The imperial woodpecker (Campephilus imperialis) is a woodpecker species endemic to Mexico. If it is not extinct, it is the world's largest woodpecker species, at long. Researchers have discovered that the imperial woodpecker has slow climbing strides and a fast wing-flap rate compared with other woodpeckers. Owing to its close taxonomic relationship, and its similarity in appearance, to the ivory-billed woodpecker (C. principalis), it is sometimes called the Mexican ivory-billed woodpecker, but this name is also used for the extant pale-billed woodpecker (C. guatemalensis). The large and conspicuous bird has long been known to the native inhabitants of Mexico and was called in Nahuatl, by the Tepehuán and by the Tarahumara.
Description and ecology
The imperial woodpecker's typical size ranges from . The male imperial woodpecker has a red-sided crest, centered black, but otherwise mostly black, with large white wing-patches, thin white “braces” on its mantle and a huge ivory-colored bill. They are all black except for the inner primaries, which are white-tipped, the white secondaries and a white scapular stripe which, unlike the ivory-billed woodpecker, does not extend onto the neck. The female is similar, but her crest is all black and (unlike the female ivory-bill) recurved at the top, lacking any red. Much larger than any other sympatric woodpecker, it is the only woodpecker in the area with solid black underparts. Its voice is reportedly toy trumpet-like. The bird was once widespread and, until the early 1950s, not uncommon throughout the Sierra Madre Occidental of Mexico, from western Sonora and Chihuahua southwards to Jalisco and Michoacán. It is likely that, in the past, the woodpecker's range followed the Sierra Madre north into Arizona, but by the time it was scientifically described in the 19th century, it was already confined to Mexico. It has been suggested that it might occur in Arizona, and there is also a hypothetical record of it in 1958 in Big Bend National Park, Texas, however this is not mentioned in Oberholser's two-volume The Bird Life of Texas.
The imperial woodpecker prefers open montane forests made up of Durango, Mexican white, loblolly and Montezuma pines, as well as oaks, usually between above sea level. Most records are from elevations of , but there are records as low as . It feeds mainly on the insect larvae found underneath bark scaled from dead pine trees. There are many reports of more than four individuals, and this grouping behaviour may be related to its foraging specialisation. Breeding has been recorded between February and June, and probably one to four eggs are laid. A mated pair requires a very large area of untouched mature forest to survive, approximately ; outside the breeding season, the birds are reported to form small groups of up to 12 individuals and move about a wide area, apparently in response to the availability of food. The main food source, beetle larvae in snags, is probably distributed in patches and peaks within a short period of time. Consequently, feeding sites are probably best exploited by "nomadic" groups. If operating in groups of seven or eight individuals, the minimum area of old-growth forest for a group is .
The Cornell Lab of Ornithology has released a film of the imperial woodpecker recorded in Mexico in 1956.