Dusky Flycatcher

The Dusky Flycatcher (Empidonax oberholseri) is a small, insectivorous songbird native to the montane regions of western North America. Like other members of the genus Empidonax, it is notoriously difficult to distinguish from its close relatives based on plumage alone. It occupies brushy, open woodlands and shrubby mountain slopes, where it can often be seen perched on conspicuous twigs, ready to dart out and capture passing insects. Understanding its subtle physical details, vocalizations, and habitat choices is key to confident identification.

Field Identification

Identifying the Dusky Flycatcher requires close attention to structural proportions, plumage nuances, and behaviors.

Key Field Marks

• Plumage: Olive-gray upperparts with a grayish-white throat and breast. The belly often shows a pale yellow wash, especially in fresh autumn plumage. It has two whitish wing bars and a distinct, slightly almond-shaped white eye-ring.
• Bill: Medium-short in length. The lower mandible is typically dull pinkish-orange, often showing a dark tip on the terminal third to half.
• Primary Projection: Moderate. The visible tips of the primary wing feathers extend only moderately beyond the secondary feathers, shorter than Hammond's Flycatcher but longer than the Gray Flycatcher.
• Tail Movement: When perched, the Dusky Flycatcher frequently flicks its tail in a gentle, upward-and-returned motion.

Distinguishing from Similar Species

• Hammond's Flycatcher (Empidonax hammondii): Hammond's has a shorter bill, longer primary projection (long wingtips), and a darker throat. It prefers tall, closed-canopy mature conifers and has a sharper, squeakier call note.
• Gray Flycatcher (Empidonax wrightii): The Gray Flycatcher has completely gray upperparts, a longer bill with an entirely pale lower mandible, and a highly diagnostic, downward tail-wagging motion. It prefers dry sagebrush and pinyon-juniper habitats.
• Willow Flycatcher (Empidonax traillii): Lacks a prominent eye-ring, has a larger bill, and a different vocalization profile.

Habitat and Range

Habitat Preferred

During the breeding season, the Dusky Flycatcher favors open, brushy habitats. This includes mountain shrublands, clearcuts, burned-over forests with regenerating scrub, open coniferous forests with a thick undergrowth, and mixed forests containing willow and aspen. They generally prefer drier, more open scrubby areas compared to the canopy-dwelling Hammond's Flycatcher.

Range and Migration

This species breeds throughout the mountainous regions of western North America, from Alaska and western Canada down through the western United States to northern New Mexico and Arizona. It is a medium-distance migrant, traveling south in autumn to spend the winter in the highlands of Mexico and parts of south-central Arizona.

Behavior and Ecology

Foraging and Diet

The Dusky Flycatcher is an active insectivore. It utilizes a typical "sit-and-wait" flycatcher strategy, perching on low-to-medium branches in shrubbery before sallying out to capture flying insects in mid-air (hawking) or gleaning them from foliage. Common prey includes beetles, flies, bees, wasps, and moths.

Vocalizations

Because physically identifying Empidonax species is so challenging, learning their songs and calls is essential:

• Song: A dry, rhythmic, three-part song often transcribed as seet (or churp), followed by a higher du-wee, and ending with a low-pitched pree-it. These phrases are repeated in various sequences.
• Call: A distinct, dry, and soft whit call, which is softer than the metallic pit of the Hammond's Flycatcher.

Nesting

Nests are typically cup-shaped, woven of grasses, bark shreds, plant fibers, and lined with finer materials like hair and down. Unlike Hammond's Flycatcher, which nests high in mature conifers, the Dusky Flycatcher nests much lower to the ground, usually placed 1 to 3 meters high in the fork of a deciduous shrub or sapling (such as willow, alder, or wild rose).