Ivory-billed woodpeckers once ranged throughout the southeastern United States, from southern Florida and the Gulf Coast, north to North Carolina and southern Illinois, and west to southeastern Oklahoma and eastern Texas. They were also widespread on the main island of Cuba. Extensive logging of their primary forest habitat greatly reduced their range in both North America and Cuba. They were presumed extinct for a number of years before being rediscovered and videotaped in eastern Arkansas in April of 2004. Currently the Cache River National Wildlife Refuge, in Monroe County, Arkansas is the only place where ivory-billed woodpeckers are known with any certainty to persist. The last confirmed sighting of an ivory-billed woodpecker in Cuba was in 1987. (Jackson, 2002)
Ivory-billed woodpeckers require expansive areas of continuous forest with large trees, and they must have a constant supply of dead or dying trees in which they can excavate cavities and forage for beetle larvae, their staple food. For this reason, they frequent areas of recent disturbance by fire, flood, or hurricane. These large birds prefer forests with relatively open canopies in which they can fly unhindered. Given these requirements, they nest in a diverse array of tree species, including pines, bald cypress, cabbage palmetto, sugarberry, and red maple.
Ivory-billed woodpeckers once inhabited both the upland and lowland forests of the southeastern U.S. However, as the upland pine forests were logged in the 19th century, the birds' habitat shrunk to only include bald cypress swamps and bottomland forests of sweetgum, Nuttall's oak, willow oak, water oak, sugarberry, green ash, and American elm. The Big Woods area of Arkansas is one such bottomland forest.
In Cuba, ivory-billed woodpeckers once occupied both pine and hardwood forests. By the 1950's, they were restricted to a small region in the east characterized by logged pine forest interrupted by occasional hardwood stands along streams. In this area they nested primarily in large dead pines. (Jackson, 2002; Lamb, 1958)
Ivory-billed woodpeckers are the largest woodpeckers in the United States. They measure 48 to 53 cm long, weigh 450 to 570 g, and have wingspans of about 78 cm. Males tend to be slightly larger than females. Ivory-billed woodpeckers have glossy black plumage that contrasts sharply with the white stripes that run from the base of each wing to the sides of the head. The inner primary and secondary wing feathers are also white, and these feathers form a white shield on the back when the wings are folded. Female ivory-billed woodpeckers have a black crests on their heads, males have bright red crests. The irises are a pale lemon-yellow color and the nostrils are covered by tufts of white feathers that keep out debris when the birds are chiseling. The legs and feet are gray, and the toes are long, each bearing a sharp, curved, black claw. Ivory-billed woodpeckers get their name from their distinctive white, chisel-shaped, 7.6 centimeter-long bills, which function as multi-purpose tools for obtaining food, excavating nest cavities, and communicating with conspecifics. (Jackson, 2002)
Ivory-billed woodpeckers are presumed to be monogamous. No information is available on the occurrence of extra-pair copulations or extra-pair fertilizations in this species. (Jackson, 2002)
Because of the rarity of ivory-billed woodpeckers, little data is available on their reproduction. Limited data suggests that ivory-billed woodpeckers begin building nests in late January, lay eggs in February, and that the young fledge in April. Given this timespan, it is likely that these birds follow the same general pattern followed by other North American woodpeckers: nest cavity building takes about 2 weeks, egg laying takes 2 to 5 days, and incubation takes about 2 weeks. Clutch sizes of 1 to 6 eggs have been reported, with an average of 2.7. The young are known to leave the nest about 5 weeks after hatching, and they have an unusually long period of association with their parents that may last a year or more after fledging, although they can forage on their own at three months old. Ivory-billed woodpeckers seem to breed only once per year. Their age at sexual maturity is unknown. (Jackson, 2002)
Ivory-billed woodpeckers begin preparing for the arrival of their offspring at least two weeks before the first egg is laid. They select a dead or partially dead tree with wood that is soft enough for excavation but not so soft that it would provide easy access for predators. They then begin to excavate a cavity, usually just below an overhanging branch or stub (which may keep out rain and/or provide shade). There are conflicting reports on who does the excavating: some say that the male and female take turns and some say that the female does all the work herself. The resulting entrance hole is oblong in shape, about 11 cm wide and 14 cm tall. The cavity itself is about 25 cm wide at its widest point and measures about 54 cm from roof to floor. After the eggs have been laid, the male ivory-billed woodpecker roosts in the a cavity at night with the eggs, and later with the young. During the day the adults take turns brooding their altricial young. Feeding duties are shared more or less equally between males and females. Both feeding and brooding are most intense for the first few days after the eggs hatch and then gradually decline as the nestlings grow older; for example, 30 feedings per day drops to about 15 feedings per day later in the nesting period. Ivory-billed woodpeckers keep their nests fairly clean, but only males have been observed doing the cleaning, removing fecal material and dropping it away from the nest. Parents continue to feed their young for more than two months after the young fledge and the young may stay with their parents for over a year even though they are capable of feeding themselves at three months. (Jackson, 2002)
Ivory-billed woodpeckers are most active in the morning. At night they roost separately in tree cavities that they have excavated and after sunrise they emerge to preen and call their mates. They spend much of their time hitching themselves up tree branches and trunks in typical woodpecker fashion, searching for insects. At about midday there is a lull in activity. Occasionally they hop along on the ground to forage. Flight is graceful and direct; short flights are often accomplished in single swoops and longer flights are powered by steady wingbeats. When ivory-billed woodpeckers must travel a great distance they fly above the canopy. In late afternoon these birds return to their roost trees. They enter their roost cavities around dusk.
