The Black Swift (Cypseloides niger) is sparsely distributed over wide portions of western North America from British Columbia and southwestern Alberta south to southern California and east to Colorado (A.O.U. 1983). Elsewhere its range includes Mexico, Central America south to Costa Rica, and the Greater Antilles. Within this range, it has a discontinuous distribution, with nests found on sea cliffs (Vrooman 1901), in sea caves (Legg 1956), behind mountain waterfalls (Smith 1928, Knorr 1962), on moist inland cliffs (Michael 1927), and in limestone caves (Davis 1964). The winter range of the migratory population in western North America is presumed to be southern Mexico (Friedmann et al. 1950).