Bird of the Week

17
Photo courtesy Ben Bailey

This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the gray-crowned rosy-finch.

Spanning three species in North America, rosy-finches are known for their semi-obscurity, in part because they tend to breed in more remote locations at higher elevations than most songbirds and thus often go undetected. These birds seek out talus fields, cliffsides and often overlooked barren hillsides and rock piles above tree line to build their nests. Thankfully, in winter we get the opportunity to witness these magnificently colored birds (often in larger flocks), as they come downslope into valleys and lower elevations to source seed crops from grasses and wild mustard, occasionally turning up in flocks at feeders to glean sunflower seeds off the snow. Other food sources include a heavy insect diet during the warmer months, especially when feeding young.

Unlike the more regionally centric brown-capped rosy-finch, the gray-crowned breeds at northern latitudes from British Columbia through the Yukon Territory to northern Alaska. In fact, the gray-crowned rosy-finch has been observed nesting alongside glaciers on the upper flanks of Denali in Alaska. During courtship, males approach prospect mates with wobbles, crouches and wing displays, singing all the while. Females locate nesting locations in the rocks to build cup-shaped nests lined with grasses, lichens and root masses, among other components, to support the rearing of one brood per year. In winter, they migrate as far south as the southern Rockies west through the high deserts of Nevada and California.

These birds are often described as “chunky” for finches and are largely brown from the upper breast through the cheek, but at maturity have distinctive gray heads with a black forehead and throat. The “rosy” attribute refers to the almost-salmon coloration on the flanks and upper leading portions of the wing that in flight grace one with a delightful and noticeable pink flash of color. The coloration in the beak shifts from a black color during breeding season to a duller yellow color for the remainder of the year. Juvenile birds are largely brown, as the pink markings and gray head don’t develop until the second year. Songs and calls resemble a series of repetitive chews and cheeps.

Though breeding grounds in the high country have been largely unaffected by habitat degradation, the repercussions inherent in a warming climate may pose challenges to this species in the coming decades.

For information on events, visit www.weminucheaudubon.org and www.facebook.com/weminucheaudubon/.