The Gray Vireo (Vireo vicinior) winters primarily in Sonora and Baja California Sur (e.g., Barlow et al. 1999). There are scattered winter records from the Mexican states of Durango (Leukering and Bradley 1997), Coahuila (Howell and Webb 1995), and San Luis Potosí (Fry et al. 1996). North of the Mexican border, the only winter records are from the Big Bend area of Texas (Barlow and Wauer 1971) and southern, primarily southwestern Arizona, north to the Kofa Mountains (Phillips et al. 1964). There are no published winter records for Upper California.