The Ivory-billed woodpecker is a very rare member of the woodpecker family and is one of the largest woodpeckers in the world. The last universally accepted sighting of an American ivory-billed woodpecker occurred in Louisiana in 1944. The plumage of these birds is predominated a shiny black-purple. There are white lines extending from the cheeks down the neck meeting on the back. Ivory-bills have a prominent crest, although in juveniles it is ragged. Like all woodpeckers, they have a strong and straight bill and a long, mobile, hard-tipped, barbed tongue. In adults, the bill is ivory in color, while it is chalky white in juveniles.
Ivory-billed woodpeckers are found in the Southeastern United States and Cuba. They prefer thick hardwood swamps and pine forests, with large numbers of dead and decaying trees.
Ivory-billed woodpeckers are diurnal birds, spending their nights in individual roost holes, which are often reused. The birds typically leave their roost holes around dawn, feeding and engaging in other activities in the early morning. They are generally inactive during the mid-day and resume feeding activities in the late afternoon before returning to the roosts around dusk. To hunt some prey items such as woodboring grubs, Ivory-bills use their enormous bill to hammer, wedge, and peel the bark off dead trees to access their tunnels. For these grubs, Ivory-bills have no real competitors; no other species present in their range are able to remove tightly bound bark as Ivory-billed woodpeckers do. These birds need about 25 km2 (9.7 sq mi) per pair to find enough food to feed their young and themselves. Ivory-billed woodpeckers are social and not territorial; they don't protect their territories from other Ivory-bills when encountering one another. Indeed, in many instances, Ivory-billed woodpeckers may gather in groups of 4 or 5 birds feeding together on a single tree, and as many as 11 have been observed feeding in the same location. Although not migratory, Ivory-billed woodpeckers may relocate from time to time to areas where disasters such as fires or floods have created large amounts of dead wood, and subsequently large numbers of beetle larva upon which they prefer to feed. Ivory-bills communicate with four fairly distinct calls. The most common, a 'kent' or' hant', sounds like a toy trumpet often repeated in a series. When the birds are disturbed, the pitch of the 'kent' note rises, it is repeated more frequently, and it is often doubled. A conversational call is given between individuals at the nest and has been described as 'kent-kent-kent'. The drum of Ivory-billed woodpeckers is a single or double rap.
Ivory-billed woodpeckers are omnivores. Their preferred food is beetle larvae but they also eat fruit of the southern magnolia, pecans, acorns, hickory nuts, and poison ivy seeds. They have also been observed to feed on wild grapes, persimmons, and hackberries.
Ivory-billed woodpeckers are monogamous and are thought to mate for life. Pairs are also known to travel together. They breed between January and May. Both parents work together to excavate a cavity in a tree about 15-70 feet (4.6-21.3 m) from the ground before they have their young. Eggs are typically laid in April or May. The clutch consists of 3 to 6 glossy, china-white eggs. Parents incubate the eggs for 3 to 5 weeks; the male incubates overnight, and the two birds typically exchanging places every two hours during the day, with one foraging and one incubating. Once the young hatch, both parents forage to bring food to them. The chicks learn to fly about 7 to 8 weeks after hatching and their parents continue feeding them for another 2 months. The family eventually splits up in late fall or early winter.
Heavy logging activity exacerbated by hunting by collectors devastated the population of Ivory-billed woodpeckers in the late 19th century. They were generally considered extremely rare, and some ornithologists believed them extinct by the 1920s. These factors most probably threaten the remaining population of the species at present.
According to the IUCN Red List, the total Ivory-billed woodpecker population size is fewer than 50 individuals and mature individuals. Currently, this species is classified as Critically Endangered (CR) on the IUCN Red List and its numbers today are decreasing.