American three-toed woodpecker

The American three-toed woodpecker (Picoides dorsalis) is a medium-sized woodpecker native to North America, belonging to the family Picidae. This species is distinguished by its characteristic three toes, a feature shared with its close relatives. It closely resembles the black-backed woodpecker and was formerly considered the same species as the Eurasian three-toed woodpecker.

Description and Characteristics

Adult American three-toed woodpeckers measure between 21 to 23 cm in length, with a wingspan of 37 to 39 cm. Males are slightly larger, averaging 58.3 grams, while females average around 52 grams. Their plumage is predominantly black and white, with the head, wings, and rump being black, and the throat to belly being white. The flanks are adorned with black bars, and the back features black barring on a white background. The tail is black, with the outer feathers barred with black. A notable feature of the adult male is a distinctive yellow cap.

Habitat and Distribution

This woodpecker's breeding habitat is primarily coniferous forests found across western Canada, Alaska, and the western and northeastern United States. They have also been noted on rare occasions in the upper peninsula of Michigan and the northernmost parts of Wisconsin and Minnesota. The species is strongly associated with disturbed, old-growth forests and particularly favors areas with active spruce beetle infestations, as beetle-infested trees are crucial for the cavities they excavate and for other species that rely on these cavities.

Diet and Foraging Behavior

The American three-toed woodpecker forages on conifers, actively searching for wood-boring beetle larvae and other insects. Their diet can also include fruit and tree sap. These birds are known to move into areas with a high concentration of insect-infested trees, often following natural disturbances such as forest fires or flooding. In regions where they overlap with the black-backed woodpecker, the latter species may outcompete them for habitat.

Reproduction and Lifespan

During the breeding season, the female American three-toed woodpecker lays between 3 to 7 eggs, with an average clutch size of 4. These eggs are deposited in a nest cavity excavated in a dead conifer, though sometimes a live tree or a pole may be used. The pair excavates a new nest each year. The maximum lifespan recorded for this species in the wild is 6 years. While generally permanent residents, northern populations may migrate south during winter, and individuals at higher elevations may descend to lower altitudes.