Adult female ... and twitters distinct from Anna’s. Costa’s generally plainer on throat and underparts, without dusky throat spotting. See black-chinned hummingbird.

The film "Hummingbird" explores the fascinating world of hummingbirds, detailing their various species, unique flight mechanics, and vibrant plumage. It follows the life cycle of the Calypte Anna ...

Female Allen’s and rufous hummingbirds, however, are nearly impossible to distinguish in the field. Anna’s hummingbirds are present year-round in the Bay Area. (Photo by Mick Thompson ...

Female hummingbirds use the finest plant fibers ... “A hummingbird nesting in your area in January would be either Anna’s hummingbird or Allen’s hummingbird. Reuse of nests is an uncommon ...