Most likely to nest along river valleys with steep unvegetated cliffs (Andres 1999b). In other areas, nests on ledges or shallow caves in steep rock faces and canyons, usually near of behind waterfalls and in sea caves (AOU 1998). Presence of water, high relief, inaccessibility to ground-dwelling predators, darkness, and unobstructed flyways were found to be important nest site characteristics in a study in the Rockies (Knorr 1961). Forages over open areas and forested areas in montane habitats (AOU 1998) and in Alaska observed foraging over mainland rivers, lakes, shores and associated wetlands (Baluss 2006).
Andres, B.A. 1999b. Landbird conservation plan for Alaska biogeographic regions. Version 1.0. Boreal Partners in Flight Working Group. October 1999. USFWS, Anchorage, Alaska.
AOU. 1998. Check-list of North American birds. Seventh edition. American Ornithologists’ Union, Washington, D.C. 829 pp.
Baluss, G. 2006. Black Swift distribution in Alaska; 2005 annual summary of landbird projects for Boreal Partners in Flight (C. Harwood, ed.), Boreal Partners in Flight, Anchorage, AK.
Knorr, O. A. 1961. The geographical and ecological distribution of the black swift in Colorado. Wilson Bulletin 73:155-170.