- Empidonax virescens
Identification
Length 13-14.5 cm, weight 12.2-14 g -- One of the larger Empidonax flycatchers, and the one in North America having the largest bill Adult in spring plumage
- Olive-green upperparts with two white wingbars and white tertial fringes
- Underparts white with a hint of yellow
- Long primary projection
- Narrow but obvious pale eye ring
- Bill slender, broad-based, pinkish-yellow below, dark above
Molts in late summer on breeding grounds; fall migrants in fresh plumage
- Wingbars yellowish to buffy
- Underside much more yellow than spring, but less than juvenile
Juveniles
- Wingbars buffy and tertial and other fringes yellow
- Underside more yellow than any other plumage
- Most feathers in crown with buff tip, and feather tips yellow to buff also on body
Similar Species
Yellow-bellied and Least Flycatcher are smaller; Yellow-bellied also darker yellow-brown beneath and smaller billed, and Least grayer above and whiter below and has a smaller bill. Alder and Willow Flycatchers are browner above and whiter below, and with less obvious eye rings. Western Empidonax flycatchers have darker lower mandibles, and either whiter underparts (Gray and Dusky Flycatchers), darker breasts (Hammond's Flycatcher), or oval eye rings (Pacific Slope and Cordilleran Flycatchers) as well as only rarely occurring in the same areas on passage and the winter grounds. Pewees are obviously larger, browner above, whiter below and lack obvious eye rings[1].
Distribution
Breeds in the eastern United States, and just into the extreme south of Canada in southwestern Ontario. In the US, west to southeastern South Dakota, central Kansas and southern Texas, east to southern New England, and south to the Gulf Coast, and central Florida. Most abundant in Virginia and West Virginia[2]. Migrates mainly through eastern Mexico; scarce on the western Caribbean islands. Winters in Central America and northern South America, from Nicaragua southwest to Ecuador and east to Venezuela.
Listed as Endangered in Canada, with only around 25-75 pairs annually, all close to Lake Erie[3].
A very rare vagrant west of the breeding range, with records from New Mexico and British Columbia.
Taxonomy
This is a monotypic species.
Habitat
Breeds in mature moist deciduous or mixed forests of preferably over 40 hectares size with shrubby understory, often close to running water. Less common in, but will use, conifer plantations. In smaller, fragmented forests suffers high levels of nest parasitism by Brown-headed Cowbirds.
Behaviour
The diet includes insects which they catch by hawking and gleaning, and some berries and seeds.
Vocalisation
The song is a loud peet-sa. The call is a soft peet.
References
- www.mbr-pwrc.usgs.gov
- cornell.edu
- Ontario birds: Acadian flycatcher
