WatchList Species Account for Costa’s Hummingbird (Calypte costae)

Qualifies for the list as a Rare Yellow List Species

Photo: © William Zittrich

Costa’s Hummingbird inhabits the hot deserts and other xeric habitats in the southwestern U.S. and northwestern Mexico. Resident in much of its range, it withdraws from the northernmost and easternmost portions in winter and moves farther south along the Pacific coast of Mexico. In some areas it seems to be expanding its range. It is apparently common in much of its range but its coastal scrub habitat in California has been nearly eliminated. It has shown some ability in southern California to adapt to agriculture and urban development, nesting and wintering in orchards and coastal suburbs, but in general alteration of its natural habitats for agriculture and urban development is a major concern.

In particular the clearing of desert scrub and thorn forest for planing buffelgrass, an exotic species from South Africa, is a threat to the species; this grass is very fire-prone and repeated fires can eliminate the native plants on which the Costa’s depends. In Mexico, cattle-grazing in dry habitats is often intensive and degrades habitat for the birds. Though use of hummingbird feeders and the planting of exotic plants can be beneficial for hummingbirds in general, it may not be for the Costa’s in particular, as it draws other hummingbird species such as the Anna’s, to which Costa’s often loses interspecific confrontations. The species would benefit from the control of buffelgrass and the restoration of native habitats.