Guide to North American Birds
Conservation status Probably increased greatly in numbers after adapting to nesting in chimneys, much more readily available than hollow trees. In recent decades it has declined in some areas, but still widespread and common.
Family Swifts
Habitat Open sky, especially over cities and towns. Forages in the sky over any kind of terrain, wherever there are flying insects. Now most common over towns and cities; within its range, few forests remain with hollow trees large enough to serve as nest sites.
The only swift occurring regularly in the east. It once nested in hollow trees, but today it nearly always nests in chimneys or other structures. Because the bird can be easily captured and banded in such situations, it has been studied much more thoroughly than other North American swifts. In late summer, hundreds or even thousands of individuals may roost in one large chimney, gathering in spectacular flocks overhead near dusk.

Photo Gallery

Feeding Behavior

Forages only while flying, pursuing insects and scooping them out of the air. Often flies high but will forage very low during wet weather. Typically seen foraging in small flocks.


Eggs

4-5, sometimes 3-6. White. Incubation is by both parents, 19-21 days. Young: Both parents feed young, by regurgitating insects. Young may climb out of nest after about 20 days, creeping up vertical walls. Age of young at first flight about 28-30 days.


Young

Both parents feed young, by regurgitating insects. Young may climb out of nest after about 20 days, creeping up vertical walls. Age of young at first flight about 28-30 days.

Diet

Flying insects. Feeds on a wide variety of insects, including beetles, flies, true bugs, and moths; also spiders. Will concentrate at times on swarming insects, such as emergences of winged adult ants.


Nesting

Courtship involves aerial displays; in one display, two birds fly close together, one following the other, both gliding with wings held up in V. Breeding pair is often assisted by an extra adult "helper." Nest site is inside a chimney or similar hollow tower, usually well down from opening, in a well-shaded area. Originally nested (and sometimes still does) inside large hollow trees. Nest (built by both sexes) is shaped like half a saucer, made of twigs glued together with the birds' saliva. Adults break off short dead twigs while zooming past in flight.

Illustration © David Allen Sibley.
Learn more about these drawings.

Text © Kenn Kaufman, adapted from
Lives of North American Birds

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Migration

Migrates in flocks, apparently by day. A long-distance migrant, wintering in eastern Peru and perhaps elsewhere in the Amazon Basin of South America.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon

See a fully interactive migration map for this species on the Bird Migration Explorer.

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Songs and Calls

Loud, chattering twitters.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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How Climate Change Will Reshape the Range of the Chimney Swift

Audubon’s scientists have used 140 million bird observations and sophisticated climate models to project how climate change will affect this bird’s range in the future.

Zoom in to see how this species’s current range will shift, expand, and contract under increased global temperatures.

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Climate threats facing the Chimney Swift

Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.