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).

Biogeographic Regions: nearctic (Native )

occurs (regularly, as a native taxon) in multiple nations

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: BREEDS: central California, southern Nevada, and southwestern Utah south to Santa Barbara Island, Baja California, and offshore islands, southern Arizona, west-central Mexico, southwestern New Mexico. WINTERS: southern California and southwestern Arizona south to Sinaloa, Mexico (Terres 1980, AOU 1983).

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).

Average mass: 3 g.

Average mass: 3.1 g.

Length: 9 cm

Weight: 3 grams

• Terrestrial

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).

Terrestrial Biomes: desert or dune ; chaparral ; forest ; scrub forest

Comments: Desert and semi-desert, arid brushy foothills, chaparral; in migration and winter also in adjacent mountains and in open meadows and gardens (AOU 1983). Most commonly in along canyons and washes when nesting. Nests in tree, shrub, vine, or cactus, often about 1.5 m from ground, sometimes near water, often far from it. In chaparral, nests often at break along edge or in tall bush.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Northern breeding populations move south for winter. Birds that breed in spring in Arizona migrate probably to Pacific coast to spend summer, return to southwestern Arizona in fall. Some possibly breed in California desert, then migrate to chaparral and breed again (Johnsgard 1983

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).

Comments: Feeds on nectar; also insects and spiders found in or near flowers. Nectar sources include: ocotillo, chuparosa, boxthorn, desert lavender, desert willow, sage, larkspur, etc.).

Males defend large territory, often 1-1.5 ha. Home range of breeding females "probably at least 1-km radius" (Baltosser and Scott 1996).

Range lifespan

Status: wild: 6 (high) years.

Average lifespan

Status: wild: 110 months.

The breeding season of C. costae varies with latitude and habitat, but always takes place between the months of January and May. Males and females do not pair, their only interaction is that of mating. Males arrive at breeding sites about one week before females and their flight displays begin 1-3 weeks before the first clutch is laid.

Nest-building is by the females and takes place immediately before a nesting attempt and is completed within 4-5 days. Nests are located in shrubs or trees and are usually found 1-2 m above the ground, this also varying with habitat. Nests usually have a diameter of about 3-5 cm and a height of 2-4 cm.

Clutches consist of two eggs. The first of the eggs is laid within 1-2 days of nest completion, the second is laid two days after the first. Incubation period is 15-18 days, hatching of the eggs is staggered. Mothers feed their young by regurgitation, this continues even after the birds have left the nest (in about 20-23 days) until they are able to fill their own nutritional needs (about one week). Young reach sexual maturity during first year and take part in the next breeding season. Two broods in one season are uncommon (Mallette 1990; Baltosser 1996).

Average time to hatching: 16 days.

Average eggs per season: 2.

Nesting season varies with location; begins in winter in some areas, over by late spring or early summer. Female incubates 2 eggs for 15-18 days. Young are tended by female, leave nest in 20-23 days.

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).

US Federal List: no special status

CITES: appendix ii

IUCN Red List of Threatened Species: least concern

United States

Rounded National Status Rank: N5B,N4N : N5B: Secure - Breeding, N4N: Apparently Secure - Nonbreeding

Rounded Global Status Rank: G5 - Secure

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).

Comments: Some authors merge Calypte in Archilochus (AOU 1983). Sometimes hybridizes with C. ANNA on Palos Verdes Peninsula, California. Also has hybridized with Archilochus alexandri.