Return of Bird of the Week: Gray-cheeked Thrush

Gray-cheeked Thrush, Denali Highway, Alaska

This is another Catharus thrush, wintering in South America and breeding in the taiga and low Arctic shrub thickets from Newfoundland to the Seward Peninsula in Alaska. It has an unusual migration route; all the birds, even those breeding in far western Alaska and eastern Siberia, move through the eastern half of the Lower 48. Stateside, Gray-cheeked Thrushes are almost unknown west the the Dakotas and Nebraska.

Bicknell’s Thrush was split from this species in the early 1990s. Most of the research on “Gray-cheeked Thrushes” turned out to have been done on became Bicknell’s Thrushes, and as a result Gray-cheeked are among the more poorly studied and least known of the common North American passerines.

Gray-cheeked Thrush, Denali Highway, Alaska

This species is slightly larger than its cousins, the Swainson Thrush and the Hermit Thrush, and is identified by its very faint eye ring, triangle-spotted chest and plain white belly. The gray cheek that gives the species its name is not a reliable field mark.

Most nests seem to be built in crotches of branches of willow or alder shrubs, but some are placed instead on horizontal or slanting trunks of fallen trees, atop broken-off stubs or rotting stumps and horizontal spruce branches. The nest is a compact, well-built structure with deep cup. Information about breeding is sketchy, but the reports say there are usually four eggs, incubated for perhaps twelve days. The hatchlings fledge in maybe thirteen days, and are fed by their parents for perhaps another eight days.

Gray-cheeked Thrush, Steese Highway, Alaska

There are suggestions in the literature that Gray-cheeked Thrushes are incidental beneficiaries of climate change, at least in their breeding range. As the boreal forest warms, the shrubbery line is moving north, shrubbery that is the favored habitat of the species. In its winter range in the northern half of South America, things aren’s so good. Habitat loss there may be impacting the world populations. In Newfoundland, Gray-cheeked populations are in dramatic decline; in Alaska it’s a slower decline but still concerning. Data for Canada are ambiguous. Despite those trends, world-wide the IUCN classifies them as a species of Least Concern.

For more bird photographs, please visit WC’s bird photo site, Frozen Feather Images