Dusky Flycatcher

The Dusky Flycatcher is a member of the difficult to identify Empidonax group flycatchers. It is a common breeding species throughout much of mountainous western North America. It breeds from the very southern regions of the Yukon, BC, western Alberta, and mountain regions of the western US. It winters in SE Arizona, SW New Mexico, Mexico and Guatemala.

Adult Male (spring/summer)
Head is gray-olive with prominent white eye- ring and whitish supraloral stripe. Chin is gray, breast and flanks olive-gray, and belly and undertail coverts yellowish-gray. Nape is olive-gray and back, rump and uppertail coverts olive. Wings are black with white edges and two prominent wing-bars. Upper mandible is dark and lower flesh coloured. Appears long-tailed with short primary projection.

Adult Female (spring/summer)
Similar to adult male.

Juvenile
Similar to adults but wing-bars are broader and more buff. Lower mandible is mostly yellow.

General:

Small billed and short-winged Empidonax flycatcher. Length: 13-15. Wing: 20-23cm. Weight: 9-11grams.

Behaviour:

Like most flycatchers, the Dusky perches on prominent dead branches and twigs where it forages by sallying back and forth after flying insects or occasionally pouncing on prey on the ground. Diet consists of insects.

Habitat:

Inhabits open coniferous forest, mountain chaparral, aspen groves, streamside willow thickets and brushy open areas.

Information:

Like other small temperate-zone flycatchers, the Dusky appears to be particularly vulnerable to bad weather. Severe spring rain and snow may kill entire local breeding populations. Likewise weather may account for a significant percentage of total nest failures, equal in many years to what is taken by predators. Nevertheless, survey data suggest that this species is at least holding it’s own, if not growing in numbers, in most regions where it nests. The nest is within a few meters of the ground and is a cup of woven plant fibers and animal hair on an upright crotch in a deciduous tree or shrub. Only females incubate but both adults feed the young. The clutch is 3-4 white eggs. The Dusky may benefit from forestry practices that thin dense coniferous stands or leave small openings.

Similar species:

Hammond’s Flycatcher.

Conservation Status:

Listed as Least Concern. Numbers are increasing.

Capture Rates

The Dusky Flycatcher breeds throughout mountainous western North America. Low capture rates  from April to June and again in September reflect casual migration through coastal areas of the Pacific northwest.

Molt Summary:

PF: HY partial (Sep-Nov): PB: AHY complete (Sep-Nov); PA: SY partial (Feb-May), ASY limited-partial (Feb-Apr). Molt can commence on the summer grounds, but most or all molts usually occur on the winter grounds.

Preformative molt includes 0-5 inner gr covs and often 1-3 terts, but no rects.

1st PA includes 0-6 inner gr covs, usually 1-3 terts, and occasionally 1-2 central rects.

Adult PA usually includes no gr covs or flight feathers

Juv has buff wing bars; juv M = F

DUFL from other Empidonax Flycatchers

Empidonax flycatchers can be separated with caution. Dusky and Hammond’s Flycatchers are very similar Empids, both with grey heads usually contrasting with greener backs, greyish throats, yellowy bellies, narrow bills and almond shaped eyerings and P6 is emarginated in both species.

Dusky has a fairly rounded head but this is not always obvious and depends upon the posture of the bird, and can sometimes appear more peaked. The lores are also often contrastingly paler in Dusky as can be seen on the bird below. The bill is long and narrow with straight sides, the lower mandible variable in colour from yellow to dusky whereas in Hammond’s the bill is small and short with straight sides, the lower mandible again varying in colour.