Acadian Flycatcher

The Acadian flycatcher (Empidonax virescens) is a small passerine bird native to North and South America, where it inhabits wet riverside forests. They spend their days swiftly maneuvering through trees as they search for insects and small fruit. These solitary birds sing their songs early in the morning and defend their riverside nests with a monogamous partner. Discover all the fascinating Acadian flycatcher facts, including where they live, what they eat, and how they behave.

Where to Find the Acadian Flycatcher

Acadian flycatchers live in North and South America in over 15 countries, including the United States, Mexico, Venezuela, Colombia, and the Bahamas. Their range includes Southwestern Ontario and the Southeastern United States during spring and summer. They migrate through Mexico and Central America before reaching their wintering grounds in Northwestern South America. They breed in wet deciduous forests, such as swamps and dense riverside woods, and live in woodlands in their tropical winter homes. Search for these birds in the mid-story of tall trees and look for quick movements as they sally out to catch insects. 

Acadian Flycatcher Nest

They nest in tall trees or large shrubs in horizontal forks away from the trunk. Females form a loose cup made from weed stems, twigs, and grass and lined with plant down. They may use spider webs to hold the material together, but the nest often has a sloppy appearance, making it look abandoned.

Scientific Name

The Acadian flycatcher (Empidonax virescens) belongs to the Passeriformes order in the Tyrannidae family, which encompasses the tyrant flycatchers with over 400 species. The Empidonax genus includes small flycatchers, and the name is Ancient Greek for “gnat” and “master.” They were discovered in Acadia (present-day Nova Scotia), but they do not inhabit this area today.

Size, Appearance, & Behavior

Acadian flycatchers are small passerine birds, measuring 5.5 to 5.9 inches long and weighing 0.4 to 0.5 ounces, with an 8.7 to 9.1-inch wingspan. They have long tails, broad bills, large heads, and long wings. Adults are olive-green above and whitish below, with dark wings and white wingbars. Their bills are dark above and orange-yellow below.

These birds are mostly solitary, except during breeding, when they form monogamous pairs and nest near other flycatchers. They typically spend their time perched in the mid-canopy of their forest habitat, sallying out to catch insects and returning to their perch. They sing their songs early in the morning, an emphatic two-note “peet-seet!” The Acadian flycatcher is fun to watch as it quickly maneuvers through trees, using rapid wingbeats to take direct flights. Their exact speed is unknown.

Migration Pattern and Timing

Acadian flycatchers are long-distance migrants who begin their spring migration in early March and their fall migration as early as July or August. They breed in the southeastern portion of the United States, from South Dakota down to Texas and east through New York and Florida. During migration, they travel along the Gulf Coast down to Mexico and through Central America before reaching their wintering grounds in northern South America (Colombia and Venezuela).

Diet

Acadian flycatchers are primarily insectivores that forage by watching from a perch.

What Does the Acadian Flycatcher Eat?

Their diet consists of wasps, bees, caterpillars, ants, flies, beetles, moths, spiders, and millipedes. They also supplement their diet with some small fruits and berries. They select a perch from the mid-canopy, where they sit and watch before flying out to catch insects mid-air. This flycatcher will also snatch bugs from foliage while they hover.

Predators, Threats, and Conservation Status

The IUCN lists the Acadian flycatcher as LC or “least concern.” Due to its extensive range and extremely large, stable population, this species does not meet the “threatened” status thresholds. Their biggest threats include habitat loss and degradation from forest clearing as a result of agricultural and urban developments. They also face future climate threats, like spring heat waves, which can endanger nestlings.

What Eats the Acadian Flycatcher?

Their predators include crows, hawks, owls, jays, cuckoos, domestic cats, rat snakes, squirrels, chipmunks, and mice. Their young are more likely to fall prey, but parents build their nests in trees hanging over bodies of water because they are easier to defend. Males give rapid alarm calls to warn of intruders and may become aggressive if necessary. 

Reproduction, Young, and Molting

Their breeding season falls between April and August, and they form monogamous long-term pair bonds, where they mate with one partner for many years. However, some males have been observed practicing polygamy and will mate with several females. Females lay two to four creamy white eggs and incubate them for 13 to 15 days. Their young fledge the nest when they can fly, around two weeks after hatching. The father feeds the fledglings while the mother begins incubating the second batch of eggs. They reach sexual maturity around one year and live an average of three years, but they can live up to 12.

Population

The global Acadian flycatcher population is estimated to number 5.2 million mature individuals. The species declined slowly from the 1970s to 2017, but recent trends suggest their numbers are stabilizing and possibly increasing slightly.