Geographic variation in body size of American mink ( Mustela vison ) / Variation géographique de la taille du corps chez le vison d'Amérique ( Mustela vison )

AbstractSpatial variation in 26 morphological characters of American mink ( Mustela vison ) from 35 localities in North America was investigated using univariate and multivariate statistical analyses. Localities were chosen based on watersheds, and it was hypothesized that high levels of gene flow in minks would prevent partitioning of body size variation within watersheds. All 26 characters in males and 25 of 26 in females exhibited significant interlocality variation. The patterns of variation in body size resulting from principal components analysis indicated that, for both sexes, minks were largest in Alaska, Manitoba, and Alberta; smallest minks were found in Florida and Quebec. There did not appear to be a relationship between body size and geographic proximity. Environmental factors collectively were found to be related to body size, although individual variables were not typically significant. Of 16 environmental variables examined, only longitude was correlated with body size in both sexes, with largest minks in the west and smallest in the east. Latitude was also correlated with body size in females. It was concluded that variation in body size of mink was likely the result of more than one factor that includes both biotic and abiotic features.