Introduction

Rosy-finches in general are extreme-environment specialists, and the Gray-crowned Rosy-Finch is no exception. Although descending to lower elevations in autumn and winter, even to the fringes of the western plains in the north, in summer they are found only at craggy breeding sites in the Brooks, Rocky, Cascade, and Sierra Nevada mountain ranges, as well as similar austere habitats on the Aleutian and Pribilof Islands. They are possibly the highest-altitude breeding bird in North America. On long wings, these handsome brown and pink birds appear to navigate easily through high winds and blowing snow when most other species have sought shelter at lower elevations. Their buzzy Chew Call is often one of the few signs of life on alpine ice fields, wind-swept scree slopes, avalanche chutes, and rocky plateaus.

Perhaps because of its remote breeding sites, which allow little contact with humans, the Gray-crowned Rosy-Finch seems almost fearless. On breeding grounds, foraging birds can be approached to within 1–2 m, and the surest way to catch them is to herd them into mist-nets. After banding, individuals often alight less than a meter away, then pick at their band and preen for several minutes.

Although all forms of rosy-finches in North American were merged with the Asian Rosy-Finch (Leucosticte arctoa) into a single species from 1983 to 1993, justification for this was viewed as insufficient (Am. Ornithol. Union 1983, 1993) and contradicted by genetic, biochemical, and morphological evidence with respect to Asian versus North American taxa (Sibley and Monroe 1990, Zink et al. 1995). Once again, 3 distinct North American species of rosy-finch are recognized, Gray-crowned Rosy-Finch being the most widely distributed and abundant among them.

Observation of rosy-finches on their breeding grounds requires travel to remote destinations and/or challenging mountaineering. Thus, many aspects of their breeding biology are relatively understudied. Despite these challenges, key studies on a few populations in the Aleutian Islands (Shreeve 1977, 1980a; Johnson 1983), the Rocky Mountains of Montana (Johnson 1965), and Sierra Nevada of California (Twining 1938a, 1938b, 1940) have revealed fascinating adaptations of this species to its barren home. Because the subspecies of rosy-finches vary in several aspects of behavior (e.g., degree and nature of migration) as well as the type of extreme environment in which they live (alpine versus arctic maritime habitats) the challenge of studying this species should continue to be rewarding for some time to come.