Woodpeckers have four strong toes, two pointing forward and two back, with sharp claws that enable them to cling upright to the bark of tree trunks and branches. Their stiff tail feathers also prop them up vertically.
Woodpeckers use their hard, pointed beaks to chisel into wood in search of insects and sap or to excavate nesting and roosting cavities. They also use their beaks to drum out signals during breeding seasons. They have thick skulls, which are protected from the concussive force of drumming by a narrow space around the brain that works as a shock absorber.
With long, flexible, bristled and sticky tongues, woodpeckers can probe small holes in wood to catch insects. Most woodpeckers start feeding at the base of a tree, searching for insects and spiders. Then they move up the trunk in spirals until they reach the larger limbs, where they explore the undersides of branches.
Some species, such as sapsuckers and Hairy Woodpeckers, drill holes in live trees. Others, such as flickers and Downy Woodpeckers, prefer to drill in dying and dead trees also called snags. In either case, the birds tunnel down 6 to 18 inches deep, making the excavation wider at the bottom for the egg chamber.
Both male and female woodpeckers take turns incubating two to eight eggs. Hatchlings are naked and blind. Depending on the species, young leave the nest between 21 and 30 days after hatching.
Species in the Puget Sound area range in size from the larger Pileated Woodpecker, which is about 19 inches long, to the smaller Downy Woodpecker, which is 6 to 7 inches long.
The Northern Flicker is a woodpecker species that has adapted well to cities and suburbs. Unlike other woodpeckers, flickers often feed on the ground where they eat ants. Their wings and tails have reddish-orange undersides.
On occasion, woodpeckers may damage building exteriors, and their drumming may annoy occupants. There are three possible reasons for their behavior that should be assessed before taking remedial action.
Since resident woodpeckers drum against hard, resonant surfaces to proclaim territory, they are likely to return to the same spot repeatedly during breeding season in spring. This can become frustrating when the site is a metal gutter, downspout, or wooden siding of a house, and especially when the woodpecker pecks on it in early morning.
To discourage drumming, change the site surface by covering it with fabric or foam. Providing an alternative drumming site may also work. Nail two boards together at one end and hang them on a secure surface.
If the woodpeckers' drumming activity is not restricted to one site on a building, and if it occurs throughout the year, the birds are likely drilling for food. They are attracted to insect-infested wood where they can drill small holes into the surface to extract the insects.
The first step is to control the insects, and the second is to repair or replace affected timbers, siding, or roofing.
Woodpeckers may also drill cavities for nesting, roosting or storing food. Look for round, deep openings, often near knotholes in boards. In the spring or summer, assume there is an active nest with eggs or hatchlings inside, and wait until you are sure the young have completely left the nest before you begin repairs. Plug small holes with caulking or wood filler, and fill larger ones with wooden plugs, steel wool or wire screen before sealing.
At the first sign of activity, woodpeckers can also be scared away from a site by making noises at a nearby window or against an adjacent inside wall. Strips of foil, fabric or commercially available bird-scare tape hung from eaves might also deter them. You should never scare birds away from a nest with young.
Above: A Northern Flicker (a woodpecker species) at PAWS Wildlife Center