Acadian Flycatcher Identification Guide

Key Field Marks

• Small flycatcher, about 14-15 cm (5.5-6 in), with a fairly large, wide bill for an Empidonax
• Olive-green upperparts, whitish underparts with a pale olive-yellow wash on the flanks and belly
• Two bold, pale (whitish to pale buff) wing bars
• Distinct whitish eye-ring, evenly thin all around
• Lower mandible entirely pale/pinkish, contrasting with the darker upper mandible
• Tail relatively long; overall a "long-winged, big-billed" impression among Empids

How to Separate It From Similar Species

• Acadian Flycatcher belongs to the notoriously difficult Empidonax genus, where plumage differences are subtle; voice is the most reliable field mark.
• Willow Flycatcher and Alder Flycatcher: both are drabber, browner-olive, with less contrasty wing bars and different calls ("fitz-bew" for Willow, "free-beer" for Alder); Acadian favors shaded forest interior rather than wet shrubby edges.
• Least Flycatcher: smaller, grayer, with a bolder white eye-ring and a shorter primary projection; gives a snappy "che-BEK" song, very different from Acadian's explosive call.
• Yellow-bellied Flycatcher: brighter yellow-green overall with a bolder, more complete eye-ring and a rounder head; breeds in northern bogs rather than southern deciduous forest.
• Structurally, Acadian shows the longest primary projection and largest bill of the eastern Empidonax flycatchers, useful with good views.

Where & When to See It

• Breeds in mature, closed-canopy deciduous and mixed forest, especially in shaded ravines, floodplains, and forest with a nearby stream or seep, across the eastern and southeastern United States.
• A long-distance Neotropical migrant, wintering from southern Mexico through Central America to northern South America; arrives on breeding grounds in late April to May and departs by early fall.
• Stays high in the shaded midstory to subcanopy, making it easier to hear than see.

Voice & Behavior Cues

• Song is an explosive, two-noted "pizza!" or "PEET-sah!" with the accent on the first syllable, delivered from a perch in the forest interior — the single best clue to identification.
• Call note is a sharp "peek" or "peet."
• Sits upright on a horizontal branch and sallies out to catch flying insects, returning to the same or a nearby perch (classic flycatcher behavior).
• Builds a shallow, saucer-like nest of grasses and plant fibers, often decorated with hanging streamers, suspended in a horizontal fork over water or a ravine.