This species historically inhabited the southeastern U.S. and parts of Cuba's main island, and these populations are considered separate races, or possibly even different species, according to a recent analysis. They never occurred in high densities. The Ivory-bill became increasingly restricted to smaller and smaller areas as habitat was destroyed throughout the 19th and 20th centuries. In 1908, it probably occurred only in Florida and Louisiana. The last confirmed Cuban sighting was in 1988 in the Sierra de Moa Mountains of eastern Cuba. The next-to-last known population in the US disappeared in 1948 when the Singer Tract in Louisiana was cleared for soybean production. In 2004 and 2005, single birds were reported in Arkansas. One bird was videotaped, and seven or so people reported observations of an Ivory-bill. However, the identity of the bird in the videotape has been questioned. Additionally, sound recordings of birds nearby are far enough apart to be separate individuals. However, these recordings cannot be definitively assigned to the Ivory-billed Woodpecker. As of 2007, the search continues in Arkansas, Florida, and in other parts of the bird's range.
The Ivory-bill prefers thick hardwood and cypress swamps and pine forests with lots of dead trees for nesting and feeding. In an extensive forest, typical trees include American elm, bald cypress, cabbage palmetto, green ash, red maple, sugarberry, sweet gum, and various pines. In Cuba, it inhabits both tropical hardwood and mixed lowland forests and montane pine forests. Areas that recently experienced forest fires are also inhabited by Ivory-bills because of the large number of dead trees. An estimated 16 square kilometers of mature forest is needed to support one pair.
Dead trees provide not only nesting cavities, but also food. The Ivory-bill removes bark by chipping it with its bill in repeated blows. The Ivory-bill leaves pits in trees similar to those created by Pileated Woodpeckers, but these lead to beetle larvae tunnels not carpenter ants. In parts of its range, this woodpecker forages on tree species like sweet gum and Nuttal's oak, more often than on others. Through these foraging methods it collects wood-boring insect larvae (long-horned and engraver beetles). It also consumes seeds (southern magnolia and poison ivy), berries, nuts (pecan and hickory), and fruits (grape, persimmon, and wild cherry).
This species breeds from January to April in the U.S. and from March to June in Cuba. In early January, nest holes are excavated in large dead trees or the soft parts of living trees. In Cuba, palm trees are used occasionally. 25-50 feet above the ground, holes are usually excavated under a branch or a branch stub, probably as a weather guard. Pairs are probably monogamous, and the courtship may include perching close together and then holding each other's bill. For an unknown period of time, a clutch of 3 or 4 white eggs is incubated by both parents, with males assuming sole responsibility at night. The hatchlings have not been described. Each adult feeds the young as many as 30 times every day, but that rate is cut in half as the nestlings age. Juvenile Ivory-billed Woodpeckers remain dependent for up to a year.
The Ivory-billed Woodpecker does not migrate, but will wander over vast areas in search of dead and dying trees.