The Three-toed Woodpecker, Picoides tridactylus, is a medium-sized woodpecker. The adult is 8.5 to 9.5 inches in length. It is black on the head, wings and rump, and white from the throat to the belly. The flanks are white with black bars. The back is white with black bars, and the tail is black with the white outer feathers barred with black. The adult male has a yellow cap. In North America, the Three-toed Woodpecker can be confused with the Black-backed Woodpecker, which it closely resembles.
The breeding habitat is coniferous forests across western Canada, Alaska and the Midwestern United States, and across northern Eurasia from Norway to Korea. There are also populations in the Alps and the Carpathian Mountains. This bird is normally a permanent resident, but northern birds may move south and birds at high elevations may move to lower levels in winter.
Three-toed Woodpeckers nest in a cavity in a dead conifer or sometimes a live tree or pole. The pair excavates a new nest each year. They forage on conifers in search of wood-boring beetle larvae or other insects. They may also eat fruit and tree sap.
These birds often move into areas with large numbers of insect-infested trees, often following a forest fire or flooding. In North America, this bird is likely to give way to the Black-backed Woodpecker where the two species compete for habitat.