Geographic Variation in Body Size and Weight of Willow Ptarmigan

Abstract

Reports results of multiple range test comparisons of wing, tail and net body weight measurements of 2600 specimens collected in Alaska and adjacent Yukon Territory. Populations from different geographic areas showed statistically significant differences but uniformity within recognizable subspecies. Lagopus lagopus alascensis has the largest range in Alaska and occurs at least to Old Crow in the Yukon. L.l.albus occurs from central Yukon Territory eastward and south to northern British Columbia and west into Alaska in the upper Tanana valley and south of the Alaska Range to the Susitna River. L.l. alexandrae occupies the Alaska and Kenai Peninsulas and a narrow margin of the Gulf of Alaska coast south into British Columbia. L.l. murei is distributed on Kodiak Island, the Shumagins and the Aleutians from Unimak westward. The present distribution of these subspecies may be explained in part by their distribution at the time of the Wisconsin glaciation and their subsequent dispersal.