Ivory-billed woodpeckers are rarely found in large groups; the most ever observed together was 11 individuals. Small groups of three or four birds have been seen feeding in the same vicinity. Each mated pair has its own home range, but they are not territorial. They are not known to be aggressive toward one another, although they may scold intruding conspecifics. Group size and tolerance of other individuals may be related to habitat quality.
Ivory-billed woodpeckers seem to be sedentary, but some have suggested that they are nomadic, moving around to take advantage of dead trees left over from recent disturbance. (Jackson, 2002)
Home ranges are quite large; individuals in the U.S. have been observed traveling up to 4 km away from their nests. Taking this distance as the radius of a circle, the total home range size is about 50 square kilometers. Lamb (1958) calculated an even larger home range size for ivory-billed woodpeckers in Cuba, about 65 square kilometers. The fact that these woodpeckers have such large home ranges helps to explain why they require such large tracts of continuous forest in order to survive. (Jackson, 2002; Lamb, 1958)
Ivory-billed woodpeckers, like most birds, perceive their environment through visual, auditory, tactile, and chemical means. The relative acuteness of ivory-billed woodpeckers' senses is unknown, but presumably they have good vision and hearing as they use auditory and visual signals to communicate with one another. They have a distinctive call note, "kent", which is often described as sounding similar to a note from a tin trumpet or a New Year's Eve party horn. When pairs are together they utter somewhat softer call notes, and when more than two are together they engage in soft chatter or sometimes a chorus of long, upslurred notes. Family members trade call notes back and forth throughout the day as they forage, growing quiet towards evening. Ivory-billed woodpeckers also communicate by drumming their heavy bills on tree surfaces. Their distinctive drum sound is a double rap, the first rap slightly louder than the second, so that it sounds like the second is an echo of the first. Finally, the bright red crest of a male ivory-billed woodpecker sends a clear visual signal, and no doubt serves a communicatory function, but its exact purpose has not been studied. (Jackson, 2002)
Ivory-billed woodpeckers feed on large beetle larvae, which they find by stripping away the bark of dead or dying trees. Occasionally, they forage for insects on the ground in recently burned areas or in fallen logs. Insects consumed belong to the families Cerambycidae, Buprestidae, Elateridae, Scolytidae, Melasidae, and also include arboreal termites (Isoptera). However, insects only make up about half the diet; in addition, ivory-billed woodpeckers eat berries, nuts and seeds, including cherries, southern magnolia fruits and seeds, pecan nuts, hickory nuts, poison ivy seeds, grapes, persimmons, hackberries, and possibly acorns. (Jackson, 2002)
No one has ever recorded predation on ivory-billed woodpeckers, except for that by humans. Potential predators include raccoons, rat snakes, great horned owls, barred owls, Cuban crows, American crows, red-shouldered hawks, Cooper's hawks, and Stygian owls. There is a report of a pair of ivory-billed woodpeckers chasing a Cooper's hawk away from their nest while scolding it, and another report of a female ivory-billed woodpecker giving a warning call and flying closer to her fledgling when a red-shouldered hawk appeared in the area. There are also reports of ivory-billed woodpeckers rapidly switching to the other side of trees when birds of prey materialized nearby. (Jackson, 2002)
Thanks to their chisel-like bills, ivory-billed woodpeckers are potential ecosystem engineers. The tree cavities they excavate are probably used by an array of other species once the woodpeckers leave. These species might include wood ducks, eastern bluebirds, opossums, gray squirrels, and honeybees.
