the american three-toed woodpecker (picoides dorsalis) is a medium-sized woodpecker (family picidae) .
this woodpecker has a length of 21 cm (8.3 in), a wingspan of 38 cm (15 in), and an average weight of 55 g (1.9 oz); its maximum lifespan in the wild is 6 years .
it closely resembles the black-backed woodpecker , which is also three-toed .
until recently , it was considered to be the same species as the eurasian three-toed woodpecker , (p .
tridactylus) .
adults are 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 .
the breeding habitat is coniferous forests across western canada , alaska and the midwestern united states .
it has also been breeding in various spots in michigan's upper peninsula .
the female lays 3 to 7 but most often 4 eggs in a nest cavity in a dead conifer or sometimes a live tree or pole .
the pair excavates a new nest each year .
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 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 .
this bird is likely to give way to the black-backed woodpecker where the two species compete for habitat .
