilometer (2.06 miles) in the Sandhills (Kesler et al. 2010). Following extraterritorial forays at much greater distances than their normal forays, some juveniles engaged a less frequent jumper behavior to acquire positions at other territories at a mean distance of 9.9 kilometers (6.15 miles) from their natal territory (Kesler et al. 2010).

Excavation of cavities in live pines has given rise to additional unusual and complex behaviors, ranging from cooperative breeding (Walters et al. 1992) to daily excavation of resin wells to create resin barriers against predatory North American rat snakes (Pantherophis sp., Ligon 1970, Dennis 1971, Jackson 1974, 1978, Rudolph et al. 1990). Use of live pines is also the primary reason why the species requires mature pines, the loss of which has resulted in endangerment.  Excavation of cavities in live pines is an amazingly difficult task. Birds must first select a suitable old pine (Jackson and Jackson 1986, Conner and O’Halloran 1987, DeLotelle and Epting 1988, Rudolph and Conner 1991), then excavate an entrance tunnel through 10 to 15 centimeters (4 to 6 inches) of live sapwood, avoiding dangerous pine resin that seeps from the wood, and finally construct a cavity chamber within the heartwood (Jackson 1977, Hooper et al. 1980, Conner and Locke 1982, Conner and O’Halloran 1987, Hooper 1988, Hooper et al. 1991). The time required to excavate a cavity varies greatly, but excavation typically takes many years

(Jackson et al. 1979, Rudolph and Conner 1991, Conner and Rudolph 1995).  

Methods of foraging include flaking away bark and probing under the bark using their specialized forked tongue to extract insects. Large, older trees are preferred for foraging. In general, males forage on the limbs and upper trunk while females forage on the trunk below the crown. This division of foraging area is most noticeable in winter when insect numbers are at their lowest and their activity slows due to cold weather, making it harder for RCWs to detect prey. Differences in the foraging behavior of males and females may help to reduce competition between them when food is scarce.

Alexander Wilson gave the species the English common name we use today, red-cockaded woodpecker, in reference to the several red feathers of males, located between the black crown and white cheek patch, which are briefly displayed when the male is excited. In Wilson’s time, cockade was a common term for a ribbon or other ornament worn on a hat as a badge. The cockade is a poor field mark because it is rarely seen in the field, but it does identify the sexes of adult birds in the hand.

Adults and Juveniles

• Black and white with a ladder back
• Large white cheek patches that distinguish the species from all other woodpeckers in their range
• Black above with black and white barring on their backs and wings
• Breasts and bellies are white to grayish white with distinctive black spots along the sides of the breast changing to bars on the flanks
• Central tail feathers are black and outer tail feathers are white with black barring

Adults

• Black crowns
• Narrow white line above the black eye
• Heavy black stripe separating the white cheek from a white throat
• White to grayish or buffy nasal tufts
• Bills are black, and legs are gray to black
• Males have several red feathers, located between the black crown and white cheek patch. The small cockade is not normally visible beneath crown feathers.
• Excepting the red cockade, the species is monomorphic and the sexes are generally indistinguishable in the field

Juveniles

• Females have all black crowns, but males have red crown patches
• May have duller plumage than adults, the presence of white flecks just above the bill on the forehead and diffuse black shading in the white cheek patch

Nestlings

• Nestling female capital feather tracks, observed through the transparent skin before feather emergence, appear grayish black
• Nestling male capital feather tracks appear reddish

Red-cockaded woodpeckers are most known for their raspy sklit. However, other calls can be heard including a churt, which is repeated every 2 to 4 seconds, when flying into a roosting and nesting area, as well as a rattle that ends with a drop in pitch. Foraging birds give a soft, melodious chortling call when close to each other, as noted by Cornell Lab of Ornithology in 2019.

Red-cockaded woodpeckers are relatively small. They are larger than downy woodpeckers (Picoides pubescens), similar in size to yellow-bellied sapsuckers (Sphyrapicus varius) and smaller than other southeastern woodpeckers. Sizes vary based geographically and clinally, meaning a gradual change in a character or feature across the distributional range of a species or population, with larger birds generally to the north, as documented by R.M. Mengel and J.A. Jackson in 1977.

Measurements
Length of adults: 20 to 23 cm (8 to 9 in)
Wingspan of adults: About 35 to 38 cm (14 to 15 in)

Nestlings
Aged according to descriptive characteristics of Day 0 to Day 19 set out by J.D. Ligon in 1970 and depicted in Table 20 of the U.S. Fish and Wildlife Service 2003 recovery plan.