Because they share many similarities, some have suggested that ivory-billed woodpeckers compete with pileated woodpeckers for food and prime cavity sites. Competition between the two species may have intensified after forests were logged, with pileated woodpeckers, which adapt much more readily to human disturbance, being more successful. However, interactions between ivory-billed woodpeckers and other woodpecker species have never been directly studied.
Ivory-billed woodpeckers are predators of insects, but it is doubtful they have a huge impact on insect populations as their numbers are so low. Because they eat fruits and seeds, it is possible that ivory-billed woodpeckers disperse seeds.
Recently, researchers discovered a new species of feather mite on museum skins of ivory-billed woodpeckers. They named the new mite Pterotrogus principalis. This mite is the only known parasite of ivory-billed woodpeckers. (Jackson, 2002; Mironov, et al., 2005)
Ivory-billed woodpeckers have had economic importance to humans for centuries. Native Americans collected them for their bills, which symbolized successful warfare. American colonists traded with Native Americans for the bills, which they saw as a curiosity. Later, the heads of ivory-billed woodpeckers were sold as souvenirs and the bills were marketed as real ivory. In the late 19th century, collecting natural items became popular, and ornithologists paid dearly--$40 to $50 per bird--to add ivory-billed woodpeckers to their collections. In Cuba, humans sometimes ate ivory-billed woodpeckers or killed them for sport. Of course, the economic importance of ivory-billed woodpeckers waned as their numbers dwindled, but now once again they are having an impact. The rediscovery of ivory-billed woodpeckers has received much popular press, and ornithologists and birdwatchers are already flocking to Arkansas in the hopes of glimpsing the rare bird. The Cache River National Wildlife Refuge happens to be situated in one of the poorest areas of the nation, but locals are hoping that the rediscovery of ivory-billed woodpeckers will give their economy a jump start. No doubt there will at least be a demand for lodging to accomodate the influx of ecotourists, and the surrounding towns may actually see the opening of new businesses, after experiencing a steady population decline stretching back to the 1950s. (Associated Press, 2005; Jackson, 2002)
The only known negative impact of ivory-billed woodpeckers on humans results from their protected status: 5,000 acres of land surrounding the locality where ivory-billed woodpeckers were rediscovered have been closed to hunting and fishing, and locals fear that more will follow. Currently, hunting and fishing drive the local economy. However, it is likely that the economic benefits of tourism resulting from visitors to the area in search of ivory-billed woodpeckers will more than make up for this potential loss. (Associated Press, 2005)
United States: Ivory-billed woodpecker populations have been in decline since the early 19th century, and perhaps even earlier. Their requirement for vast tracts of undisturbed forest made them vulnerable to intense logging efforts in their native range. By the 1930's it was estimated that fewer than 25 ivory-billed woodpeckers remained in the United States. A substantial fraction of those were living in the 81,000-acre Singer Tract of northeastern Louisiana. Though efforts were made to preserve this valuable bit of remaining habitat, which was the largest remaining piece of virgin forest in the southern United States, the Singer Tract was logged by the late 1940s and with it went much hope for the continued existence of ivory-billed woodpeckers. However, unconfirmed sightings were occasionally noted throughout the years from Missouri, Florida, Georgia, South Carolina, Texas, and Louisiana. Reports of their existence in Florida prompted the formation of the Chipola River Wildlife Sanctuary in 1950, but there were no further sightings and the sanctuary was discontinued two years later. In 2002, after a reported ivory-bill sighting in the area, researchers conducted a two month long search in the Pearl River Swamp of Louisiana, but found no conclusive evidence of their persistence in this area. Finally, in February of 2004, a kayaker saw an ivory-billed woodpecker in the Cache River National Wildlife refuge in Monroe County, Arkansas. This sighting was confirmed when researchers were able to videotape the bird in April of 2004, the first confirmed ivory-billed woodpecker sighting since 1944. After gathering additional evidence for a year, including sound recordings, the researchers published their findings in April 2005. The federal government has pledged $10 million towards the protection of ivory-billed woodpeckers, and another $10 million has been pledged by private sector groups and individuals. A recovery plan that will protect the birds' critical habitat is currently in the works. In the meantime, managers of the wildlife refuge have restricted access to 5,000 acres of forest in the area where ivory-billed woodpeckers were spotted.
Cuba: Ivory-billed woodpecker populations declined sharply in the late 19th century, when acres of old-growth forest were cleared to make way for sugar plantations. Later harvesting of forests for timber exacerbated the decline. By the 1950s, ivory-billed woodpeckers were restricted to a remote area in the eastern part of the country, in what was then the Oriente Province (now Santiago de Cuba). Management plans were adopted that involved educating the public about the birds' plight and setting aside preserves protected by wardens. Ivory-billed woodpeckers managed to persist in eastern Cuba until at least 1987. However, the last unconfirmed sighting occurred in northeastern Cuba in 1991, and ivory-billed woodpeckers are now presumed extirpated in Cuba.
