Woodpecker

Woodpecker, common name for any of a family of more than 200 species of birds known for their ability to cling to the trunks of trees and dig holes in the wood with their beaks. Woodpeckers have a sharp, straight, chisel-shaped bill and a long, extensile tongue with a hard, spear-shaped tip. The toes are usually in pairs, two in front and two behind, and have sharp, strong claws. In a few species, one of the two rear toes has been lost. Except in the piculets and the wrynecks, the tail is stiffened, with the shafts of the feathers terminating in hard spines, which the birds press against a vertical surface to help support their weight.

Woodpeckers are found throughout most of the world except Australia, are usually solitary in habit, and nest anywhere where there are trees, from rainforests to city parks. The birds eat mainly insects, which they detect by tapping the wood of trees with their bills. They excavate the insects with pickaxe-like strokes of the bill. Woodpeckers generally nest in holes cut into the trunks of trees or even into giant cacti, the female laying several shiny, white eggs in a soft bed of rotted chips at the bottom of the cavity.

The largest species, the imperial woodpecker of the Sierra Madre Occidental of Mexico, is probably extinct. It was about 53 cm (21 in) long, with a long neck and long crest. Closely similar and only slightly smaller, the ivory-billed woodpecker was once distributed across the south-eastern United States and Cuba, and although assumed extinct since the 1940s, was spotted again in 2004 in eastern Arkansas. Still common in the United States and Canada is the crow-sized pileated woodpecker, which is up to 49 cm (19y in) long. It is black, with a red crest, a white line down the long neck, and a white flash in the wings. The most familiar woodpeckers in much of North America and Eurasia are rather small, black-and-white species. The greater spotted woodpecker ranges over most of Europe and northern Asia, except for Ireland and Iceland. It is a handsome black-and-white bird, with red under tail coverts; the male also has a red patch at the back of the head. There is also the middle spotted woodpecker of similar size (about 23 cm/9y in) and the smaller lesser spotted woodpecker, which is only 14 cm (6 in) long and lacks the red under tail coverts. Another species with an extensive European range is the colourful green woodpecker, which as its name suggests has an olive-green back and wings, with light underparts, a yellow rump, and a red crown.

Scientific classification: Woodpeckers make up the family Picidae of the order Piciformes. The imperial woodpecker is classified as Campephilus imperialis, the ivory-billed woodpecker as Campephilus principalis, and the pileated woodpecker as Dryocopus pileatus. The greater spotted woodpecker is classified as Dendrocopos major, the middle spotted woodpecker as Dendrocopos medius, the lesser spotted woodpecker as Dendrocopos minor, and the green woodpecker as Picus viridis.

See also Flicker; Sapsucker.