Scientific Name:
Empidonax minimus
Nest Type: Cup
Nest Location: Deciduous
trees, shrubs; 2-60', avg. 10-40'
Clutch Size: 3-6;
avg. 4
Food: Insects, berries
Foraging Guild:
Hover glean, hawks
The Least Flycatcher is
a summer resident in Minnesota and occurs throughout the wooded portions
of the state, except the south central and southwestern regions (Janssen
1987). It arrives in the state in late-April through mid-May after spending
the winter in Central America (Mexico to Panama) (Peterson 1980). It
begins its fall migration in early August and the last individuals depart
in early October. Its breeding distribution in North America covers
the northern and north central portions of the United States, except
the northwest, and the southern portions of eastern and central Canada
(Peterson 1980).
Like the Ovenbird and Red-eyed
Vireo, the Least Flycatcher is one of the most abundant birds of mature
forests in Minnesota (Roberts 1932). The Least Flycatcher is highly
associated with deciduous forests and, hence, the species was classified
as a hardwood dependent and mature forest species. In many situations
the species is found in deciduous woods with relatively open subcanopies
(Breckenridge 1955, Harrison 1975).
In northern Minnesota,
the species can be found in a wide range of habitat types including
both upland and lowland deciduous and coniferous forests (Hanowski and
Niemi 1991a, 1991b). Highest densities recorded for the species were
in mature maple in the Superior National Forest (about 5 to 6 pairs/40
acres) and mature birch in the Chippewa National Forest (Hanowski and
Niemi 1991a, 1991b). In northern Michigan, the species occurs in deciduous
and mixed forests and occasionally pole size jack pine (Brewer et al.
1991). In some situations, the species seems to form loose colonies
(Harrison 1975), sometimes resulting in very dense populations.
The Least Flycatcher places
its nest 2 to 12 m up in a tree and 4 eggs are usually laid (Harrison
1975). Incubation requires from 14 to 16 days. This species is an aerial
insectivore, therefore an open subcanopy in the forest allows the species
to efficiently forage (Breckenridge 1955).
Although Least Flycatchers
may occupy a wide range of habitats, they may be sensitive to habitat
fragmentation (Brewer et al. 1991). Large disturbances in forests in
northern Michigan resulted in a shift in territories to the interior
portions of the forest.. Territories were displaced within 200 m of
openings that were 40 acres (Dellasala and Rabe 1987). The species is
also susceptible to Brown-headed Cowbird parasitism (Briskie et al.
1990), which is often fatal to the host young because the incubation
period is longer than that of the cowbird.
The species has shown a
significant negative decline of about 3% per year in Minnesota over
the past 20 years based on breeding bird roadside surveys (Janssen 1990).
However, no significant nationwide declines were reported (Sauer and
Droege 1992).
