Calypte costae
Costa's hummingbird
(Also: Costa's hummingbird)

Calypte costae is commonly found in the far west region of the United States and Mexico with a northern limit of central California and a southern limit of central Mexico. However, there have been reports of C. costae in Alaska, Kansas, and the southern tip of Mexico (Baltosser 1989, 1996).

Calypte costae is found in primarily desert-like habitats. An arid climate is preferred, with plants such as the Joshua tree (Yucca brevifolia) and cholla cactus (Opuntia acanthocarpa). However, when nectar is in short supply, C. costae will leave the desert in search of food.(Baltosser 1989, 1996; Mallette 1990).

With a length of 7.62 cm, C. costae is the second smallest North American species of hummingbird. The back and head of C. costae are an iridescent green. Adult males possess a flared throat patch, both this gorget and their crown are a brilliant metallic purple. Adult females are recognizable by a small tuft of violet feathers in the center of the throat, however, only about half possess this; the throats of the remainder are completely white. In both sexes, the bill is dull black, the iris of the eye is dark brown to black, and the legs and feet are also dark brown to black. Young C. costae gain mature appearance by the age of one year (Mallette 1990; Baltosser 1996).

Calypte costae is a mobile species. Solitary during most of its life, it migrates when nectar becomes depleted or temperatures become intolerable. Females vocalize frequently, indicating food sources, prey, enemies, and mating rituals. Males seldom call, except when alarmed or during a courtship display. Both sexes' calls are very high pitched and distinctive. Offensive behavior towards predators (e.g. snakes, birds, humans) includes a rapid plunge at the predator and elaborate flight displays.

During the breeding season, males use an aerial display of broad loops to self-advertise to females. This display is accompanied by a whistle each time the male dives from the top of its loop. Females observe this display and often respond with a burst of twitters. If receptive, the female becomes the object of short darting flights by the male, ending in copulation (Baltosser 1996).

Calypte costae is an omnivore, though it feeds mainly on nectar from flowers. The hummingbird recieves this nectar from traditional hummingbird flowers (these plants produce 2-5 mg sucrose-equivalent sugar/flower/day), such as the desert honeysuckle (Anisacanthus thurberi) and the barestem larkspur (Delphinium scaposum), and also from tiny desert lavender flowers (Hyptis emoryi) and huge saguaro flowers (Cereus giganteus). To satisfy protein needs (about 4.5 mg nitrogen/day), C. costae also feeds on small insects by fly-catching or gleaning from leaves, branches, or tree trunks (Baltosser 1996).

Unknown, if any.

Hummingbirds aid in the pollination of several species of plants. Calypte costae, in particular, provides a method of pollination for various desert plants and cacti (Baltosser 1996).

The most dangerous threat facing C. costae today is the destruction of its native habitat. Humans have all but eliminated the hummingbird's breeding ground (coastal scrub) with urban and residential development. Agriculture, exotic grasses, and cattle-grazing have also depleted many sources of food for C. costae. Hummingbird feeders and exotic plants, an accepted solution to the lack of nectar available, do not provide enough nutrition to C. costae, as it is often outcompeted by larger hummingbird species (Baltosser 1996).

Calypte costae prefers red flowers.

When making the nest, female C. costae will often use spider webs to secure the materials together.

Calypte costae takes its name from a French nobleman, Louis Marie Pantaleon Costa.

(Mallette 1990; Indianapolis Zoo 2001)