Swainson’s Thrush

Catharus ustulatus

The Swainson’s Thrush is sometimes called Olive-Backed Thrush. They breed in coniferous woods with dense undergrowth across Canada, Alaska and the northern United States, also deciduous wooded areas on the Pacific coast of North America. These birds spend winters in Mexico, Central and South America.

Thrushes in the genus catharus are more difficult to distinguish than some other genera. This is especially true of the Hermit, Gray-Cheeked and the Swainson’s Thrushes. If seen in the shadows, where these birds often are, the subtle variations are hard to pick up. One distinguishing feature that sets the Swainson’s Thrush apart from the others is the appearance of so-called “spectacles” that their eye-ring and patch between the eye and the bill make.

Science recognises six subspecies of Swainson’s Thrush. These are split into two groups: the “Russet-Backed” and the “Olive-Backed”. In the Russet group are three subspecies. C. u. ustulatus breeds in southeast Alaska to northern California and winters in western Mexico. C. u. oedicus breeds in northern California west of the Cascade and Sierra-Nevada mountains, and south to southern California. The winter in western Mexico and possibly in Central America. C. u. phillipsi breeds in British Columbia on Queen Charlotte Island and winters in western Mexico.

There are also three members of the Olive-Backed group. C. u. swainsoni breeds in the northern forest of Canada from British Columbia to Nova Scotia and in the northern tier of the USA. These birds winter in northern and central South America. C. u. incanus breeds in east Alaska, the Yukon Territory, British Columbia and Alberta. These birds winter in South America in Colombia and Peru. C. u. appalachiensis breeds in the northern Appalachian range from New Hampshire and south. This group winters in South America in Colombia.

Click map markers to reveal further information