Willow Flycatcher

Empidonax Traillii

Description:

"Generally indistinguishable from the Alder Flycatcher (E. ALNORUM), but tends to lack a conspicuous eye ring (Alder tends to have one), have a slightly longer bill, and is less green above (NGS 1983). Reliably distinguished from the Alder Flycatcher only by voice. Song is a sneezy "fitz-bew," with accent on the first syllable (Alder Flycatcher song is "rrree-BEEa" or "fee-bee-o" with accent on the second syllable) (Kaufman 1990, McCabe 1991). Breeding habitats of the two species differ somewhat, with Willow Flycatcher in more southern and western regions of North America and in more open habitats and Alder Flycatcher a more northern bird, generally breeding in shrub and alder thickets of boreal forests in the eastern U.S., Canada, and Alaska (McCabe 1991)." -Encyclopedia of Life

Habitat:

"BREEDING: Strongly tied to brushy areas of willow (SALIX spp.) and similar shrubs. Found in thickets, open second growth with brush, swamps, wetlands, streamsides, and open woodland (AOU 1983). Common in mountain meadows and along streams; also in brushy upland pastures (especially hawthorn) and orchards (NGS 1983). The presence of water (running water, pools, or saturated soils) and willow, alder (ALNUS spp), or other deciduous riparian shrubs are essential habitat elements (Sanders and Flett 1989, USDA Forest Service 1994). Occurs in both mesic and drier upland conditions, but apparently reaches highest densities on wet sites (Sedgwick and Knopf 1992). It is associated with dense riparian deciduous shrub cover separated by open areas, but large contiguous willow thickets without openings are typically avoided; it does not occur in dense tree cover but will use scattered trees for song and foraging perches and gleaning substrate (USDA Forest Service 1994). Habitat preferences may overlap with alder (EMPIDONAX ALNORUM) and least flycatchers (EMPIDONAX MINIMUS), to include deciduous woods and thickets, bottomlands and swamps (Griggs 1997). Foraging habitat may overlap with western flycatcher (EMPIDONAX DIFFICILIS; Frakes and Johnson 1982). In southwestern Ontario, generally occurs in more xeric upland sites, but in some areas uses boggy alder thickets, overlapping with alder flycatcher (Barlow and McGillivray 1983). In the Sierra Nevada of California, broad, flat meadows with willows and water are essential (Sanders and Flett 1989). In the Northern Rockies, is apparently restricted to riparian areas with adequate shrub cover (Hutto and Young 1999). In Colorado, males and females were found to select for different habitat attributes: female-selected nest sites typically had dense willows and were similar in patch size and bush height, male-selected song perch sites were characterized by large central shrubs and high variability in shrub size. On an increasing scale, breeding sites were respectively characterized by greater willow density, larger willow patches with smaller gaps, and greater percent willow coverage than non-willow coverage (Sedgwick and Knopf 1992). Southwestern willow flycatcher (E. T. EXTIMUS) breeds only in dense riparian vegetation near water or saturated soil. Habitat typically contains dense vegetation in the patch interior, often interspersed with small openings, sparser vegetation, or open water that creates a habitat mosaic of variable density. It nests in shrub and tree thickets 4-7 meters tall, with dense foliage 0-4 meters above the ground, and usually a high canopy coverage (USFWS 1995). The dominant plant species, size and shape of habitat patch, canopy structure and other habitat variables vary from monotypic to mixed-species stands and from simple to complex vegetation structures (Sogge et al. 1997). Habitats include dense high-elevation willow; native broadleaf shrubs and trees composed of willow, cottonwood (POPULUS spp.), boxelder (ACER NEGUNDO), ash (FRAXINUS spp.), alder, or buttonbush (CEPHALANTHUS OCCIDENTALIS); monotypic closed-canopy stands of tamarisk (TAMARIX spp.) or Russian olive (ELAEAGNUS ANGUSTIFOLIA); or a mix of native shrubs and exotic species (Sogge et al. 1997). Along the Virgin River, Utah, is restricted to shrub communities with shrub densities ranging from 70 percent to 100 percent (Whitmore 1977). NEST SITE: Nests primarily near slow streams, standing water or seeps, swampy thickets, especially of willow and buttonbush (AOU 1983, USDA Forest Service 1994), also dogwood (CORNUS spp.), elderberry, hawthorn, rose, tamarisk, and others; in fork or on horizontal limb of shrub, usually 1-3 meters above ground (see Harris 1991). In montane habitats, nests are usually in willows at least 2 meters high with foliage density of 50-70 percent and about 1 meter of cover above the nest (Sanders and Flett 1989). Also see Sedgwick and Knopf (1992) for information on nest sites and song perches in northcentral Colorado. Historically, southwestern willow flycatcher primarily in willows, buttonbush, and BACCHARIS spp. with a scattered cottonwood overstory. With changes in riparian plant communities, non-native tamarisk and Russian olive provide nesting habitat in some areas (Brown 1988, USFWS 1995). Along the Colorado in the Grand Canyon, for example, the flycatcher nests in tall tamarisk within 30 meters of water (Brown 1988, Sogge et al. 1997); however it is not known if nesting success differs in tamarisk compared to native vegetation (USFWS 1996). Where E. T. EXTIMUS nests in tamarisk, the tamarisk are usually taller (more than 5 meters) and denser (90 percent canopy closure) than in tamarisk-dominated areas where the flycatcher has been extirpated, and broadleaf shrubs may also be an important part of the community (Sogge et al. 1997). NON-BREEDING: Uses same types of habitats during migration and winter as breeding season (McCabe 1991). Occurs in dense scrub, deciduous broadleaf forest, streamside gallery forest, and freshwater wetlands (Rappole et al. 1995). In western Mexico and Central America, found in humid to semi-arid scrubby fields with hedges, fences woodland and edge, plantations; frequents low to mid-vegetation levels and often comes into open (Howell and Webb 1995)." -Encyclopedia of Life