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Red-Cockaded
Woodpecker (Picoides borealis) In the vast stands
of centuries-old pines that once stretched from the Atlantic Coast to
the forests of eastern Oklahoma, the red-cockaded woodpecker (Picoides
borealis) once thrived. In the mid-1800s, John J. Audubon described
the red-cockaded woodpecker as abundant in Southern pine forests. But
the farming practices of the European settlers and the progressive changes
in timber management combined to drive this territorial, non-migratory
bird nearly to extinction. Unlike other woodpeckers, the red-cockaded
roosts in cavities in live pines. It needs 80 to 120-year-old with long-leaf
pines and loblolly pines averaging 70 to 100 years old for its cavities,
and extensive pine and pine-hardwood forests to meet its foraging requirements.
Henry (1989) defined RCW foraging habitat as "pine and pine-hardwood
stands 30 years of age or older, contiguous to and within 0.5 mile of
the center of the colony." Within this 0.5 mile radius, 8,490 ft.
squared pine basal area (cross-sectional area of a tree measured at
4.5 feet above the ground, and usually summed on an acre basis) and
6,350 pine stems 10 inches or larger in diameter at breast height (dbh)
(diameter of a tree measured at 4.5 feet above the ground) are considered
foraging habitat requirements. The red-cockaded woodpecker is about the size of the common cardinal or robin, approximately 7 inches long, with a wingspan of about 15 inches (35 to 38 cm). Its back is barred with black and white horizontal stripes. The RCW's most distinguishing feature is a black cap and nape that encircle large white cheek patches. Rarely visible, except perhaps during the breeding season and when defending its territory, the male has a namesake small red streak -- called a cockade -- on each side of its black cap. These small woodpeckers are unique in two ways. First, it is the only woodpecker that excavates its nesting and roosting cavities in living trees: preferably old-growth longleaf or loblolly pines. Second, the red-cockaded woodpecker lives within a tight-knit extended family community of breeding birds and helper birds. In order to survive and prosper, the RCW requires open, parklike forested landscapes of longleaf pine and relatively large home ranges of up to 500 acres, which foster group interactions and population expansion. Mature longleaf pine trees are a necessity because the older trees often fall prey to a fungus called red-heart disease. This fungus softens the core of the tree, making it easier for the woodpecker to create its nesting and roosting cavities. The RCW feeds primarily
on wood-boring insects, beetles, wood roaches, ants, centipedes, caterpillars,
and spiders; occasionally the adults will be observed feeding on blueberry,
sweet bay berries, and poison ivy. The southern pine ecosystems, once contiguous across large areas and kept open with recurring fire, provided ideal conditions for a nearly continuous distribution of red-cockaded woodpeckers throughout the South. The red-cockaded woodpecker's range extended from Florida to New Jersey and Maryland, as far west as Texas and Oklahoma, and inland to Missouri, Kentucky, and Tennessee. The range included the entire longleaf pine ecosystem, but the birds also inhabited open shortleaf, loblolly, and Virginia pine forests, especially in the Ozark-Ouachita Highlands and the southern tip of the Appalachian Highlands Today those old
southern pine forests are gone, and fewer trees are permitted to mature,
creating a scarcity of pines suitable for woodpecker habitat. Approximately
one percent of the red-cockaded woodpecker's historical habitat remains.
Logging has claimed many of the ancient trees, and fire suppression
has allowed a hardwood understory to encroach on the RCW's habitat,
making it undesirable for the birds. The majority of the remaining woodpeckers
live in clusters (groups of cavity trees) along the eastern seaboard
from Florida to Virginia, and west to southeast Oklahoma and eastern
Texas. A family group of red-cockaded woodpeckers will create a collection of cavity trees, called a "cluster." Each bird in the group maintains its own cavity tree. Typically, each cluster consists of two to as many as fifteen cavity trees, and may occupy a region from 5 to 10 acres or even larger. Each group normally occupies and defends only one cluster. Red-cockaded family
groups defend territories that cover an average of 200 acres, though
some group territories are as small as 60 acres, and others as large
as 600 acres have been observed. The size of a given territory is related
to both habitat suitability and population density. This arrangement
promotes continuity among family groups: Should the patriarch die, one
of his offspring stands ready to inherit the family territory. RCWs often have
the same mate for several years. The nesting season lasts from April
through June. The group helps to construct a nest made of wood chips
in the breeding male's roost cavity. The breeding female lays usually
two to four small white eggs in this nest. Then the group helpers take
over and incubate the eggs for 10 to 12 days. Once hatched, the nestlings
remain in the nest cavity for about 26 days. Rearing the fledglings
is a shared responsibility of the group. However, a single pair of RCWs
can breed successfully without a group of helpers. After several weeks,
the fledges are largely independent. Juvenile females generally leave
the group in the fall or winter, before the next breeding season, in
search of solitary male groups. Some of the young males will leave at
the same time in search of their own territory.
