Bill Lengths, Wintering Areas, and Taxonomy of North American Dunlins, Calidris alpina
MacLean SF and Holmes RT. 1971. Bill Lengths, Wintering Areas, and Taxonomy of North American Dunlins, Calidris alpina. The Auk. 88(4):893-901
The Dunlins that breed on arctic tundra of North America are separable into three distinct groups on the basis of bill length, with those of northern Alaska having shorter bills than those of western Alaska or north central Canada. The Dunlins of northern Alaska do not winter in North America but cross the Bering Straits to winter along the Pacific coast of Asia. The Dunlins of northeast Siberia, which also winter along the east Asian coast, have bills indistinguishable from those of northern Alaskan birds. These two populations should be included together in C. alpina sakhalina. The name C. a. pacifica should be restricted to the birds that breed in western Alaska and winter along the Pacific coast of North America. The name C. a. hudsonia, first used by Todd (1953), is applied to Dunlins that breed in north central Canada and winter along the east coast of North America. The selective pressures influencing the evolution of bill length include the size and kind of prey species available for exploitation and the presence or absence of ecologically similar species that might compete for the same food items. Geographic variation in these parameters is discussed.
- Type
- Journal Article
- Authors
- MacLean, Stephen; Holmes, Richard
- Units
- ARCN , BELA , CAKR , GAAR , KOVA , NOAT
- Keywords
- Anatomy, Arctic, Birds, Morphology, North Slope, Phylogenetic relationships, Range, Shorebirds, Wintering