Woodpeckers are a unique and interesting group of birds that occupy much of the forested regions of Alaska. Seven species occur in the state: the northern flicker, red-breasted sapsucker, yellow-bellied sapsucker, and hairy, downy, three-toed, and black-backed woodpeckers. Very little is known about the ecology of woodpeckers in Alaska. Most of the following information comes from studies conducted in other parts of North America.

General description: Woodpeckers are well-adapted for a life on tree trunks and limbs. Woodpeckers have stiff tail feathers which act as a brace for moving along vertical tree trunks. Their feet are also adapted for climbing and hanging. All woodpeckers have two toes pointing forward and either one or two toes pointing to the side or slightly backward. Thus, woodpeckers are able to grip a tree trunk surface with opposable toes.

Woodpeckers have evolved chisel-like bills coupled with strong neck and head muscles. These adaptations give them the ability to chip away bark and wood to uncover insects for food, as well as to create nesting cavities. The extremely long, barbed tongue (some species are able to extend their tongue two inches beyond the bill tip) enables the bird to spear insects hidden deep in small holes.

Even a novice bird-watcher can easily identify a woodpecker by its behavior. Only two other birds in Alaska, the much smaller brown creeper and red-breasted nuthatch, spend so much time moving vertically on tree trunks. All woodpeckers can be recognized by their undulating flight—wings flapping as the bird goes up and wings folded on the way down.

Life history: Reproductive habits of Alaska's woodpeckers are similar in many aspects. Four species (hairy, downy, three-toed, and black-backed) remain throughout the year and begin breeding activities during late winter. Northern flickers, red-breasted sapsuckers, and yellow-bellied sapsuckers migrate south in winter, returning in early spring. The male sets up a territory by “drumming.” This loud repetitive noise is made by hammering the bill against a resonating surface such as the trunk of a dead tree. Woodpeckers use various displays, including head-weaving and body-bobbing, during courtship and as signs of aggression toward intruders.

After pairing, nest construction begins. All species in Alaska usually excavate new nest holes and chambers each year. Woodpeckers do not bring in nest material; eggs are laid on the wood chips that dropped down during cavity construction. Both sexes play a large role in nesting; both construct the nest site and share the duties of incubation, which takes about two weeks. Young are altricial, meaning they are blind and naked at hatching. The adults are then kept busy, one obtaining food while the other broods the young. Once the young have grown feathers and can maintain their own body heat, both adults bring in food. Adults regurgitate partially digested insects to feed the young. Later, whole insects may be brought to the growing chicks. Young leave the nest after 25-30 days. They may then remain with the parents for only a few days before becoming full independent.

Management: Woodpeckers play an important part in Alaska's forest ecosystems. Wood-boring and other insects which are inaccessible to other birds are consumed by woodpeckers. Studies in other parts of North America have estimated very large numbers of insects consumed; one black-backed woodpecker may eat 13,500 beetle larvae annually. In some areas, woodpeckers are thought to be able to eat enough larvae to prevent outbreaks of insects that damage and kill trees. Since wood and saw logs are very valuable in much of Alaska, woodpeckers could play an important economic role. Aesthetically, their value is incalculable. The sound of a drumming woodpecker is a sign of the approach of spring. The sight of a three-toed or black-backed woodpecker is eagerly sought by bird-watchers.

Because they are dependent on certain forest characteristics, including snags and trees with heartrot for drumming, nesting, roosting, and feeding sites, woodpeckers are vulnerable to alterations of forest habitats. Short rotation logging or selective cutting of trees with insect damage or heartrot have caused population declines of some species of woodpeckers in other parts of the world. Intensive cutting of dead trees for firewood is also potentially harmful to woodpecker populations. The role of woodpeckers as forest insect predators should not be overlooked by those seeking to improve timber production.

The northern flicker (Colaptes auratus) is probably the most easily identified woodpecker in Alaska. Two races are found here—the red-shafted (shaft is the stiff part of a feather), found primarily in Southeast Alaska, and the yellow-shafted, which predominates throughout the rest of the state. Both have a conspicuous white rump patch, seen especially in flight, and on the male, a black or red “mustache” extending back of the bill. Flickers can also be identified by their loud call that sounds like “wake-up, wake-up, wake-up.”

Flickers have a less chisel-like bill then other woodpeckers, thus they cannot get to wood boring insects. Instead, they often feed on the ground and pick insects off tree trunks and branches. Ants are a favorite food.

Two species of sapsuckers occur in Alaska. Yellow-bellied (Sphyrapicus varius) and red-breasted sapsuckers (S. ruber) were formerly considered two races of the same species but are now classified separately. Yellow-bellied sapsuckers have black and white heads and chests with red only on the forehead and under the chin. They have been seen only a few times in Alaska. Sapsuckers with red heads, necks, and chests are red-breasted sapsuckers. They occur only in Southeast Alaska and are uncommon even there. Male and female sapsuckers are similar and difficult to distinguish in the field.

Sapsuckers are appropriately named as they obtain a large part of their food by “tapping” trees for sap. Small, square holes are drilled in rows around a tree trunk; these act as miniature wells. Sapsuckers use their long tongues with their special brush-like tips to lap up the fluid that fills the holes. These birds also eat the insects which the flowing sap attracts.

The hairy woodpecker (Picoides villosus) and downy woodpecker (P. pubescens) frequent bird feeders filled with animal fat or suet during the winter. Hairy and downy woodpeckers look similar, being a vivid black and white with a white stripe down the back. Downy woodpeckers essentially look like miniature hairy woodpeckers but have much shorter bills in proportion to head size. Both males have bright red neck patches.

The three-toed woodpecker (P. tridactylus) is the most abundant and widespread woodpecker in Alaska, primarily inhabiting mature spruce forests. This woodpecker is predominantly black and white, although males have bright yellow foreheads. It is most easily distinguished from other woodpeckers by the black and white barred stripe on its back and sides.

Black-backed woodpeckers (P. arcticus) occur in forested parts of Alaska but are uncommon and difficult to observe. This bird is very similar in appearance to the three-toed except for its larger size and all black back. They often feed on the lower trunks of dead trees and prefer to nest in old snags near openings in the forests, such as bogs. Both black-backed and three-toed woodpeckers have only three toes rather than the four of other woodpeckers. This in no way impairs their ability to climb. They probably spend more time on tree trunks than any other woodpeckers in Alaska.

Text: William A. Lehnhausen
Illustration: Lyons
Revised and reprinted 1994