Acadian Flycatcher (Empidonax virescens)

Status: State Threatened (1989).

Occurrence: Uncommon summer resident southwest and southeast. Recent resident records come from the southern third of the state. Most reports are from Wyalusing State Park (Grant County), Baraboo Hills (Sauk County), Kettle Moraine State Forest (Fond du Lac County), and the Golden Lake Woods (Jefferson-Waukesha counties). There are most likely no more than 20 breeding populations remaining in the state.

Aid to ID: Small olive bird with a grayish throat, yellow eye rings, and two buffy or whitish wingbars. Acadians are slightly larger than the Least Flycatcher and have heavier bills. The best way to distinguish this bird from other Empidonax flycatchers is by their song: a loud "pit-eet."

Habitat: Require large tracts of mature mesic forest, with semi-open understory, and prefer forested streamsides and ravines. Breed in mesic, dry-mesic, and wet-mesic forests, as well as in hemlock, yellow birch, and white pine relics. In Kettle Moraine State Forest in southeastern Wisconsin, they have been found nesting in over-mature conifer plantations, with nests in red pine, white pine, Norway spruce, black cherry, box elder, common buckthorn, American elm, red oak, and white mulberry.

Food Habits: Mostly flies, but their diet also includes mosquitoes, small moths, flying ants and small beetles.

Natural History:

Breeding: Clutch size: 2-4 buffy eggs. Incubation: 13-14 days. Young fledge 13-15 days after hatching.
Nest: Occur in trees, saplings, and shrubs 5-20 feet above ground or water.

Management Considerations: Competition with northern mesic forest bird species, especially the least flycatcher, may be one barrier to range extension. Their distribution in the state is limited and relatively small, and they require large blocks of forest as nesting habitat. Any activity that destroys, reduces, or fragments extensive tracts of forest limits habitat availability for the Acadian flycatcher. Preservation of the Baraboo Hills, protecting against fragmentation and logging, will continue to provide an island of habitat suitable for this bird. The conifer plantations in southern Wisconsin provide suitable habitat as well. Management of these plantations, including thinning but not fragmenting, will provide potential habitat as well.