of their diet consists of insects, many of which are potential timber pests. Woodpeckers find insects on the trunks and limbs of trees by sight, or by probing in crevices, scaling off bits of bark or hammering deep into the wood.
Nuts and fruits also comprise an important part of their diet. Most woodpeckers excavate nest cavities and forage for wood-boring insects in trees that are already dead, dying or diseased. Some species, like the northern flicker, may feed on the ground. Others, like the red-headed woodpecker, will catch insects in flight to feed their growing chicks.
All seven of our woodpeckers nest and roost in holes or cavities in trees that they usually excavate themselves. These cavities, pecked in dead or rotting wood, don't hurt the trees and provide important nesting sites for many other cavity users, including chickadees, tufted titmice, bluebirds, tree swallows, screech owls and flying squirrels.
Sometimes woodpeckers use existing cavities or nest boxes, but they generally prefer natural nest sites. Because the nest cavity provides a place to raise their young, woodpeckers don't need to carry in nest material like twigs or leaves. Instead, they line the bottom of the nest cavity with a few wood chips for the eggs to rest on.
All of our woodpeckers lay pure white eggs. They don't need any camouflaging patterns or colors--the nest cavity hides the eggs. When it's time to incubate eggs the female takes most of the day shift, and the male takes the night shift. Both parents share the responsibility of bringing food to young in the nest.
Woodpeckers communicate by means of displays, drumming and vocal calls. Male woodpeckers of most species proclaim their territories by drumming a loud rapid sequence on a dead branch or hollow tree. In some cases, they will drum on wood-sided houses, rain gutters or other metal surfaces. They can be discouraged with balloon scare-eyes or shiny, colorful streamers placed slightly above where the woodpecker is doing damage. A species that naturally has a loud voice will advertise its territory by calling, or by both calling and drumming. When females and males are pairing up during the mating season, they may drum back and forth to each other, duet style. Tapping on suitable nest sites is a ritual part of courtship for some species.
As a general rule, woodpeckers have many aggressive displays they use to defend their territories