Costa's Hummingbird occupies hot deserts and other xeric habitats west of the Continental Divide and south of the Great Basin: "the dry desert hummingbird par excellence " (Phillips et al. 1964: 62). Even though Sonoran desert scrub is the heart of its range, it is not exclusively a desert species; it leaves the deserts of Arizona and southern California in summer. The restriction of Costa's Hummingbird to the Far West is due probably to a Pacific slope origin and to Sonoran Desert climate, which permits flowering in winter and spring.
Although partial to xeric habitats, Costa's Hummingbird is no less attracted to nectar than are other hummingbirds. It forages for small arthropods in typical hummingbird fashion¿by fly-catching. Nectar supplies vary greatly during the 6 to 9 months each year that this species inhabits desert scrub in Arizona and California. Individuals are common only when nectar plants are flowering well, yet rarely are they common enough during peak flowering to harvest a majority of chuparosa (Justicia californica) or ocotillo (Fouquieria splendens) nectar.
Help author an account about this species from a Neotropical perspective.