Associated Species: Other species that may use habitat in a similar way and/or respond similarly to threats, management, and conservation activities include Turkey Vulture, Golden Eagle, Peregrine Falcon, Common Raven, and Canyon Wren.

Distribution: White-throated Swifts breed from northern Idaho south to the central California coast and into Baja, and from north-central Montana south into Central America. They nest in cliff/rock habitat throughout Physiographic Area 87 in Colorado.

Habitat Requirements: These swifts require cliffs, where colonies build their nests in rock crevices. White-throated Swifts forage on the wing over many different habitats, staying within a few miles of their nests.

Ecology: Birds begin arriving in Colorado in April and begin nest activities in June. Most young leave the nest by July, but some nests remain active into August. Most birds leave the state by the end of September. In the fall, birds from Colorado and other northern areas retreat to more southerly portions of the range, but we do not know precisely where Colorado's birds winter. Their diet consists of aerial insects, including flies, beetles, bees, and flying ants. The inaccessibility of their nest sites and their tremendous flight speed make White-throated Swifts difficult to study; consequently, comparatively little is known about them beyond basic natural history facts.

Management Issues and Conservation Recommendations: The causes for the observed population declines are not known, but could be related to disturbance at nest sites, degradation of wintering habitat, or pesticide exposure; elevated levels of pesticides were found in specimens collected in the 1970s. Determine the role of pesticides, if any, in their population declines.

Nest sites are often used year after year. Enforce seasonal closures at known nest sites to minimize nest-site disturbance.

Status and Reasons for Concern: This species has a moderately high conservation need throughout its range, along with high representation in the physiographic area and a declining population. Within Physiographic Area 87, BBS data show a statistically significant annual rate of decline between 1969 and 1996 (P = 0.10; n = 21 routes). An even more disconcerting trend is evident in the BBS pinyon-juniper stratum (84) during 1966-1996, where this species exhibited a significant annual rate of decline (P = 0.08; n = 18 routes). White-throated Swifts were present on an average of 32.87% (SE = 6.83) of the BBS routes run in Physiographic Area 87 in Colorado during 1988-1997, at an average abundance of 4.24 (SE = 1.06) individuals per route. The mean number of routes run each year was 11.4 (SE = 1.55). This species is monitored by MCB with tracking transects.

Biological Objective: Increase the species' distribution and abundance, based upon results from the BBS and MCB monitoring programs.

Selected References: Andrews and Righter 1992, Bradbury 1918, Kingery 1998.