GORDON MITCHELL
Land Management Coordinator
There are a few different species of flycatchers that inhabit our area. One of those species is the Acadian flycatcher, (Empidonax virescens Vieillot). The generic name, Empidonax, is Greek for “gnat or mosquito master” or “king of gnats or mosquitoes.” The specific epithet, virescens, is Latin for “becoming green,” “to turn green” or “growing green.” This is due to their olive green back or their yellow-green underside.
The common name, flycatcher, is due to their ability to catch flying insects in mid-air. The common name, Acadian, was given because this bird was once thought to have inhabited Acadia (present-day New Brunswick and Nova Scotia), but this is well beyond their natural range.
Acadian flycatchers grow to about 6 inches long with a wingspan up to 8 inches. They only weigh about half an ounce. These birds have olive green backs, a faint olive-yellow breast, while their belly and flanks are yellow-green. Its olive gray wings have two prominent pale yellow wing bars. They have a narrow, pale yellow eye ring. The adults undergo two molts per year.
This species of flycatcher has the largest bill of its genus, which is long, broad and straight sided. They have black feet and legs, and a broad and long tail. You’re most likely to see them in moist, shady, mature, deciduous woodlands, especially those with American beech, maple and non-deciduous eastern hemlock trees. These birds are good indicators of a healthy forest.
NESTS
They’re a neo-tropical migrating species and normally arrive here in the north in May. Breeding season begins in June. They build their nests on forked branches of trees, anything from 3 feet to 50 feet above ground. The nests are made of fine twigs, grasses, bark strips and catkins, and are bound with spider or caterpillar webbing silk. The female birds build the nests, which are lined with finer grasses, hair, rootlets and plant down. They may hang a strip of vegetation from the nest, up to 2 feet, which may act as camouflage. Nesting season is usually May to August.
They lay between two and four eggs and may have two broods a year. Each egg is creamy white or buffy white with sparse dark brown or purple-brown spots and dots at the larger end. The egg is oval, elliptical, or sub-elliptical and is less than three-quarters of an inch long and is over half an inch wide. The shell is smooth and may be slightly glossy. These eggs are laid at daily intervals. The females alone incubate these eggs, which hatch in about 13-15 days.
The nestlings are born altricial and downy. Their down is sparse and white and their skin is pink. Their eyes open after four days. Both parents, especially the females, feed these nestlings. They fledge in about 12-18 days. The males may tend the fledglings for about 12 more days while the females tend to their second brood. Brown-headed cowbirds are known to parasitize the nests.