Costa’s Hummingbird Nests in Sacramento County

Abstract

I report successful nesting by a female Costa’s Hummingbird (Calypte costae) in 2025 in my residential yard, a first record for Sacramento County, California. The nest location is outside of the species’ known breeding range. Based on the lack of a male Costa’s Hummingbird seen in the area during the time when mating should have occurred, it appears possible that the female hybridized with a male Anna’s Hummingbird (Calypte anna).