Red-cockaded Woodpecker (Picoides borealis) -- No more than about 12,000 of these endangered woodpeckers are left. Gone is more than 99% of its historic habitat -- mature pine forest, primarily in southeastern North America. The only woodpecker to excavate its nest hole in living trees, this species requires old pine trees, old enough to have acquired the core-softening fungal ailment called red-heart disease. Virtually all remaining suitable trees are on state and federal lands. They are cooperative breeders, with year-old males remaining with parents to care for the next year's brood. This bird, photographed at Big Branch NWR, on 15 May 2005, is at the nest hole, having just delivered a meal to begging nestlings. Visible all around it are the sap wells this species drills to keep resin flowing as a deterrent to rat snakes and other predators.