Alder Flycatcher

The Alder Flycatcher, Empidonax alnorum, is a modestly sized member of the tyrant flycatcher family, with a length ranging from 13 to 17 centimeters and a weight between 12 to 14 grams. Its wingspan extends from 8.3 to 9.4 centimeters. The upperparts are a muted greenish-olive, with the crown a shade darker than the back. A white throat contrasts with a darker breast band, and the eyes are encircled by thin white rings. The bill is of moderate length and width, with a pinkish or yellow-orange lower mandible and a black upper mandible. The wings are generally black, adorned with white wing bars and white-edged innermost secondaries, known as tertials. Juvenile birds display brownish upperparts and yellow underparts, with wingbars tinged in yellowish brown or buff.

Identification Tips

Distinguishing the Alder Flycatcher can be challenging due to its similarity to other species such as the Eastern Wood-Pewee and the Eastern Phoebe, as well as its near-identical cousin, the Willow Flycatcher. However, the Alder Flycatcher is smaller in size and can be recognized by its characteristic behavior of flicking its tail upwards.

Habitat

During the summer breeding season, the Alder Flycatcher inhabits wet, dense, shrubby thickets dominated by alder, maple, and birch trees at elevations below 400 meters.

Distribution

The Alder Flycatcher breeds across most of Canada and Alaska, with its range extending to the northeastern United States. Come autumn, it migrates southward through the eastern United States, Mexico, and Central America, spending the winter in western South America.

Behaviour

The Alder Flycatcher is known for its distinct tail flicking behavior. While its courtship behavior remains somewhat enigmatic, it is believed to involve males pursuing females through the trees.

Song & calls

The song of the Alder Flycatcher is a clear "fee-bee-o," often accompanied by the bird throwing its head back and shaking its tail. Its calls include a "pit" sound when foraging and various calls associated with aggression, territory defense, and excitement.

Breeding

Nests are built low in bushes within shrubby thickets, loosely constructed from grass, weeds, bark, and small twigs, with soft materials like plant down lining the inside. Females are primarily responsible for nest building. The species lays 3-4 creamy-white or buff eggs, speckled with dark markings. Incubation lasts 12-14 days, and both parents care for the altricial young, which fledge around two weeks of age.

Similar Species

The Alder Flycatcher is often confused with the Willow Flycatcher, Eastern Wood-Pewee, and Eastern Phoebe, but can be differentiated by its size and distinctive tail flicking.

Diet and Feeding

The diet consists mainly of insects from the Hymenoptera, Coleoptera, Diptera, Lepidoptera, and Orthoptera families, captured in flight or gleaned from foliage. In winter, some individuals may also consume fruit and seeds.

Conservation status

The Alder Flycatcher is classified as Least Concern by the IUCN Red List. While populations are stable in the United States, there has been a notable decline in Canada. The species has a Continental Concern Score of 9 out of 20 and is recognized as a U.S.-Canada Stewardship species.