|Species: Black-Throated Gray
Warbler Dendroica nigrescens
This is a striking
black, gray and white member of the ‘virens’ group’, 5 species which
form a closely related group of warblers. The other species which
compromise this group are the Golden-Cheeked, Black-Throated Green,
Townsend’s, and Hermit Warblers.
It is an elegant warbler of western North America found and first
described by John Kirk Townsend near Ft.William (Portland), Oregon.
The Black-Throated Gray was already known there as “Ah Kah a Qual”
by the Chinook.
It breeds generally west of the Rocky Mountains from northern Mexico
to British Columbia. First arrivals in sw B.C. are usually during
the second week of April.
General: This is an averaged sized foliage-gleaning wood
warbler. It is 11-13 cm long and weighs 7-10 g.
Black head, chin and throat, horizontal white line above eyes and
below cheeks; upper parts blue-gray; under parts white with
black-streaked sides; two white wing bars; tiny spot of bright
yellow in front of eyes(lores).
Similar to adult male but black of the head not as dark. The chin is
always white and most individuals have a white throat with a band of
black across the lower throat and a patch of black at the sides of
the rear throat. Yellow lores are not as bright yellow as males.
Black on throat less solid than in adult male. Cheek varies from
blackish to slatey brown. Black of crown mostly restricted to sides,
center of crown gray. Yellow lores dull yellow.
The general plumage of the males is almost identical to the
Townsend’s Warbler. The Townsend’s has greens and yellows rather
than black and white. Black and White Warblers may cause confusion,
but all Black and Whites show a median crown stripe and lack yellow
Watch the Black-Throated Gray foraging, deliberately gleaning and
reaching, with occasional hover-gleaning and short sallies.
Common in a great variety of woodlands throughout its range, it is
home in a wide variety of semi-arid deciduous and conifer woodlands
of the western U.S. and southwestern B.C. Most foraging is at
mid-level within the canopy.
This bird tends to
be relatively tame and is often readily observed at close quarters
as it forages methodically among foliage. Nevertheless, little is
known about many aspects of its natural history.
It is a short-to-medium distance Neotropical migrant, and like many
such migrants, is insectivorous.
The nest is a deep, compact cup of plant fibers and grasses, bound
with spider webs and lined with fir, feathers, and hair. Nests are
often placed low (3-10ft.) in bushes, but frequently are placed at
20ft. or more well out on conifer limbs. There are usually 4 white
or cream-white, speckled brown eggs.
Black-Throated Gray Warbler populations do not seem to have been
affected by human activities to any great extent, but changes are
difficult to assess because so little is known about this species.
The Black-throated Grey Warbler's preferred habitat is open
coniferous or mixed coniferous-deciduous woodland, therefore
not seen in high numbers around our banding station. Capture
rates (2010-2012; standardized as birds captured per 100 net
hours) begin in July and continue through October when
activity picks up as juveniles disperse and prepare for
their relatively short migration southward.