Costa's hummingbird (Calypte costae) is a bird species in the hummingbird family Trochilidae.[3] It breeds in the arid region of the southwest United States and northwest Mexico; it winters in western Mexico.[3]
This species is small, as a mature adult grows to only 3–3.5 in (7.6–8.9 cm) in length, with a wingspan of 11 cm,[10] and an average weight of 3.05 g for males and 3.22 g for females.[3][11] The male has a mainly green back and flanks, a small black tail and wings, and patches of white below their gorgeted throat and tail. Its most distinguishing feature is its vibrant purple cap and throat with the throat feathers flaring out and back behind its head.[3] The female is not as distinct as the male, having grayish-green above with a white underbelly.[3]
The male Costa's hummingbird's courtship display is a spirited series of swoops and arcing dives, using an angle to the sun to display its violet extended gorget to prospective mates.[12] The male makes a high-speed dive pass or hover close to the female, perched on a nearby branch, and is accented by a high-pitched vibration that is produced by tail feathers. Separately, the male will perch and produce a high-pitched, scratch-like song.[3]
The female constructs a small cup-shaped nest out of plant fibers, down, and at times spider silk, coated with lichen to hold it together.[13] The nest is situated on a yucca stalk or tree limb. The female lays just two eggs, which are white in color, which she will incubate for 15 to 18 days before the young hatch. The young leave the nest after 20 to 23 days.
As common with hummingbird species, Costa's hummingbird feeds on flower nectar and small insects. While feeding in flight, a Costa's hummingbird may hover.
As with other hummingbird species, the Costa's hummingbird can slow its metabolism during cold nights when it enters a hibernation-like state known as torpor, with its heart rate and respiration slowing substantially.[3]
The IUCN describes them as of least concern. The population is stable and there are no known threats. They are found in at least one protected area.[14]
^ abGill, Frank; Donsker, David; Rasmussen, Pamela, eds. (January 2021). "Hummingbirds". IOC World Bird List Version 11.1. International Ornithologists' Union. Retrieved 1 March 2021.
