Picoides dorsalis

PLUMAGE: Adult male has a yellow crown, black forehead that is more or less spotted with dull white, black back and sides that are usually broadly barred with white, secondary feathers that are distinctly spotted with white and quills with white spots (Gabrielson and Lincoln 1959). The adult female is similar to the adult male but without any yellow on the head. The female's forehead and crown is usually spotted or streaked with grayish white but sometimes is completely black. Immatures are similar to adults. Young woodpeckers are naked and blind when hatched (Gabrielson and Lincoln 1959). CALLING BEHAVIOR: make tapping sounds while feeding. In the spring and summer you can hear courtship drumming. The call is a rattle similar to that of the hairy woodpecker (PICOIDES VILLOSUS) (Adams, pers. comm.) although the intervals between taps are longer at the beginning of calling episodes. The voice consists of a squeal resembling that of a small mammal and a short quap or quip (Gabrielson and Lincoln 1959).

NEST: Nesting habitat includes coniferous forests (with spruce, larch, or fir trees), or logged areas and swamps. Cavity nest dug by both sexes and are placed 1.5 to 15 m (5 to 50 feet) high in a stump or other dead or dying trees often near water. The entrance is about 4 centimeters by 5 centimeters (1 3/4 by 2 inches), and the cavity is about 25 to 38 centimeters (10 to 15 inches) deep (Oatman 1985).

EGGS: lie on beds of chips within the nest and are ovate, pure white, and only moderately glossy (Gabrielson and Lincoln 1959).

Morphologically very similar to the black-backed woodpecker (PICOIDES ARCTICUS) but is smaller. They are sympatric and occur together ecologically. The barred pattern on back distinguishes it from the black-backed.

Coniferous forest (primarily spruce), less frequently mixed forest. Optimal habitat includes areas with 42-52 snags per 100 acres, with snags occurring in clumps, measuring 12-16 inches dbh and 20-40 feet tall, and mostly with bark still present (Spahr et al. 1991). Cavity nests placed in dead (occasionally live) tree (commonly conifer or aspen). Sometimes nests in utility poles.

Prefers coniferous forest, primarily spruce and balsam fir in the East. It inhabits areas where dead timber remains after fires or logging. It is found less frequently in mixed forest, and occasionally in willow thickets along streams. Also found in high elevation aspen groves, bogs, and swamps.

In the west, they occur in dense coniferous forests, and are associated with subalpine fir and Engelmann spruce at higher elevations; they occur mainly in lodgepole pine forests or in mixed-conifer forests with a lodgepole component at lower elevations (Short 1982). Seem to prefer disturbed coniferous forests with trees that exhibit thin, flaky bark such as spruce and lodgepole pine.

IRRUPTIONS: Periodic irruptions occur, presumably due to a failure of the food supply. Sympatric with Black-backed Woodpecker (PICOIDES ARCTICUS) but irruptions do not coincide possibly due to difference in dependence on live and dead wood insects (Yunick 1985). Less likely to wander in the winter than the black-backed woodpecker. Interspecific competition may be reduced by taking advantage of different foraging heights and having differently sized bills (Peterson 1988).

Forest fire may lead to local increases in woodpecker populations 3-5 years after a fire (Spahr et al. 1991). In the northeastern U.S., territory size of 74 acres and density of 3 pairs per 247 acres (with increases after fire) have been recorded.

Nesting occurs in May and June, young can be found in the nest into July (Oatman 1985, Brewer et al. 1991, Adams pers. comm.). In Montana, nest building is observed in June, with the young out of the nest by early August (Davis 1961). One broods per year. Clutch size usually is four. Incubation, by both sexes, lasts 12-14 days. During incubation birds are rather quiet. Male roosts nightly in nest throughout incubation (Ehrlich et al. 1988). Young are tended by both parents, fledge in 22-26 days, remain with adults for at least a month after fledging. Nesting may be somewhat colonial where food is abundant. Pair bond sometimes lasts multiple years. Nesting times are very similar for the three-toed and black-backed woodpeckers.