The Chimney Swift (Chaetura pelagica) is one of the nine swift species in the New World genus Chaetura. Several Chaetura species, including C. pelagica, originally built their nests in hollow trees but now often nest inside chimneys or other human-built structures. The Chimney Swift is the only swift regularly occurring in eastern North America. In late summer, large flocks may be seen in the sky at dusk, giving their distinctive chattering calls. Chimney Swifts feeding on flying insects are a familiar sight in the open skies over towns and cities across the eastern United States and adjacent Canada,. Within the Chinmey Swift's range, artificial nest sites such as chimneys are far more common than suitable hollow trees.
Chimney swift courtship involves aerial displays. Nesting is often colonial and the breeding pair is often assisted by an extra adult “helper”. The nest, which is constructed by both sexes, is shaped like half a saucer and is made of twigs glued together with the birds’ saliva. Adults break off short dead twigs from trees while zooming past in flight. Clutch size is 4 to 5 white eggs (range 3 to 6). Incubation (for 19 to 21 days) is by both parents. Both parents feed young (by regurgitating insects). Young may climb out of the nest after around 20 days, clambering up vertical walls. Young typically first fly at around 28 to 30 days.
Chimney Swifts migrate in flocks, apparently during the day. They winter in eastern Peru, northern Chile, and in the upper Amazon basin of eastern Peru and northwestern Brazil.
(Kaufman 1996; AOU 1998)