Swainsons thrush

Appearance

This species is 16–20 cm in length. The wingspan averages at 30 cm and the wing chord is 8.7–10.5 cm. The bill measures 1.5–1.9 cm in length and the tarsus is 2.5 to 3.1 cm long. This species' body mass can range from 23 to 45 g.

This thrush has the white-dark-white underwing pattern characteristic of ''Catharus'' thrushes. Adults are brown on the upperparts. The underparts are white with brown on the flanks; the breast is lighter brown with darker spots. They have pink legs and a light brown eye ring. Birds in the east are more olive-brown on the upperparts; western birds are more reddish brown.

Naming

The genus name ''Catharus'' comes from the Ancient Greek ''katharos'', "pure or clean" and refers to the plumage of the orange-billed nightingale-thrush ''C. aurantiirostris''. The specific ''ustuatus'' is Latin for "burnt", from ''urere'', "to burn".

Behavior

This bird's song is a hurried series of flute-like tones spiralling upwards.

Habitat

The breeding habitat of Swainson's thrush is coniferous woods with dense undergrowth across Canada, Alaska, and the northern United States; also, deciduous wooded areas on the Pacific coast of North America.

Food

They forage on the forest floor, also in trees. Swainson's thrushes mainly eat insects, fruits and berries. They make a cup nest on a horizontal tree branch.

Migration

These birds migrate to southern Mexico and as far south as Argentina. The coastal subspecies migrate down the Pacific coast of North America and winter from Mexico to Costa Rica, whereas the continental birds migrate eastwards within North America and then travel southwards via Florida to winter from Panama to Bolivia. Swainson's thrush is a very rare vagrant to western Europe. It has also occurred as a vagrant in northeast Asia.