Picoides borealisred-cockaded woodpecker

Geographic Range

The Red-cockaded woodpecker is found in the Southeastern United States. Populations are distributed as far west as Oklahoma and Texas, north to Kentucky, south into Florida and east to the Alantic Ocean. Primarily concentrated in certain old-growth pine forests. (Poole et al., 1994; Winkler et al., 1995)

Habitat

These woodpeckers are adapted to mature, living, open-pine forests that are frequently maintained by naturally occurring summer fires. They are particularly dependent on a few species of pinewith substantially strong heartwood. Older trees (70 years or more) are preferred. Species utilized include longleaf (Pinus palustris), slash (P. elliottii), shortleaf (P. echinata), pond (P. serotina) and pitch (P. rigada) pines. (Poole et al., 1994; Short, 1982; Winkler et al., 1995)

Physical Description

Length: 20 to 23 cm Small, white and black woodpecker with a barred back. This characteristic distinguishes it from all other species of the same genus within its range. Large white feathers overlie the ears and cheek area. Underside white or grayish, with notable black spots along the sides of the breast. Male has red spots located on each side of the nape that are seldomly exposed. Female is slightly larger and lack red spots.

(Poole et al., 1994; Short, 1982)

  • Average mass
    56 g
    1.97 oz
    AnAge

Reproduction

Picoides borealis is monogamous and pair bonding takes place throughout the year, whenever a female arrives in an unoccupied cavity cluster or nesting site. They partake in cooperative breeding, and a pair may or may not have helpers, which are usually male. Males are able to breed at one year, but breeding is usually delayed because young males are serving as helpers in their own natal group. Copulation can be seen at any time, increasing in occurrence in late spring. The first brood is laid between April and June, and a second brood in the same season is rare. The clutch contains 2-5 eggs. Incubation is done by both parents and usuallly begins after the second egg is laid, with the breeding male remaining on the nest throughout the night. Incubation lasts 10-13 days. Both parents feed the nestlings and development is rapid. Most chicks fledge after 26-29 days, but commonly remain dependent on the parents for up to 5 months. The nest is located in the roost cavity of the breeding male. These cavities are excavated in mature pines between 12-100 feet up. They are 8-12 inches deep, with a 2 inch diameter entrance that tilts upward to prevent pitch and water from entering the nest.

(Poole et al., 1994; Short, 1982; Winkler et al., 1995)

  • Average eggs per season
    3
    AnAge
  • Average time to hatching
    12 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    240 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    240 days
    AnAge

Lifespan / Longevity

Behavior

Picoides borealis is non-migratory, sedentary and very gregarious. It resides in small family groups (from 2-10 individuals) that remain in close contact with each other. These groups are referred to as "clans. This bird, at first glance, seems to be exceedingly irritable because of its loud, harsh vocal calls. In fact, an early name for it was Picus querulus. P. borealis is now known to be a very social bird, using these vocalizations for communication. The most commmon calls are for self-announcement and alarm. Churt notes are given when the bird is located in its natural surroundings and it is unaware of human or predator presence. The sklit note is given when the bird is in a state of annoyance or disturbance. Other vocalizations include wicka, rattle and chortle calls. These represent excitedness, self-presence, and greetings, respectively. Vocal exchanges are more common in social groups, and in P. borealis they occur most often when birds are leaving or returning to a cavity.

(Poole et al., 1994; Wnkler et al., 1995)

Communication and Perception

Food Habits

Picoides borealis is omnivorous, and its diet consists mainly of adult, larvae and eggs of tree surface and subsurface arthropods, especially beetle larvae and ants. Usually forages for food on pine trees by ripping loose bark from the surface with an upward or sideways movement of the bill or in some cases, bark is stripped away with the feet. To a lesser extent, various seeds, nuts (pecans) and fruit are consumed, and occasionally the woodpecker frequents cornfields in search of earworms in a certain larval stage that are residing within the corn kernel. (Bent, 1992; Poole et al., 1994; Short, 1982; Winkler et al., 1995)

Economic Importance for Humans

Economic Importance for Humans: Negative

Many woodpeckers are notorious for excavating holes in such things as utility poles, fence posts and even houses, but P. borealis is very restricted in habitat, limiting any negative effects on humans. In most cases, however, the pine tree that it resides in with its clan usually dies due to the extensive excavating for nests and roosting sites. (Poole et al., 1994; Skutch, 1985)

Conservation Status

Due to its dependence on particular southern pine forests for food and habitat, the Red-cockaded woodpecker has been considered endangered since 1968. Habitat fragmentation, clear-cutting, midstory encroachment of hardwood and natural disasters, including Hurricane Hugo in 1989, have been the major causes of the devastating decline in this species. Remaining populations are concentrated on federal and private lands with the largest located on state land in Florida. There have been two recovery plans written to conserve and rebuild the populations of the woodpecker. One was established in 1979, but was never fully acted upon. Then, in 1985 the U.S. Fish and Wildlife Service introduced a slightly revised plan. It was based heavily on research by Fish and Wildlife Service biologists on the then largest, healthiest population, located in the Francis Marion National Forest. This plan omitted some sugestions from the previous 1979 plan, including the idea of linking fragmented populations with corridors made from interstate highways, and added others. The general objective of the revised plan was to ultimately achieve range-wide recovery. A specific objective objective was to establish a viable population that consisted of a minimum effective population size of 500 breeding birds. This would maintain desired levels of genetic variation for long-term population survival. The potential carrying capacity was calculated for different areas. Each carrying capacity depended on species compostion, structure and age of forest habitats available. The approximate overall capacity ranged from one clan per 400 acres of habitat to one clan per 200-250 acres of habitat. The American Ornithologist Union highly criticised the efforts of the Fish and Wildlife Service. One of the reported problems was their estimation of the species minimum viable population size. Some argued that the estimation should be 1,018 breeding birds, which in turn, would increase the habitat to 25,450 ha of pine forest, a much larger calculation than suggested by the revised plan. Despite the arguments, this plan has not been changed and no new plan has been written.

Recently, however, new approaches to conservation including old cavity restoration, artificial cavity construction, and the introduction of females into isolated groups, have made some positive advancments towards the increase in populations. The total population is now estimated at about 7,500 individuals.

(Poole et al., 1994; Winkler et al., 1995; U.S. Fish and Wildlife Service, 1985)

Other Comments

As mentioned before the Red-cockaded woodpecker nests and roosts in mature pines, but the cavities are also notable because of their peculiar features. Around the cavity entrance the bird drills many small holes, allowing a sticky sap to flow freely from the openings. The bird also strips away the bark surrounding the entrance. By doing this, the resin and the smooth trunk create a defense against aboreal snakes, one of the birds' major predators.

Contributors

Danette Beattie (author), University of Michigan-Ann Arbor.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

References

Bent, Arthur Cleveland. 1992. Life Histories of North American Woodpeckers. Indiana University Press, Indianapolis.

Poole, A. and F. Gill, eds. 1994. The Birds of North America, No. 85. The American Ornithologists Union and the Academy of Natural Sciences of Philadelphia, Pennsylvania.

Short, Lester T. 1982. Woodpeckers of the World. Delaware Museum of Natural History, Delaware.

Skutch, Alexander F. 1985. Life of the Woodpecker. Ibis Publishing Company, California.

Winkler, Hans, David A. Christie and David Nurney. 1995. Woodpeckers: A Guide to the Woodpeckers of the World. Houghton Mifflin Company, New York.

U.S. Fish and Wildlife Services. 1985. Red-cockaded Woodpecker Recovery Plan. U.S. Fish and Wildlife Service, Georgia.