ivory-billed woodpecker, common name for the largest of the North American woodpeckers, Campephilus principalis. Once plentiful in Southern hardwood forests, it was believed to be extinct or nearing extinction after 1952. The last known members of this species had been reported from the deepest forests of NW Florida and central Louisiana, and there were no confirmed sightings after 1944 until 2004, when one may have been spotted in an E Arkansas swamp. The Arkansas evidence, however, has been criticized by a number of ornithologists as ambiguous.

A shiny blue-black in color with extensive white markings on its wings and neck, this bird is distinguished by its pure white bill and by a prominent top crest, red in the male and black in the female. A true woodpecker, it has a strong and straight chisellike bill and a long, mobile, hard-tipped, sticky tongue. It measures from 18 to 20 in. (46-51 cm) in length, with short legs and feet ending in large, curved claws. The ivory-bill deposits from three to five glossy white eggs per clutch in an unlined hole, preferably drilled in a cypress tree. Of its reproductive habits little more than this is known.

The decrease in the number of ivory-bills may be largely blamed on the cutting and eventual disappearance of the trees in which they lived. It is not known how many ivory-bills may survive today in the forests of the S United States and in Cuba. Ivory-billed woodpeckers are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Piciformes, family Picidae.

Black-and-white woodpecker (Campephilus principalis) with a flaring crest (red on the male) and a long whitish bill. The largest North American woodpecker, it was thought to be extinct, though there were unconfirmed sightings of the bird in the southern United States in the late 1990s; a small population on Cuba was last seen in the late 1980s. In 2005, however, researchers announced that it had been sighted in eastern Arkansas. The species' decline coincided with the logging of virgin forest, where it subsisted on deadwood insects. A subspecies, the Cuban ivory-billed woodpecker, is also believed to be extinct. A related species, the imperial woodpecker of Mexico, is critically endangered. All these birds appear to have required large trees and isolation from disturbance.

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