The Chimney Swift is a species of insectivorous bird, which nests, roosts, and feeds mainly in urban areas, such as the City of Ann Arbor. They look like cigars with wings, and are charcoal gray, with stiff wingbeats, and a notable chittering call. They eat up to 1/3 of their body weight in insects each day, and thus benefit us greatly. When old growth hollow trees were lost to logging in previous centuries, these birds adapted to using urban chimneys as substitute places to nest and roost.
Now chimneys are essential to their lifecycle and survival. Chimney Swifts cannot perch on tree limbs like many other birds, since with their specialized foot shape they can only cling to a vertical surface.
The chimney at 415 W. Washington is a good example of a large Chimney Swift roost, hosting at least 1,400 swifts in August 2018.
These birds roost in great numbers, huddled together for warmth in chimneys at night, during spring and fall migration, and throughout the breeding season.
A single pair will use one chimney for nesting, but other non-breeding birds need chimneys for roosting too. The loss of large chimneys for roosting is one reason that this species is in steep decline, losing more than 70% of its population in the last 50 years. Capped or metal chimneys cannot be accessed by these birds, and older buildings with suitable chimneys are being torn down and replaced by newer construction, which may lack chimneys altogether.
The sight of Chimney Swifts spiraling into chimneys at dusk is enjoyed by many Ann Arbor
citizens. Watch hundreds of swifts enter the chimney at 415 W. Washington in the video below.
General Chimney Swift Information
Washtenaw Audubon Society - Chimney Swift Fact Sheet
Michigan Audubon Society - Chimney Swift Conservation
All About Birds - Chimney Swift
Wisconsin Chimney Swift Working Group
Ontario Swift Watch
415 W. Washington Building
Resolution to Direct the City Administrator to Evaluate Preservation of the Chimney Swift Roost at 415 West Washington Street
Queen's University Paleoecological Environmental Assessment and Research Laboratory -
Historical pesticide applications coincided with an altered diet of aerially-foraging insectivorous chimney swifts