Ivory-billed Woodpeckers used extensive stands of large trees and often foraged in areas where many trees had been recently killed by flooding, fire, and other disturbances. They originally occurred in upland pine forests, but by 1891 they nested mainly in bald cypress swamps and foraged in the drier margins where the swamps met upland pine forests. In Louisiana, where Jim Tanner made his classic study of Ivory-bills during the 1930s, he found them in essentially undisturbed areas of mature forest that included both dry uplands and flooded swamps. The main tree species in this area were sweetgum, Nuttall’s oak, green ash, American elm, willow and water oaks, and sugarberry (hackberry). Tanner estimated that one pair of Ivory-billed Woodpeckers occupied about 6 square miles of forest. The subspecies in Cuba was also affected by logging and by the mid-1800s was restricted to pine uplands.Back to top
Ivory-billed Woodpeckers ate mostly large beetle larvae of the longhorn, jewel, and click beetle families. To a lesser extent they also ate the much smaller larvae of the bark beetle family, including the southern pine beetle. These beetle species can reach large numbers in areas where fire, floods, and other disturbances create stands of dead trees—a feature that Ivory-bills sought out. They typically used their large bills to strip the bark from dead trees and fallen logs, or less frequently made deep excavations into the wood as Pileated Woodpeckers do. They also ate fruits and nuts including hickory, pecan, magnolia, poison ivy, grapes, persimmons, hackberries, and possibly acorns.Back to top
Ivory-bills excavated nests in dead trees or in dead sections of living trees, typically just below a broken branch, both for protection from rain and because the wood there has often been softened by fungi and rot. They nested in baldcypress, pines, red maple, Nuttall's and overcup oaks, bay, elm, sweetgum, tupelo, hackberry, and possibly cabbage palm. Nests were between 15 and 70 feet above the ground.
Audubon reported that both sexes excavated the nest hole. They excavated an oval nest 4–5 inches wide and 5–6 inches tall. Inside, the hole could be as deep as 2 feet. The birds stripped away bark from below the nest entrance. The birds typically built a different nest hole each year.
|Clutch Size:||1-5 eggs|
|Condition at Hatching:||Naked and helpless.|
Audubon described the Ivory-bill’s flight as “graceful in the extreme,” with long, swooping glides between trees. Tanner, in his 1930s studies, described them flying with steady wingbeats in a strong, direct path. The birds often flew above the treetops when traveling longer distances. Ivory-billed Woodpeckers may have been fairly social, with reports of as many as 11 individuals seen at one time and 4 foraging in the same tree. The birds were probably monogamous and maintained their pair bonds year-round. In one report of a courtship display, a male perched near a female, the pair preened, and then the birds held each other’s bills briefly.Back to top
The Ivory-billed Woodpecker is probably extinct. Partners in Flight rates the species 18 out of 20 on the Continental Concern Score and places it on the Red Watch List. Ivory-billed Woodpecker is also listed as Critically Endangered on the IUCN Red List, and federally endangered by the U.S. Fish and Wildlife Service. Destruction of the woodpecker's mature or old-growth forest habitat caused populations to decline, and by the 1880s the species was rare. Forest destruction accelerated during the World War I and II war efforts, destroying much of its habitat. Although the species was thought to be extinct, it was rediscovered in Arkansas in 2004. However, extensive searches from 2006–2010 did not produce any definitive evidence of a surviving population.Back to top
Fitzpatrick, J. W., M. Lammertink, M. D. Luneau Jr., T. W. Gallagher, B. R. Harrison, G. M. Sparling, K. V Rosenberg, R. W. Rohrbaugh, E. C. H. Swarthout, P. H. Wrege, S. Barker Swarthout, M. S. Dantzker, R. A. Charif, T. R. Barksdale, J. V. Remsen Jr., S. D. Simon, and D. Zollner. (2005). Ivory-billed Woodpecker (Campephilus principalis) persists in continental North America. Science 308:1460–1462.
IUCN. (2017). The IUCN Red List of Threatened Species. Version 2016-3 2016 [cited 17 January 2017]. Available from www.iucnredlist.org.
Jackson, Jerome A. (2002). Ivory-billed Woodpecker (Campephilus principalis), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Partners in Flight (2017). Avian Conservation Assessment Database. 2017.
U.S. Fish and Wildlife Service, ECOS-Environmental Conservation Online System. (2018). Ivory-billed Woodpecker (Campephilus principalis).