On 15 September 1990 we collected a Red-breasted Nuthatch (Sitta canadensis) at Rancho Casa Verde, western slope of the Sierra Juárez, east of Ensenada, Baja California, México (32° 04' N, 116° 05' W; altitude 1370 m). The specimen, an adult male of 113 mm total length (Figure 1), was taken climbing in Pinus jeffreyi, and represents the first mainland record of this species from Baja California.
The fall of 1990 saw a large incursion of the Red-breasted Nuthatch in California, just north of the U.S.A.–Mexico international boundary (Rich Stallcup pers. comm.), and is probable that our collected bird in mainland Baja California was in transit rather than a breeder or resident.