Townsend’s Warbler

A colourful, distinctive wood-warbler that breeds among the treetops of mature fir forests in the Pacific Northwest, Townsend’s Warbler also nests in montane spruce-fir forests in Idaho, Montana, and northwest Wyoming, and boreal forests in Alaska and the Yukon Territory. In September, it begins its southward migration to California and the highlands of Mexico and Central America, where it is the most common of all species (including residents) in some locales.

Adult Male (spring/summer)

Crown, chin and throat black. Yellow supercilium; black auricular with yellow spot under black eye and yellow submoustachial stripe. Upper breast black abruptly changing to yellow below and belly white. Flanks light yellow with black streaking. Undertail coverts white with small black flecks. Back olive with faint black streaks; rump and uppertail coverts olive. Wings and tail black with white feather edging and two white wing bars. Beak, legs and feet are black.

Adult Female (spring/summer)

Differs from male as female is slightly duller in black areas and back feathers are fringed green.

Juvenile

Similar to adult female, but distinct dark olive auricular; back has indistinct streaking; throat and breast yellow; sides indistinctly dusky streaked; tail-feathers more pointed.

General:

Medium-sized, rather long-tailed warbler with rather small bill. Length: 12cm. Wing: 20cm. Weight: 7-11grams.

Behaviour:

Foraging birds on the breeding grounds spend most of their time high in the crowns of tall conifers and are thus often difficult to observe. There they glean insects from leaf surfaces and needles and, ‘hawk’ and ‘hover-glean insects. In migration and winter, foraging takes place at all levels, even near the ground, and in a broader variety of trees. During those seasons they often join mixed flocks of kinglets, chickadees and other warblers.

Habitat:

Shady moist coniferous forests, where it spends much of its time high in the trees foraging for weevils, leafhoppers, scale insects, and caterpillars.

Information:

Townsend’s Warbler was among the many species first collected by John Kirk Townsend during his expedition with Thomas Nuttall through the Rocky Mountains to the Pacific Coast in 1834. With the exception of recent studies of winter species interactions and breeding biology, most information of the life history of the Townsend’s Warbler is anecdotal or consists of isolated observations. Nests are built high in conifers, exceptionally as low as 8ft. and as high as 100ft. The nest is a bulky but shallow cup of plant fibers and bark, lined with moss, plant downs and hairs; the nest is placed on al limb well out from the trunk and usually protected above by a spray of needles. 3-5 white eggs wreathed and speckled with brownish markings.

Similar species:

Black-throated Gray Warbler, Golden-cheeked Warbler, Hermit Warbler.

Conservation Status:

Listed as Least Concern. Populations are stable or increasing slightly.

Townsend’s Warbler preferred habitat is open coniferous or mixed coniferous-deciduous forests and breed slightly more north than southern British Columbia. They are therefore not seen in high numbers around our banding station. Capture rates start with a few spring individuals returning to breeding grounds and again in August and continue through October reflecting capture of dispersing juveniles passing through during fall migration to their southern wintering grounds.

Molt Summary:

PF: HY partial; PB: AHY complete; PA limited
Preformative molt usually includes all med & gr covs and often the greater alula but no terts or rects
1st PA occasionally includes 1 -2 inner gr covs but no med covs
Otherwise PA’s limited primarily to head and upper parts