Day 0:

• Skin - Loose and pink
• Bill - Mandible roughly 2 mm longer that maxilla; diamond-shaped egg-tooth on maxilla
• Wings - Permanently extended and used to remain upright
• Retrices – Bumps, Feet - Heel pad greatly enlarged
• Size - Appears small enough to fit back into egg.

Day 19:

• Retrices - Longest feather 29 mm and quills beginning to break away
• Remiges - Longest primary 45 mm and quills beginning to break away
• Tracts - Body covered with feathers except for abdomen and flanks.

Adults weigh roughly 40 to 55 grams (1.5 to 1.75 ounces).

The mortality pattern is typical of cooperatively breeding avian species. It is characterized by relatively low survival during the first year, especially of dispersers; relatively high survival of breeders and helpers and senescence at the end of the life span.  Compared to non-cooperative species, survival of both juveniles and adults is high, and the life span is long.

A bird of its size residing in temperate regions, this species exhibits exceptionally high survival rates. Survival rates of adult male helpers and breeders generally are about 5% higher than that of breeding females. There is distinct geographic variation in survival similar to that observed for partial brood loss. Survival rates are about 75% for males and 70% for females in the northern, inland population in the North Carolina Sandhills, about 80% and 75% respectively in coastal populations in North Carolina and 86% and 80%, respectively, in the Florida panhandle. Such an association between increased survival and reduced fecundity, meaning the ability to produce an abundance of offspring, is common in animal life histories.

A captive female lived to 17 years, noted J. Jackson, and the maximum ages recorded for wild birds are 18 for males and 17 for females.

The peak reproductive years for this species are from ages 4 to 8. Breeding season begins in April and lasts through July. Generally clutches contain two to four eggs, although the full range is one to five eggs. Co-breeding females produce clutches as large as eight eggs, but more typically produce five to seven. Variation exist among populations in clutch size, with population averages ranging from 2.9 to 3.5 eggs, but there does not appear to be a regular geographic pattern in this variation.

In 1970, J.D. Ligon documented that incubation begins before the clutch is complete and eggs hatch asynchronously.  The number of young fledged from successful nests is typically one to four. Broods of five fledglings occur occasionally in the North Carolina Sandhills at the northern edge of the their range, whereas the maximum brood size recorded at Eglin Air Force Base, Florida in the southern part of the range is three fledglings, as documented by R.N. Conner and others in 2001.

The first several days after fledging, the young birds are somewhat reluctant to fly, and spend considerable time perched high in the pines, clinging to the trunk or large limbs. By the end of their first week out of the nest, however, the young are much more active and move with the adults as the group travels through the territory. There is an abrupt transition between the targeted feedings that characterize the first nine days after fledging to approach feedings from day 10 onwards, as documented by E.L. Ragheb and J.R. Walters in 2011. The fledglings gradually begin to obtain food for themselves but continue to beg for food and squabble with each other for some time. Young are sometimes observed being fed two months after fledging and are occasionally seen begging as late as the subsequent winter, as documented by J.D. Ligon in 1970.

Young birds may either disperse in their first year, or they may remain on the natal territory and become a helper. The proportion of each sex adopting each strategy varies among populations, as noted by M.R. Lennartz and others in 1987 and later confirmed by several researchers. That said, first-year dispersal is the dominant strategy for females, whereas both strategies are common among males. A dispersing individual, if it survives, may become a breeder at age one, but many fail to locate a breeding vacancy and exist as a floater at age one. In a few cases these individuals act as a helper in a new group, as documented by J.R. Walters in 1988 and 1992 and confirmed by later research with V. Garcia in 2016. Some dispersing males locate a territory but not mate, and hence are solitary males at age one. Solitary males and floaters, like helpers, may become breeders at subsequent breeding seasons.

Red-cockaded woodpeckers are cooperative breeders. A breeding group consists of the breeding male and female with six or fewer non-breeding adult helpers. Each individual occupies its own cavity which is excavated into the heartwood of living pines that are at least 65 to 80 years old and typically much older. Each group defends its territory of cavity trees and foraging habitat from other groups. A single group territory and home range where birds forage for invertebrates on and under the bark of larger and older living pines may be upwards to 162 hectares (400 acres), though much less depending on habitat quality and neighboring group density.

In mid-April, the female usually lays a clutch of three to five white eggs in the breeding male’s roost cavity. Eggs hatch after 10 to 12 days of incubation - which is among the shortest incubation in birds - and nestlings fledge from the nest cavity 24 to 27 days after hatching. Red-cockaded woodpecker nestlings are altricial, that is, they do not have feathers when hatched and their eyes are not open. They require a lot of care from parents and helpers who will feed the nestlings and clean the cavity of waste during the nestling period. In contrast, quail are precocial, meaning that they hatch fully feathered and are able to feed themselves when led to food by the parent.

