Catharus
ustulatus
(Swainson's Thrush)
Physical
Description:
6 1/2-7 3/4" (17-20 cm).
Olive-brown above; buff eye-ring. buff
below with olive-brown
spotting on breast; flanks
darker.
Similar Species- Hermit Thrush and Veery
Song:
Upward
spiraling, flute-like song.
Distribution:
Breeds
from portions of Alaska and Canada, south to southern California, northern New
Mexico, northern Nebraska, eastern Montana, northern Minnesota, northern New
Engand, and Virginia. Winters in portions of South America, and in small numbers
to northern Mexico.
Habitat:
Found in dense, tall shrubbery, coniferous
woodlands (especailly
spruce), aspen/poplar forests, second growth, and willow and alder thickets.
During migration and in winter, also found in deciduous
forests, open woodlands,
humid lowland forests, scrub and brush (mostly mid-story or lower, but well
above ground). Most common in mountains. Preliminary results of northern Idaho
study indicated species was more abundant in continuous stands of old- growth
cedar/hemlock than in fragmented or selectively harvested stands. In southeastern
Idaho, species was strongly associated with cottonwood patches adjacent to natural
upland vegetation as opposed to agriculture, and preferred cottonwood forests
with willow subcanopies.
Diet:
Eats insects and other invertebrates,
small fruits, and seeds. frugivorous
in migration and during
winter.
Ecology:
Builds cup-shaped nest low in coniferous
tree or shrub. Solitary when not breeding, but found in loose flocks
in migration
(sometimes concentrated
in large numbers near fruiting trees and shrubs). Takes food from foliage. May
hover and drop to ground while foraging. Preliminary results of Idaho study
conducted in cottonwood forests found species was negatively associated with
grazed areas.
Conservation:
| Element Code: | ABPBJ18100 |
| Status: | Protected nongame species |
| Global Rank: | G5 |
| State Rank: | S5,NTMB |
| National Rank: | N5B |
Important
State References:
Saab, V.A. 1996. Influence of spatial
scale and land management on habitat use by breeding birds in cottonwood forests
of southeastern Idaho. Ph.D. Dissertation, Univ. Colorado, Boulder. 140pp.