"Pileated woodpeckers are the largest of the common woodpeckers found in most of North America. These crow-sized birds present a memorable sight with their zebra-striped heads and necks, long bills, and distinctive red crests.

Pileated woodpeckers forage for their favorite meal, carpenter ants, by digging large, rectangular holes in trees. These holes can be so large that they weaken smaller trees or even cause them to break in half. Other birds are often attracted to these large openings, eager to access any exposed insects.

Pileated woodpeckers do not discriminate between coniferous and deciduous trees—as long as they yield the ants and beetle larvae that make up much of the birds' diet. Woodpeckers sometimes access these morsels by peeling long strips of bark from the tree, but they also forage on the ground and supplement their diet with fruits and nuts.

The enthusiastic drumming that creates such holes sounds like a loud hammering, and is audible for a great distance. Woodpeckers also drum to attract mates and to announce the boundaries of their territories. Pairs establish territories and live on them all year long.

The birds typically choose large, older trees for nesting and usually inhabit a tree hole. In eastern North America, pileated woodpeckers declined as their forest habitats were systematically logged in the 19th and 20th centuries. In recent decades, many forests have regenerated, and woodpecker species have enjoyed corresponding growth. The birds have proven to be adaptable to changing forest conditions." 

avots - http://animals.nationalgeographic.com/animals/birds/pileated-woodpecker/