Once a cavity is completed, the RCW pecks numerous small holes -- called resin wells -- around the tree under the cavity. This causes large quantities of sap to run down the tree in rivulets, coating the tree and giving it a candle-like appearance. The sap theoretically deters rat snakes and other predators from reaching the cavity. The woodpeckers spend a significant amount of time and energy each day maintaining the flow of the resin wells. If the tree should die, or the damage from maintaining the wells becomes so great that the sap stops flowing, the woodpeckers will eventually abandon the cavity tree, potentially to other forest dwellers. A number of other birds and small mammals use the cavities excavated by red-cockaded woodpeckers. Chickadees, bluebirds, and titmice will happily take up housekeeping in an RCW cavity. Several other woodpecker species, including the downy, hairy, and red-bellied woodpecker, may take over a RCW cavity, sometimes enlarging the hole enough to allow screech owls, wood ducks, fox squirrels and other mammals to later move in. Flying squirrels, several species of reptiles and amphibians, and insects, primarily bees and wasps, also will use RCW cavities. This makes the RCW an important part of the forest ecosystem, providing homes for many animals which would not normally choose to create a home in a living pine. However, cavity competition is a major concern for those trying to revive this species. Sometimes, small mammals such as southern flying squirrel (Glaucomys volans) or larger woodpeckers don't wait until an RCW cavity is abandoned before moving in. And, once a red-bellied, red-headed, or pileated woodpecker enlarges the cavity entrance, it is rendered unsuitable for the red-cockaded woodpecker. It takes a RCW one to three years to excavate a tree cavity. The disappearance of the red-cockaded woodpecker coincided with the loss of the longleaf pine ecosystem. As settlers and the early timber industry cut the forests, birds were isolated in tracts where trees deemed unmarketable were left standing. Aerial and ground photographs from the 1930s show scattered medium-to-large trees left in many stands. These culled trees at least for a time provided nesting and foraging habitat for the birds. But the threat of a disappearing habitat continued. Beginning in the 1950s, the forest structure and composition changed dramatically, especially on lands managed for forest products. Accepted techniques such as clear cutting, short timber rotations, conversion of longleaf stands to other faster growing pine species, and "clean" forestry practices (removal of cavity, diseased, or defective trees) eliminated much of the remaining RCW habitat. At the same time, aggressive fire suppression promoted the growth of a hardwood midstory in pine forests, choking out the open stands of longleaf pine with wiregrass ground cover sought by the RCW. The RCW has several natural predators that thrive in the cover of a midstory habitat, including the black rat snake. Agile tree climbers, rat snakes eat woodpecker eggs and nestlings. However, the red-cockaded woodpecker has an effective means of defense. It chips small holes (called resin wells) in the bark of the cavity tree, above and below the cavity. Sap from these holes oozes down the trunk of the tree. The sap adheres to the scales of the rat snake; even tiny amounts of resin apparently inhibit the movement of the scales, preventing the snake from climbing higher. The loss of open
pine habitat caused dramatic declines in the RCWs population; it was
listed as an endangered species in 1970 (Federal Register 35:16047). The largest populations of RCWs today are found within the historical longleaf pine ecosystem. Within the longleaf range, there are 4 populations with more than 200 groups, and 11 populations with more than 100 groups. All but one of these large population clusters are located on federal lands. Carolina Sandhills Refuge supports the largest population of RCWs on Fish and Wildlife Service land, with 140 clusters. The remaining longleaf pine-associated populations are small and isolated, continually threatened by predators, cavity competition, and the destruction of their habitat. The Red-cockaded Woodpecker Recovery Plan (USFWS 1985) specifies that recovery will be achieved when 15 viable populations are established and protected by adequate habitat management programs. Each recovery population will likely require 400 breeding pairs -- or 500 active clusters, as some clusters are occupied by single birds or contain nonbreeding groups -- to ensure a sustained RCW population. Evidence indicates
that red-cockaded woodpecker populations can expand on their own, but
with some management assistance their expansion can occur to viable
levels more quickly. The Carolina Sandhills Refuge uses a variety of
approaches aimed at ensuring the survival of the red-cockaded woodpecker.
These include: According to the Refuge staff biologists, these ecosystem management plans promote practices that reduce landscape fragmentation, retain suitable numbers of potential cavity trees well distributed throughout the landscape, and restore the original forest floor cover. The use of growing-season fires to control hardwoods creates the required open forest condition to support RCW populations. In another management program at the Carolina Sandhills Refuge, juvenile birds are translocated from stable larger populations into small ones; some young birds are also sent to other protected sites working with the red-cockaded woodpecker. Not only is there now government housing for the red cockaded woodpeckers, but also a government dating game! If an unpaired male is noted in a territory without females, scientists may translocate a female from elsewhere to try to encourage mating between the two. The U.S. Fish and Wildlife Service believes that during the past 5 years, several RCW populations in the southern states have stabilized or increased as a result of integrating available technology with the RCW's ecological requirements. Artificial cavities are an important element of this success. But then again, it is difficult for the Service to know for sure since the RCW has faced unforeseen circumstances that have affected many family groups and habitat from wildfires, floods and hurricanes. In 1989, this woodpecker was dealt a blow from Mother Nature as Hurricane Hugo destroyed vast numbers of the trees that Red-cockaded Woodpeckers use to nest. The U.S. Forest Service, the U.S. Fish and Wildlife Service, and the U.S. Army each have management and recovery guidelines for their respective federal properties where the RCW will be recovered. The issues surrounding protection and management of red-cockaded woodpeckers on private lands are addressed through a private lands strategy, including a procedural manual for private landowners, Statewide Habitat Conservation Plans, and Memorandums of Agreement with industrial forest landowners. (See the Safe Harbors page on the Southern Pines Ecosystems Project website and the No Surprises page.) To fully restore the red cockaded woodpecker to the South, large-scale habitat restoration is needed on private lands. The Forest Service at the Savannah River Site is helping with an ongoing cooperative effort with South Carolina. They have developed a longleaf pine seed orchard in which genetically superior longleaf seeds will be available for Federal, State and private lands to help restore the red cockaded woodpecker. However, there is growing concern among scientists and environmentalists regarding genetically modified trees and plants. More scientific research is needed before anyone, including government agencies, can be 100% sure that genetically modified trees are safe in the long-term for the RCW and other species, including humans. Currently, what we do know for sure is that no more habitat should be destroyed through logging and other human related development of lands.
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