Acadian Flycatcher

The Acadian Flycatcher (Empidonax virescens) is a small, insect-eating songbird of the tyrant flycatcher family. Like other members of the notoriously challenging Empidonax genus (commonly called 'empids'), this species is difficult to identify by sight alone but is highly recognizable by its vocalizations, structure, and habitat. It is a classic interior forest species, restricted to dense, shaded understories of mature deciduous woods, where its greenish-olive tones match the leafy environment. It is a migratory species, spending its breeding seasons in eastern North America and winters in the Neotropics.

Identifying the Acadian Flycatcher requires a combination of visual, structural, and auditory clues.

Key Field Marks

• Plumage: Overall greenish-olive upperparts and pale underparts. The flanks show a subtle yellowish wash, and the throat is clean white or very pale gray.
• Face: Features a distinct, bold white-to-yellowish eye-ring, which can sometimes appear slightly oval or teardrop-shaped.
• Wings: Two bold, contrastingly light (yellowish or whitish) wingbars. The primary projection—the distance the primary flight feathers extend beyond the folded secondary feathers—is notably long compared to similar species.
• Bill: Relatively large, broad-based, and flat. Critically, the lower mandible is completely orange-yellow or flesh-colored with no dark tip.

Similar Species

• Least Flycatcher: Smaller with a shorter bill, bolder round eye-ring, much shorter primary projection, and prefers drier, more open woods.
• Willow / Alder Flycatchers: Show warmer, browner upperparts, a less distinct or absent eye-ring, more rounded heads, and shorter primary projections.
• Yellow-bellied Flycatcher: Features a yellow throat and entire yellow underparts, whereas the Acadian Flycatcher retains a white throat.

During the breeding season, the Acadian Flycatcher is strongly associated with undisturbed, mature deciduous forests. Key habitat traits include:

• Forest Interiors: Shaded understories of damp forests, ravines, swampy woods, and river valleys near running water.
• Preferred Trees: Often nests in beech, hemlock, maple, or sweetgum trees.
• Breeding Range: Spreads across the eastern United States, from southern New England, southern Ontario, and the Great Lakes, south to Florida and eastern Texas.
• Migration: Undertakes long-distance nocturnal migrations to winter in the humid lowland forests of Central America and northwestern South America.

Feeding

Acadian Flycatchers are aerial insectivores. They typically hunt from low, shaded branches in the understory. They sally out to capture flying insects mid-air (hawking) or hover briefly to glean insects, caterpillars, and spiders from the undersides of leaves and twigs.

Voice & Call

The most reliable diagnostic tool is its primary song: a loud, explosive, two-syllabled 'peet-sa!' or 'fitz-bew' with the accent strongly placed on the first syllable. It also emits a sharp, metallic 'peep' or 'speek' call note.

Nesting

The female builds a highly unique, nest suspended like a hammock in the fork of a low, horizontal branch, often hanging directly over running water or a deep ravine path. Constructed loosely from plant fibers, grasses, and spiderwebs, the nest typically features long, dangling strands of plant material underneath, mimicking river debris to camouflage the structure from predators.