After fledging, the young birds continue to be fed by adults for up to six months, at which time the majority of fledglings disperse from the territory where they hatched. Mortality is high for female fledglings, 68%, as they disperse to search for breeding vacancies. Male fledglings either disperse or remain on their natal territory to become helpers. Annual mortality is also high for male fledglings, at 57%.

Although re-nesting may occur if a clutch or brood is lost, red-cockaded woodpeckers typically have only one successful nesting attempt annually. Double brooding, or two successful nests in one breeding season, has been documented but is extremely rare.

Longleaf pines (Pinus palustris) are most commonly preferred, but other species of southern pine are also acceptable. Cavities are excavated in mature pines, generally more than 80 years old. The older pines favored by red-cockaded woodpeckers often suffer from a fungus called red heart disease which attacks the center of the trunk, and causes the inner wood - the heartwood - to become soft. Cavity excavation takes one to six years. The aggregate of cavity trees is called a cluster and may include one to 20, or more, cavity trees on 3 to 60 acres. The average cluster is about 10 acres. Cavity trees that are being actively used have numerous, small resin wells which exude sap.

The birds keep the sap flowing apparently as a cavity defense mechanism against rat snakes and possibly other predators. The typical territory for a group ranges from about 125 to 200 acres, but observers have reported territories running from a low of around 60 acres, to an upper extreme of more than 600 acres. The size of a particular territory is related to both habitat suitability and population density.

More than 75% of the diet of red-cockaded woodpecker consists of arthropods, especially ants and cockroaches, but also includes beetles, spiders, centipedes, true bugs, crickets and moths, as documented by W.W. Beal and others in 1941 and confirmed by several researchers. Fruits and seeds make up a small portion of the adult diet. Red-cockaded woodpeckers have been known to eat the fruits or seeds of pines (Pinus spp.), poison ivy (Rhus radicans), magnolia (Magnolia spp.), wax myrtle (Myrica spp.), wild cherry (Prunus serotina), wild grape (Vitus spp.), blueberry (Vaccinum spp.) and blackgum (Nyssa sylvatica). The diet of nestlings also consists principally of arthropods, with fruits being a minor component, as documented by W.W. Baker in 1971 and confirmed by several researchers.

The red-cockaded woodpecker is highly sedentary compared to most other birds. Adult helper males disperse the shortest distance to nearby territories, as D.C. Kesler and others observed in 2010 in the North Carolina Sandhills, noting a median 1.27 kilometers (0.79 mile). Juveniles exhibit two dispersal behaviors following prospecting forays from their natal territory, as documented by G. Pasinelli and J.R. Walters in 2002 and later confirmed by D.C. Kesler and others in 2010. They also noted that in the prevailing short distance mode, juvenile males and females moved a median, respectively, of 2.94 kilometer (1.83 miles) and 3.31 kilometer (2.06 miles) in the Sandhills. Following extraterritorial forays at much greater distances than their normal forays, they also observed that some juveniles engaged a less frequent jumper behavior to acquire positions at other territories at a mean distance of 9.9 kilometers (6.15 miles) from their natal territory.

J.R. Walters and others in 1992 documented that excavation of cavities in live pines has given rise to additional unusual and complex behaviors, ranging from cooperative breeding to daily excavation of resin wells to create resin barriers against predatory North American rat snakes (Pantherophis sp.), which J.D. Ligon further noted in 1970 and was later confirmed by several researchers. Use of live pines is also the primary reason why the species requires mature pines - the loss of which has resulted in endangerment. Excavation of cavities in live pines is an amazingly difficult task. Birds must first select a suitable old pine, then excavate an entrance tunnel through 10 to 15 centimeters (4 to 6 inches) of live sapwood, avoiding dangerous pine resin that seeps from the wood, and finally, they must construct a cavity chamber within the heartwood, as documented by J.A. Jackson in 1977 and confirmed by several researchers. Jackson and others also noted that the time required to excavate a cavity varies greatly, but excavation typically takes many years.  

Methods of foraging include flaking away bark and probing under the bark using their specialized forked tongue to extract insects. Large, older trees are preferred for foraging. In general, males forage on the limbs and upper trunk, while females forage on the trunk below the crown. This division of foraging area is most noticeable in winter when insect numbers are at their lowest and their activity slows due to cold weather, which makes it harder for the birds to detect prey. Differences in the foraging behavior of males and females may help to reduce competition between them when food is scarce.