Habitat
The Willow Flycatcher breeds in a variety of shrubby habitats across North America.
Its habitat preferences are well documented for eastern North America (Stein 1963,
Walkinshaw 1966, Barlow and McGillivray 1983), the southwestern United States
(Sedgwick and Knopf 1992, Sogge et al. 1997) and the Pacific Northwest
(King 1955, Stein 1963, Campbell et al. 1997). Typically, upland sites
supporting a mixture of shrubs including willow (Salix spp.), hawthorn
(Crataegus spp.) and rose (Rosa spp.) are preferred. Alder Flycatchers
are commonly found in more mesic sites but Willow Flycatchers are found in riparian
shrubs in the southwestern United States (Sogge et al. 1997) and in willow
swales in British Columbia (Campbell et al. 1997) and Ontario (Barlow and
McGillivray 1983). In Alberta the Willow Flycatcher has historically occupied
relatively dry, upland, shrub-dominated sites (Semenchuk 1992, McGillivray and
Semenchuk 1998). In our 1999 assessment of Willow Flycatchers in Alberta, they
were found in the mesic habitats typical of Alder Flycatchers (Semenchuk 1992).
The survey provided no evidence that dry, upland habitats supported any Willow
Flycatchers.
 |
| Figure 2. Willow Flycatcher habitat north of Hunter Valley.
Note water is abundant and willow bushes 1-2 m tall. |
We performed detailed habitat assessments on 26 sites supporting Willow Flycatchers
in Alberta along the eastern slopes. The sites are in low-lying areas where water
tends to collect such as valley bottoms, lake edges, or ditches along roads (Fig.2).
Habitat patches that support breeding pairs range from 2-50 ha in size with the
mean being 8.4 ha. Willow bushes, of course, are an integral part of the bird's
habitat. The average height of the willows in territories of Willow Flycatchers
is about 2 m. The willow bushes are often densely packed but the habitats are
patchy with water or grassy areas interspersed among the willow patches. The majority
of territories contain open water while the rest of the sites had water nearby.
Standing water is typical of willow sites although some sites contained moving
water. The average size of the largest patch of open water on each site is 0.35
ha with the maximum size being 1.5 ha.
 |
| Figure 3. Spruce trees and snags are common features of
many Willow Flycatcher sites. They are used for perching, foraging and display. |
A common feature of most Willow Flycatcher territories in Alberta is the presence
of a few to many spruce trees or snags that rise above the canopy amid the willow
patch (Fig. 3). These trees are used for perching and as launching points for
display and foraging flights.
Go
to Conservation biology