In New York and New England, found in sub-alpine forests (elevations >3,000 feet or 920 meters) usually dominated by balsam fir and red spruce. In Canada may breed in more varied habitats such as stunted montane coniferous, mixed second-growth, and dense coastal spruce forests.
The Bicknell's Thrush is of very high importance because of its extremely limited range, small overall population, and its extreme vulnerability to deforestation in its limited winter range. Identifying large and stable populations of this species, as well as determining its precise habitat and area requirements, especially sensitivity to silvicultural practices and other disturbances, will be important for conserving populations.
Male: Upperparts olive-brown with a slightly more reddish tail and primaries, indistinct eye-ring. Underparts are white with bold dark spots on the breast and a slight yellow tinge. Flanks are brownish-gray. Gray-cheeked Thrush is very similar to the Bicknell's, but has more olive on both the back and tail. Bicknell's is also slightly smaller than the Gray-cheeked Thrush, especially when comparing wing length. Separation of these two species away from the known breeding range may be impossible.
Female: Same as male.
Juvenile: Buffy-brown speckled plumage.
Song: The Bicknell's song is very similar to the song of the Gray-cheeked Thrush. It consists of a jumbled series of notes with a final trilled note that is higher than the preceding notes. At the end of the Gray-cheeked Thrush's song the final trilled note is slurred downward.
Calls: The call notes of the Bicknell's and Gray-cheeked thrushes are very similar. A common call may be transcribed as a soft whee-ah or quee-a.
Forages by ground-gleaning or picking up insects or berries from the surface of the forest floor. Young are fed insects.
Eats mainly caterpillars, ants, wasps, beetles, flies; in late summer eats more fruit-blueberries, bunchberries, snowberries, red-berried alder, and wild grapes.
Behavior and displays
Nest site: Generally close to the trunk and well hidden in small- to medium-sized conifers or occasionally in a deciduous tree such as a birch.
Height: 2-12 feet (0.5-4 meters) above the ground, have been recorded as high as 25 feet (7.5 meters) in Nova Scotia.
Nest: Bulky; made mostly of twigs and moss with a little lining of dried leaves, rootlets, and other partially decomposed organic material.
Eggs: 3-4, usually 4. Bluish green, faintly spotted with brown.
Incubation period: Incubation by the female alone, 12-14 days.
Nestling period: Nestlings are altricial (born naked or with a small amount of down, eyes closed, unable to move or feed themselves). The young are fed by both parents, their feather plumes erupt from the sheaths at 6-7 days, and they leave the nest at 10-13 days.
Fledgling period: The young are dependent on their parents for food for approximately 10 days after they fledge.
Broods: One brood per season, but will lay a second clutch if nest fails early in the season.
Cowbird Parasitism: No information.