About the Chimney Swift
A small, dark “cigar with wings,” this is the common swift of the eastern half of North America. Its original nest sites (hollow trees, cliffs) have largely been substituted with human-built structures such as chimneys or building shafts, so it is especially common in urban areas. Monotypic. Length 5.3".
Small, dark; squared, spine-tipped tail; narrow-based wings often appear markedly pinched at the base during secondary molt in late summer, early fall. Adult: brownish black overall; paler chin, throat; slightly paler rump. Plumage can appear browner with wear or appear blacker from contact with chimney soot. Juvenile: nearly identical to adult, but with whitish tips to the outer webs of the secondaries, tertials. Flight: usually rapid, fairly shallow wingbeats, including quick turns, steep climbs, short glides. V-display of pairs involves long glides with wings raised in a V-pattern and some rocking from side to side.
The Vaux’s is very similar but is slightly smaller, paler; differs subtly in shape; has higher-pitched calls.
Call: commonly heard; quick, hard chippering notes, sometimes run together into rapid twitter.
Status and Distribution
Common. Breeding: widespread in variety of habitats; most abundant around towns, cities. Possibly breeds north to Newfoundland. Small numbers summer regularly in southern California (though fewer since 1990s), with breeding documented; possibly also bred in Arizona. Migration: migrates in flocks during the day, mainly along the Atlantic coastal plain, Appalachian foothills, and Mississippi River Valley. Large concentrations may appear during inclement weather; hundreds may roost in chimneys. First spring arrivals are in mid-March in southern states; peak arrivals in northernmost breeding areas are late April–mid-May. Most have departed breeding areas by late September–mid-October; latest fall migrants occur in early November. Winter: most or all winter in Upper Amazon Basin of South America; unrecorded in North America in mid-winter, but records as late as December. Vagrant: casual away from California in West, mainly May–September; accidental on Pribilof Island, Alaska, and in western Europe.
Numbers probably increased greatly with the availability of urban nesting sites and with forest clearing, but population declines have been noted since the 1980s.
—From the National Geographic book Complete Birds of North America, 2006