Probable Occurrence of a Brown Bear (Ursus arctos) in Sonora, Mexico, in 1976

Abstract Measurements taken on the skull of a bear shot in northern Sonora, Mexico, in 1976 revealed that the skull is from a brown bear (Ursus arctos). The skull appears to be that of a juvenile (sex unknown) and, to our knowledge, represents only the fourth confirmed record of a brown bear from Sonora, although anecdotal accounts exist from the mid-1800s to early 1900s. The present record also establishes that brown bears, considered extirpated from Mexico since the 1960s, were present in Sonora within the past 30 years.