Ecology and Behavior

The Life of the Ivory-bill

The Ivory-billed Woodpecker (Campephilus principalis) was historically found in the old-growth forests of the southeastern United States and Cuba, where it fed on insects, primarily beetle larvae, and sometimes fruits and nuts. To get to the beetle larvae, the birds strip the still-tight bark from recently dead trees. To do this, they use their enormous ivory-colored bill (which is not made of ivory but rather, bone covered with keratin). Because the ivory-bill has a specialized diet of beetle larvae, it requires an extensive habitat of mature forests with many recently dead, but still standing, trees where the beetle larvae live.

Ivory-bills don't have the undulating flight that is characteristic of many other woodpeckers. Rather, their flight is strong and direct. When traveling any distance, they typically fly above the trees to avoid navigating through branches.

Our knowledge about ivory-bills is limited because there have been so few in-depth studies of the species. Some ornithologists believe that this bird is nomadic, continually searching for suitable habitat. In the 1930s, Cornell University researcher James T. Tanner estimated that each pair of ivory-bills required a territory at least 6 square miles in size. Ornithologists speculate that they may live as long as 20 to 30 years.

The call of the ivory-bill is a nasal-sounding "kent," often described as sounding similar to the toot of a tin horn. Ivory-bills are also known for the unique double-knock they make when striking a tree with their beaks. Ornithologists believe this double-knock is used to announce its presence. Most woodpeckers in the ivory-bill's genus (Campephilus) make a similar double-knock, but all the other species live in Latin America.

In 1937, Cornell Laboratory of Ornithology researchers Arthur Allen and Peter Paul Kellogg watched as a pair of Ivory-billed Woodpeckers flew to a dead pine, perched near one another, and preened. The male and female clasped bills, apparently in a courtship display. Ivory-bills excavate trees for nesting cavities and roosts. They begin breeding in January, laying an average of three eggs per clutch. Both parents care for the young. Ivory-billed Woodpeckers fledge at about five weeks of age and may remain dependent on their parents for a year or more.

For detailed and authoritative information about the life history of the Ivory-billed Woodpecker, please visit the free demo profile in The Birds of North America Online.