Adults have a long, straight and very slender bill. The adult male, shown in the photo, has a white breast, rufous face, upperparts, flanks and tail and an orange-red neck patch (gorget). Some males may have some green on back and/or crown. The female has green upperparts, white underparts and a dark tail with white tips and rufous base.
Their breeding habitat is open areas and forest edges in western North America from southern Alaska to California. This bird nests further north than any other hummingbird. The female builds a nest in a protected location in a shrub or conifer. The male aggressively defends feeding locations within his territory. The same male may mate with several females.
These birds feed on nectar from flowers using a long extendable tongue or catch insects on the wing.
Because of their small size, they are vulnerable to insect-eating birds and animals. These birds require frequent feeding while active during the day and become torpid at night to conserve energy. This is the hummingbird most likely to stray into eastern North America.