- 5.9 in
- 9.1 in
- 0.4–0.5 oz
- Curiously, no information exists on the ability of the Acadian Flycatcher to walk or hop. It is an excellent flier, though, extremely maneuverable and able to hover and even fly backward. It has been observed bathing not by standing in water, but rather by diving into water from above, hitting the water with its chest, and then returning to a perch to preen and shake.
- The male defends his territory with a characteristic "peet-sah" song. The female may use the same call in stressful situations, such as when disturbed from the nest or right after being released from a mist net.
- The Acadian Flycatcher is a common host to the brood-parasitic Brown-headed Cowbird, which lays its eggs in other birds' nests. Nests are parasitized more in small woodlots than in large tracts of forest. The frequency of parasitism is lower for the flycatcher than for other bird species in the same forests. From the cowbird's perspective the Acadian Flycatcher does not seem to be a particularly good host: only 16% of cowbird young in Acadian Flycatcher nests fledged successfully.
- The oldest Acadian Flycatcher was over 12 years old, when it was recaptured and rereleased during a banding operation in Louisiana.
- Breeds in mature forest, especially deciduous woods, along streams, in ravines, and in swamps.
- Winters in lowland tropical forest and second growth.
Insects, insect larvae, and other arthropods.
- Clutch Size
- 1–4 eggs
- Egg Description
- Creamy to buffy white with some small brownish spots at larger end.
- Condition at Hatching
- Helpless with some white down.
Nest a shallow, thin cup of fine materials held together with spider and insect silk, usually dangling streamers of material on silk below nest. Slung hammock-like in fork of small branch in tree, usually over water.
Captures insects primarily by snatching them from leaves, especially from the undersides. Also hovers to glean insects and catches some in flight. Occasionally forages on ground.
Acadian Flycatcher numbers declined by about 13% between 1966 and 2014, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 4.5 million birds, with 100% breeding in the U.S. They rate an 11 out of 20 on the Continental Concern Score and are not on the 2014 State of the Birds Watch List, although they are a U.S.-Canada Stewardship species. These birds are vulnerable to forest fragmentation and loss of wintering habitat.
- Whitehead, D. R., and T. Taylor. 2002. Acadian Flycatcher (Empidonax virescens). In The Birds of North America, No. 614 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
- North American Bird Conservation Initiative, U.S. Committee. 2014. State of the Birds 2014 Report. U.S. Department of Interior, Washington, DC.
- Partners in Flight. 2012. Species assessment database.
- U.S. Department of the Interior, USGS Patuxent Wildlife Research Center. 2015. Longevity records of North American Birds.
- USGS Patuxent Wildlife Research Center. 2014. North American Breeding Bird Survey 1966–2014 Analysis