North America after the breeding season. It remains unclear where most of the birds spend the winter, although some of the birds have been tracked as far south as Brazil. A study published in 2012 tagged four birds breeding in Colorado with a light level geolocator and found that the birds wintered in the lowland rainforest of western Brazil. Some of the birds in the West Indies appear to be permanent residents. They are late spring migrants into the breeding range, with Colorado breeders not arriving until the very end of May into June. Large flocks of migrants are occasionally seen spring and fall, but only very rarely far south of the U.S. breeding range. Behavior and ecology Food and feeding American black swifts live on the wing, foraging in flight. They eat flying insects, primarily flying ants and beetles, often foraging in small groups. Breeding Their breeding habitat is frequently associated with water. The birds most often nest on high cliff faces, either above the ocean surf or behind or next to waterfalls. The nest is made of twigs and moss glued together with mud. They will also use ferns and seaweed if available. The clutch size is one egg, with incubation lasting 23–27 days. Newly hatched young are probably fed multiple times a day, but older nestlings usually only once a day by each parent, most often at dusk. Adults spend the night roosting at or near the nest site. References External links Black swift Stamps from the Lesser Antilles: Dominica at bird-stamps.org American black swift Native birds of Western Canada Native birds of the Western United States Birds of Central America Birds of Hispaniola Birds of the Dominican Republic Birds of Haiti American black swift American black swift