The IUCN currently lists ivory-billed woodpeckers as critically endangered, after having listing them as threatened in 1988, extinct in 1994, and critically endangered in 2000. The U.S. Fish and Wildlife Service lists them as endangered. (BirdLife International, 2004; Cornell Lab of Ornithology, 2005; Fitzpatrick, et al., Published online April 28, 2005; Garrido, 1985; Jackson, 2002; Lamb, 1958; U.S. Department of the Interior, et al., 2005)
There are two recognized supspecies of ivory-billed woodpecker: Campephilus principalis principalis, the U.S. subspecies, and Campephilus principalis bairdii, the Cuban subspecies, which is now presumed extinct. The Cuban subspecies is distingued by its smaller size, white stripe that extends further forward on the head, and smaller nasal tufts.
It is unknown how ivory-billed woodpeckers arrived in Cuba. It is possible that they arrived on their own during the Pleistocene glaciation, when sea levels were lower. Some have suggested that they might have been introduced through human actions.
The fossil record of ivory-billed woodpeckers is sparse, but their bones have been excavated at archaeological sites as far north as Illinois and Ohio, emphasizing how important these birds were as items of trade for Native Americans. (Jackson, 2002)
Tanya Dewey (editor), Animal Diversity Web.
Allison Poor (author), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the southern part of the New World. In other words, Central and South America.
uses sound to communicate
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
A substance that provides both nutrients and energy to a living thing.
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
Having one mate at a time.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
generally wanders from place to place, usually within a well-defined range.
an animal that mainly eats all kinds of things, including plants and animals
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
associates with others of its species; forms social groups.
a wetland area that may be permanently or intermittently covered in water, often dominated by woody vegetation.
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
uses sight to communicate
Associated Press, 2005. "Poor towns hope to feather nests" (On-line). Accessed May 10, 2005 at http://www.cnn.com/2005/TRAVEL/05/05/woodpecker.ap/index.html.
BirdLife International, 2004. "Campephilus principalis" (On-line). 2004 IUCN Red List of Threatened Species. Accessed May 09, 2005 at www.redlist.org.
Cornell Lab of Ornithology, 2005. "Rediscovering the ivory-billed woodpecker" (On-line). Accessed May 11, 2005 at http://birds.cornell.edu/ivory/.
Fitzpatrick, J., M. Lammertink, M. Luneau Jr., T. Gallagher, B. Harrison, G. Sparling, K. Rosenberg, R. Rohrbaugh, E. Swarthout, P. Wrege, S. Swarthout, M. Dantzker, R. Charif, T. Barksdale, J. Remsen Jr., S. Simon, D. Zollner. Published online April 28, 2005. Ivory-billed woodpecker (Campephilus principalis) persists in continental North America. Science, 10.1126/science.1114103 (Science Express). Accessed May 09, 2005 at http://www.sciencemag.org/cgi/rapidpdf/1114103v1.pdf.
Garrido, O. 1985. Cuban endangered birds. Pp. 992-999 in P Buckley, M Foster, E Morton, R Ridgely, F Buckley, eds. Neotropical Ornithology, Vol. Ecological Monographs, no. 36. Washington, D.C.: The American Ornithologists' Union.
Jackson, J. 2002. "Ivory-billed Woodpecker (Campephilus principalis)" (On-line). The Birds of North America Online. Accessed May 09, 2005 at http://bna.birds.cornell.edu/BNA/account/Ivory-billed_Woodpecker/.
Lamb, G. 1958. Excerpts from a report on the ivory-billed woodpecker (Campephilus principalis bairdii) in Cuba. Bulletin of the International Committee for Bird Preservation, 7: 139-144.
Mironov, S., J. Dabert, R. Ehrnsberger. 2005. A new species of the feather mite genus Pterotrogus Gaud (Analgoidea: Pteronyssidae) from the ivory-billed woodpecker Campephilus principalis L. (Aves: Piciformes). Annals of the Entomological Society of America, 98(1): 13-17.
U.S. Department of the Interior, , U.S. Fish and Wildlife Service, U. S. Department of Agriculture. 2005. "Once-thought extinct ivory-billed woodpecker rediscovered in Arkansas" (On-line). U. S. Fish and Wildlife Service. Accessed May 11, 2005 at http://www.fws.gov/southeast/news/2005/r05-029.html.