The Red-shouldered Hawk (Buteo lineatus) is a polytypic species with a disjunct North American breeding range. Four or five subspecies in two distinct groups are recognized (AOU 1957, Stresemann and Amadon 1979, Wheeler 2003a). Three or four of these (in one group) breed in the eastern half of North America, whereas one well-marked subspecies, B. l. elegans, resides along the Pacific coast, primarily in California, but also in southern Oregon, western Nevada, western Arizona, and Baja California (Wilbur 1973, Glinski 1982, 1998, Howell and Webb 1995, Marshall et al. 2003, Wheeler 2003b). The nominate subspecies, B. l. lineatus, is migratory, breeding primarily in the northeastern United States and migrating as far south as Florida and central Mexico (Stresemann and Amadon 1979, Howell and Webb 1995, Wheeler 2003b). Three other resident subspecies from the southeastern United States and northern Mexico have been recognized, texanus, alleni, and extimus; however, Wheeler (2003a) synonymized texanus with alleni.