Subspecies Selasphorus sasin sedentarius of Allen’s Hummingbird has been expanding its range in southern California since the 1960s. Nesting near Tijuana, Baja California, in 2014 and 2015 established the first nesting records for Mexico. The species is likely to expand farther into Mexico, and some local displacement of Anna’s Hummingbird (Calypte anna) may be expected.