Costa's Hummingbird

Costa's Hummingbird is a small hummingbird of arid desert regions in the southwestern United States and northwestern Mexico, well adapted to hot, dry scrub habitat. The male's gorget is especially dramatic, extending well past the throat into elongated side plumes that give it a distinctive flared, mustache-like shape when displayed.

The male's gorget is a brilliant iridescent violet to purple, extending into long pointed feathers that flare outward past the sides of the throat, a shape unlike the rounder gorgets of many other hummingbirds. The crown may also show some violet iridescence. The back is green and the underparts whitish-grey. Females lack the violet gorget, showing a plain whitish throat, green back, and pale underparts, requiring more care to separate from other female desert hummingbirds. Compare structurally with Black-chinned Hummingbird females, which are similarly plain but lack Costa's slightly shorter tail proportions and different wingbeat sound in flight.

Males display the elongated violet-purple gorget and crown iridescence described above; females are plain green-backed and whitish below without a colored throat patch. Juveniles resemble females, with young males developing gorget feathers gradually through their first year. Feather freshness after molt affects how vividly the male's throat iridescence appears.

Found in arid desert scrub, chaparral, and dry washes across the southwestern United States, including California, Arizona, and Nevada, extending into northwestern Mexico. Some populations are resident while others shift seasonally, moving to track flowering desert plants.

Feeds on nectar from desert-flowering plants and small insects, well suited to hot, dry conditions. Males perform a steep diving display flight accompanied by a high, whistling sound during courtship. Its call includes thin, high-pitched notes. Nests are tiny cups of plant down, often placed in desert shrubs or small trees, timed to coincide with seasonal desert bloom.