FW 404: Dickinson Ch24

Red-Cockaded Woodpecker

I. Identification and Status

  • Taxonomy and Description: The Red-cockaded woodpecker (RCW) is one of nine Picoides species native to the United States.

    • It is approximately 7 3/4" long.

    • Plumage is distinguished by a black and white barred back, black bars on white outer tail feathers, and a large, wide white cheek patch.

    • Adult males possess small red-cockaded patches (on the posterior sides of the head), which are typically hidden beneath the black plumage and are rarely visible.

  • Status: The RCW was identified as a rare and endangered species in 1968.

II. Distribution and Population Dynamics

  • Distribution: RCWs are found in various habitats throughout the southeastern United States, including longleaf pine, slash pine flatwoods, and shortleaf/Virginia pine forests.

  • Population Decline: The world's population of RCWs has declined by approximately 99% from historic estimates.

  • Current Populations (1998 data):

    • Federal Lands: 3,454 active clusters are known on federal property (52 properties total). However, 79% of these properties have fewer than 10 active clusters.

    • Private Lands: Approximately 969 active clusters are known on private lands across 11 states, though private land populations are generally declining.

III. Habitat and Cavity Ecology

  • Habitat Preference: RCWs prefer pine ecosystems, with longleaf pine-wiregrass communities considered ideal for nesting and foraging.

  • Clusters: RCWs reside in aggregations of cavity trees known as clusters, which usually contain more than 20 trees and typically cover about 10 acres.

  • Cavity Trees: RCWs prefer older pine trees (often 80 or more years old).

    • Trees chosen for excavation suffer from red heart fungus, which softens the heartwood.

    • Cavity construction is a long process, taking anywhere from 1 to 6 or more years.

    • Cavities require 4" to 5" of heartwood for safety, preferably 7" to 8".

  • Defense Mechanism (Resin Wells): RCWs excavate shallow wells around the cavity entrance, which induces resin flow, creating a resin-covered "plate" that helps deter predators like tree-climbing rat snakes.

IV. Life History and Breeding

  • Social Structure: RCWs are cooperative breeders. A group typically defends a territory and consists of a breeding pair and up to four helpers.

    • Helpers are usually male offspring who assist with incubation, brooding, and feeding.

  • Nesting: Breeding begins in late March or early April.

    • Clutch size is generally 3 to 5 eggs.

    • Incubation lasts 10 to 12 days.

  • Diet: The diet is varied but mainly composed of arthropods, including beetles, spiders, centipedes, and other invertebrates. They forage primarily on live, large pine trees.

V. Conservation, Predation, and Management

  • Keystone Species: The RCW is the primary cavity excavator in its ecosystem, creating roosting and nesting cavities used by at least 24 other species of vertebrates and invertebrates.

  • Kleptoparasitism: Cavity usurpation is a significant threat. The Southern flying squirrel and the Red-bellied woodpecker are common usurpers that can adversely affect RCW nesting success.

  • Predation: Predators include rat snakes and possibly climbing squirrels, which feed on eggs and fledglings.

  • Habitat Management:

    • Restoration: Federal guidelines require the establishment of well-stocked pine stands (70 to 90 sq. ft. basal area/acre) and minimum rotations of 100 to 120+ years for pine trees used for foraging and nesting.

    • Burning and Thinning: Prescribed burning (every 2 to 5 years) and timber thinnings are used to maintain the open, park-like conditions necessary for habitat.

    • Artificial Cavities: The successful use of artificial cavities and inserts has been shown to enhance populations and provide necessary nesting habitat.

  • Conservation Programs:

    • Safe Harbor Program (Private Lands): This program provides private landowners with regulatory assurances in exchange for entering cooperative agreements to maintain or actively sustain RCW habitat above a determined baseline.

    • Translocation: This technique involves moving individuals or groups to suitable habitat to recover small populations and prevent demographic isolation.