The chimney swift (Chaetura pelagica) is a bird belonging to the swift family Apodidae. A member of the genus Chaetura, it is closely related to both Vaux's swift and Chapman's swift; in the past, the three were sometimes considered to be conspecific. It has no subspecies. The chimney swift is a medium-sized, sooty gray bird with very long, slender wings and very short legs. Like all swifts, it is incapable of perching on flat surfaces, and can only perch on vertical surfaces. Many fly around all day and only come down at night when roosting.

The chimney swift feeds primarily on flying insects, but also on airborne spiders. It generally mates for life. It builds a bracket nest of twigs and saliva stuck to a vertical surface, which is almost always a human-built structure, typically a chimney; historically (before European colonists built chimneys), they nested in hollow trees (including old pileated woodpecker nest holes), a few still do so, though only rarely. When disturbed by potential predators (including humans) at the colony, adult chimney swifts slap their wings together after arching back and taking flight, making a very loud noise known either as "booming" or "thunder noises". When disturbed, nestlings make a loud, raspy raah, raah, raah sound. Both sounds seem designed to startle potential predators.

The chimney swift carries a number of internal and external parasites. It is the type host for the nematode species Aproctella nuda,

After sudden temperature drops, the chimney swift sometimes hunts low over concrete roads (presumably following insect prey drawn to the warmer road), where collisions with vehicles become more likely. More than 700 were found dead. The following year, roost counts in the province of Quebec, Canada, showed a decrease of 62 percent, and the overall population in the province was halved. Sherman remarked that although the tower had been designed with a limited knowledge of the nesting behavior of chimney swifts, after many years of observation she believed that the original design was ideal.

Notes

Cited texts

  • Birds of the World - Chimney Swift
  • Chimney Swift Conservation Project—Driftwood Wildlife Association
  • Ralph W. Dexter research on chimney swift
  • Photos from Flickr's Field Guide Birds of the World
  • Sound recording at Florida Museum of Natural History