Acadian Flycatcher vs Alder Flycatcher

The Acadian Flycatcher and Alder Flycatcher are both small, greenish Empidonax flycatchers, but they can be distinguished by habitat preference and vocalizations. The Acadian Flycatcher is more often found in mature deciduous forests, while the Alder Flycatcher prefers shrubby, wet areas. Their songs are the most reliable way to tell them apart in the field.

Listen for song: Acadian's "peet-sah" vs. Alder's "fee-bee-o." Check habitat: Acadian in mature forests, Alder in shrubby wetlands. Observe behavior: Acadian higher in canopy, Alder lower in shrubs. Note primary length: Acadian has longer primaries.

Both species are similar in size, typical of small flycatchers, but the Acadian Flycatcher has notably longer primaries.

Both species have a similar greenish-olive plumage with pale underparts. The Acadian Flycatcher may appear slightly brighter, but this is not a reliable field mark.

Both species exhibit typical flycatcher behavior, sallying from perches to catch insects. The Acadian Flycatcher is more likely to be seen in the canopy, while the Alder Flycatcher is often found lower in shrubs.

Acadian Flycatchers favor mature deciduous forests, often near water, and can also be found in coniferous forests in the Southeast. Alder Flycatchers are more associated with shrubby, wet areas, often in northern and boreal regions.

The Acadian Flycatcher's song is an explosive "peet-sah," while the Alder Flycatcher has a distinctive "fee-bee-o" song. These vocalizations are the most reliable way to distinguish them.