Woodpeckers are
part of the family Picidae, that also includes the piculets, wrynecks,
and sapsuckers. Members of this family are found worldwide, except
for Australia, New Guinea, New Zealand, Madagascar, and the
extreme polar regions. Most species live in forests or woodland habitats,
although a few species are known that live in treeless areas, such as rocky
hillsides and deserts, and the Gila woodpecker specialises in
exploiting cacti. A group of woodpeckers
is called a descent.
Members of this family are chiefly known for their
characteristic behaviour. They mostly forage for insect prey on the trunks and
branches of trees, and often communicate by drumming with their beak, producing
a reverberatory sound that can be heard at some distance. Some species vary
their diet with fruits, birds' eggs, small animals, and tree sap, human scraps,
and carrion. They mostly nest and roost in holes that they excavate in
tree trunks, and their abandoned holes are of importance to other cavity-nesting
birds. They sometimes come into conflict with humans when they make holes in
buildings or feed on fruit crops, but perform a useful service by their removal
of insect pests on trees.
Woodpeckers
range from tiny piculets measuring no more than 7 cm (2.8 in) in
length and weighing 7 g (0.25 oz) to large woodpeckers which can be more than 50 cm (20 in) in
length. The largest surviving species is the great slaty woodpecker, which
weighs 360–563 g (12.7–19.9 oz), but probably the extinct imperial
woodpecker and ivory billed
woodpecker were both larger.