Will breed in dry habitats, although favors wet deciduous forests, such as swamps, riverside woods, floodplain forest, and streamside woods (Fussell 1994, Hamel 1992, Kaufman 1996, Potter et al 1980, Simpson 1992). Also prefers forests with a moderate understory (Hamel 1992).

Nest is usually in a deciduous tree or shrub and averages 13 ft. above ground (Kaufman 1996). If in a tree, the nest is generally in lower branches and far out on the limb from the trunk (Harrison 1975). The hammock-like nest is placed between two horizontal branches or on a fork in the limb (Ehrlich et al 1988, Kaufman 1996, Potter et al 1980). Construction materials used for the nest include plant stems and fibers, tendrils, catkins, and lined with grass, rootlets, plant down, and spider webs (Harrison 1975). Potter et al (1975) describes the Acadian FlycatcherÆs nest near the coastal section as constructed of Spanish moss, in the mountains made up of mostly lichen or hemlock twigs, and formed of fine grasses and rootlets everywhere else in the state. This flycatcher forages from a perch in the middle level of the forest, mainly hawking insects, although will glean from foliage and twigs as well (Kaufman 1996).

NATURE SERVE GLOBAL HABITAT COMMENTS:

BREEDING: Key habitat requirements are moist deciduous forests with a moderate understory, generally near a stream (Hamel et al. 1982). Humid deciduous forest (primarily mature), woodland, shaded ravines, floodplain forest, river swamps, hammocks and cypress bays of south, thickets, second growth, plantations. Requires a high dense canopy and an open understory (Bushman and Therres 1988). Tends to be scarce or absent in small forest tracts, unless the tract is near a larger forested area (see Bushman and Therres 1988). Floodplain forests must be more than 400-500 feet wide before they become suitable for nesting (Peterjohn and Rice 1991).

Nests in tree in horizontal twig fork toward end of lower branch, often over water, ravine, or other clearing, usually at a height of about 2-9 m. Usually nests on a lower branch, far out from trunk; usually shaded by leafy branches. Average nest characteristics have been measured by D. R. Whitehead and G. M. Greenberg (pers. comms.) for forest interior sites in Indiana: dbh of nest tree - 12.46 cm; nest height - 5.67 m; nest tree height - 14.96 m; distance from bole - 4.37 m; distance to watercourse - 20.74 m; and slope - 18.80 degrees. Bent (1942) describes it as a bird of the forest: it is found in cypress swamps, in heavily wooded bottomlands, and in the depths of wooded ravines. Of Wisconsin, Bent (1942) writes 'The essential requirement of the Acadian Flycatcher appears to be a large tract of undisturbed timber. The typical habitat is a deep, well-wooded ravine having a rocky stream bed, which is usually dry. It may also be looked for in the heavy timber of the river bottoms and in tamarack swamps in the southern portion of the state.' Conner and Adkisson (1975) found it in mature forest with a basal area of 90 ft squared/acre (21 m squared/ha) (Bushman and Therres 1988).

Vegetation types for the southeastern U.S. from Hanel et al. (1982), in order of suitability, are: oak-gum-cypress and elm-ash-cottonwood are listed as optimal habitat at both the sapling-poletimber, and sawtimber stages; cove hardwoods are listed as suitable at the sapling-poletimber stage and optimal at the sawtimber stage; southern mixed mesic hardwoods are listed as only marginal at the sapling-poletimber stage and optimal at the sawtimber stage; bay swamp-pocosin, oak-hickory, and white pine-hemlock are all listed as only marginal at the sapling-poletimber stage and suitable at the sawtimber stage; mixed pine-hardwood is listed as only marginal at both the sapling-poletimber and sawtimber stages. In all cases, midstory and overstory canopy are used for all activities (feeding/foraging, nesting, perching, roosting, and singing) and dead trees or limbs are used for feeding/foraging and singing. Requires snags for foraging with a minimum dbh of 6 in (15 cm) and exposed perches in the midstory (Hamel et al. 1982). D. R. Whitehead and G. M. Greenberg (pers. comms.) have observed foraging on all types of trees, but usually not snags because they sometimes pick insects off leaves. Data on habitat selection are also given by Hespenheide (1971); where Acadian Flycatchers overlap with Least Flycatchers (EMPIDONAX MINIMUS), the preferred habitat of Acadians has apparently changed in accordance with predictions of competitive effect based on overlap data alone.

MIGRATION: Open scrub and young second growth to primary and secondary forest.