The
Bicknell's Thrush is a small thrush with a small breeding range, in
scattered locations in the northeastern United States and southeastern
Canada. They were once considered a sub-species of the Gray-cheeked
Thrush (only named a distinct species in 1995), and can be difficult to
distinguish from that species. Hearing a singing Bicknell's Thrush is
the most reliable means of identification. The species has a small
breeding range and populations have been in strong decline. Land-use
change and climate impacts are thought to be behind the decline.
Habitat: Found in high-elevation forests near the
treeline, usually dominated by balsam fir. Such habitats are scattered
and uncommon in their breeding range.
Diet: Feeds on insects, spiders, earthworms, and
other small creatures. They will also consume fruits and berries.
Behavior: Typically forages on the ground or low
in vegetation.
Nesting: The nest is usually placed relatively low
in a small fir tree, between 2 and 12 feet fromt the ground. The nest
is made of grasses, bits of bark, moss, and mud. The female lays
between three and six eggs. The female alone incubates the eggs.
Both parents help to feed the young upon hatching.
Song: The song of a Bicknell's Thrush is a
nasal-sounding series of descending phrases.
Migration: Migratory, breeding in the northeastern
United States and southeastern Canada, and wintering in scattered locations
in the Caribbean.
Feeders: Has been known to attend feeders for
offered fruit.
Similar Species:
Gray-cheeked Thrush,
Swainson's Thrush. Differentiation
from Gray-cheeked Thrush is difficult. Overall, Bicknell's Thrush is
smaller than Gray-cheeked Thrush and is slightly warmer brown.
Idenfication by song is the most reliable means of distinguishing between
them.
Conservation Status: Populations have been in a
strong decline. Land use change and climate change have both been
implicated as potential causes behind the decline. In their limited
breeding range, the forestry practices of thinning or clear-cutting makes
habitat unsuitable for Bicknell's Thrush. Urban and recreational
development, as well as agricultural land use, also threatens local
populations. In the 1960s to 1980s, acid rain was thought to have also
degraded habitat of the species. As a result of declining populations
and continued threats, the
IUCN lists the
Bicknell's Thrush as a "vulnerable" species.