The 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).
American Three-toed Woodpeckers 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, personal communication) 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).
For a comprehensive review of the conservation status, habitat use, and ecology of this and other Montana bird species, please see Marks et al. 2016, Birds of Montana.
Morphologically American Three-toed Woodpecker is very similar to the Black-backed Woodpecker (Picoides arcticus) but is smaller. They are sympatric and occur together ecologically. The barred pattern on the back distinguishes it from the Black-backed Woodpecker.
Western Hemisphere Range
Nesting habitat includes coniferous forests (with spruce, larch, or fir trees), or logged areas and swamps. A cavity nest is dug by both sexes and is placed 1.5 to 15 meters (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). The eggs lie on beds of chips within the nest and are ovate, pure white, and only moderately glossy (Gabrielson and Lincoln 1959).
Diet consists of primarily of larvae of bark beetles. Also, tree sap and insects.
In Glacier National Park, breeding density hit 13.5 birds per 100 acres in lodgepole pine during a pine beetle epidemic, probably due to the ability of birds to nest in lodgepole pine. In Oregon, home ranges for 3 radioed individuals were 751, 351, and 131 acres. Intraspecific home range overlap appeared limited (Goggans et al. 1989). Differences in diet between sexes noted.
Nest building was observed in June, with young out of the nest by early August (Davis 1961). Flying young were observed during late July near Fortine.