Birds
Pileated Woodpecker
Dryocopus pileatus · also called the Woody Woodpecker bird
The pileated woodpecker is the big one — a crow-sized bird with a flaming red crest that announces itself with a ringing call and a drumroll you can hear across a valley. Where it lives, its work is written all over the dead trees.
Overview
Pileated woodpeckers live in mature and old-growth forest and well-wooded suburbs across much of North America, wherever there are large trees, especially dead and dying ones, and a supply of carpenter ants. A pair holds a large territory year-round and does not migrate. The species had declined by the early 1900s as forests were felled, but has recovered strongly as second-growth woodland has aged.
Built for demolition
Everything about the bird is engineered around striking wood hard, thousands of times a day:
- A chisel-tipped bill driven by powerful neck muscles.
- A shock-managing skull — dense, slightly spongy bone, a snug-fitting brain, offset bill halves, and a hyoid bone that loops over the top of the skull as a natural restraint.
- A long, barbed, sticky tongue that darts into ant tunnels and hooks prey out.
- Zygodactyl feet (two toes forward, two back) and stiff tail feathers that brace the bird against the trunk like a tripod.
Feeding and its side effects
Pileated woodpeckers feed heavily on carpenter ants, following the ants’ galleries deep into a trunk and leaving the trademark rectangular excavations. In doing so they help control forest insect populations and accelerate the breakdown of dead wood. Their discarded nest and roost cavities are prime real estate for a long list of other animals — ducks, owls, squirrels, martens, bats — making the pileated a keystone species in forest ecosystems.
Reproduction
Each year the pair chisels a new nest cavity, usually high in a large dead tree, a job that takes three to six weeks. The female lays around four white eggs, and both parents incubate them and feed the nestlings by regurgitating insects. The young leave the nest after about a month but stay with the parents into the autumn, learning where and how to forage.
Status
The pileated woodpecker is Least Concern and increasing. Its main need is large trees and standing deadwood, so it benefits from forestry practices and park management that leave old and dead trees in place, and from the general maturing of North America’s regrown forests.
Pileated Woodpecker: common questions
How does a woodpecker hammer without hurting its brain?
Several features work together. The skull bone is dense but slightly spongy where it meets the beak, spreading and absorbing the force; the brain is small, smooth, and tightly packed so it does not slosh; the upper and lower parts of the beak are slightly unequal, directing shock away from the braincase and into the neck and body; and a long bone-and-muscle structure called the hyoid apparatus wraps around the skull like a shock-absorbing strap. The bird also strikes in near-straight lines to avoid twisting forces.
What are the rectangular holes in dead trees?
Feeding excavations made by pileated woodpeckers hunting carpenter ants. Unlike the round entrance hole of a nest, feeding holes are distinctively rectangular or oblong and can be very large and deep — a bird will chisel out a cavity big enough to put your fist in, following ant galleries through the wood. Big piles of fresh, chunky wood chips at the base of a dead tree are a reliable sign one is working nearby.
Are pileated woodpeckers rare?
No — they are fairly common and their numbers are rising as forests cleared in past centuries regrow and mature. They were probably scarcer a hundred years ago. The bird they are often confused with, the ivory-billed woodpecker, is a different, larger species that is considered extinct or all but extinct; sightings of a big black-and-white woodpecker in North America today are almost always pileateds.
Why is the pileated woodpecker important to other animals?
It is a keystone cavity-maker. Its large nest and roost holes, once abandoned, are used by wood ducks, owls, kestrels, flying squirrels, pine martens, bats, and many other animals that cannot excavate their own. Its deep feeding holes also open up dead wood to fungi and other insects, and expose ant colonies that other birds then exploit.