South-western Canada (British Columbia) through western USA (east to southern Arizona) to north-western Mexico (north-western Baja California). Winter range highly unsettled, species occurring irregularly south to northern Sonora, south-east to Gulf Coast of USA, and even north to south-eastern Alaska; sporadically occurs much further east.
Population
Estimated population is 1,500,000 (2010).
Anna's Hummingbird (Calypte anna) [XC475167]
by Thomas Magarian from 2310 North Wygant Street, North Portland, Multnomah County, Oregon, United States (call)
Anna's Hummingbird (Calypte anna) [XC132220]
by Richard E. Webster from Portal, Arizona, United States (call)
Subspecies
Genus often merged into Archilochus, and both have sometimes been subsumed into Selasphorus. However, in morphology, vocalizations and displays, members of present genus stand apart from the Selasphorus-Archilochus assemblage. Alternatively, present genus sometimes merged into Mellisuga. Closely related to Costa's Hummingbird (Calypte costae), with which has hybridized. Also hybridizes with Blue-throated Hummingbird (Lampornis clemenciae). "Selasphorus floresii" usually reckoned to be hybrid of present species with Allen's Hummingbird (Selasphorus sasin). "Trochilus violajugulum" probably hybrid with Black-chinned Hummingbird (Archilochus alexandri).
BirdLife International Species Factsheet