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Nature Trivia
By: Renn Tumlison
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Red-cockaded Woodpecker
(Picoides borealis)
Woodpeckers are highly specialized for life in trees. They have sharp-chisel like bills for drilling into wood, two forward-facing toes and two backward facing toes (called zygodactyl feet) for vertical climbing, and stiff tails, which they use as props. Insects are the primary food.
Most species of woodpeckers drill into dead trees, referred to as "snags," and excavate a cavity in them for nesting. Only one species, the Red-cockaded Woodpecker, actually uses living trees as a nesting site. Also unique among woodpeckers, this species lives in colonies.
Mature pines are the tree of choice, particularly ones with red-heart fungus. A fungus-infected tree is easier to excavate because the center of the tree is dead. The living tree is harder to peck through, but the living tree is important in the life history of the bird. Red-cockaded Woodpeckers flick layers of bark off the tree above and below the nest hole.
Numerous smaller holes (resin wells) are drilled through the bark into the living tissue of the tree in those areas, and the tree protects itself by exuding resin.
The resinous pine sap runs down the bark, making a sticky covering to the trunk of the tree. The dripping resin makes the trunk look like a melting white candle, so such a tree is called a "candle tree" (above photo).
The candle tree apparently is a deterrent to predators. Black rat snakes can climb trees (pictured above) and feed on birds in a nest, but the resin makes this more difficult to accomplish. Flying squirrels can also be a problem if they occupy a nest or eat the eggs.
The crow-sized Pileated Woodpecker (pictured in above photo) may enlarge the nest hole for its own use and render it unusable by the Red-cockaded Woodpecker.
Before the heavy colonization by humans and cutting of old growth pine forests, this woodpecker occurred throughout the southeastern United States. Today, the populations are very limited in size and distribution; thus, it has become an endangered species. To aid recovery of the species, forest management now includes the protection of areas where colonies presently occur, and the long-term plan of providing trees that will become suitable for colonies of the birds in the future. Habitat must not have a mid-story (trees of intermediate height). A typical habitat resembles that shown in this photo.
Devices to exclude potential predators (above left photo) and devices to prevent the enlargement of the nest hole by other birds are sometimes placed on den trees. The right photo shows a metal device placed over a hole to prevent other woodpeckers from enlarging the hole. Notice that resin is already beginning to cover the metal.
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Renn Tumlison
Department of Biology
Box 7861
Henderson State University
Arkadelphia, AR 71999
Phone: (870) 230-5152
E-mail: tumlison@hsu.edu
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