Evolutionary and Taxonomic Relationships among North American Arid-Land Foxes

Abstract

Relationships among nominal taxa of North American arid-land foxes were assessed by morphometric and protein-electrophoretic methods. Morphometric data distinguished between the kit fox (Vulpes macrotis) of the Southwest and the swift fox (V. velox) of the Great Plains but not among nominal subspecies of the two foxes. It was uncertain from the morphometric data whether the two foxes should be regarded as species or subspecies. Genic divergence was negligible, with two subspecies of the kit fox more similar genetically to the swift fox than to two other subspecies of the kit fox. We conclude, based on the genic data, that all arid-land foxes in North America pertain to one species, Vulpes velox. Based on the morphometric data, we conclude that two subspecies, V. v. velox and V. v. macrotis, should be recognized.