Chimney Swift
A protected bird that nests and roosts inside chimneys and vertical shafts each spring and summer.
How to identify
A small, dark gray bird about 5 inches long, with long, curved wings and a short tail, often described as a cigar with wings. It rarely perches, clinging to vertical surfaces instead.
Why it is a problem for commercial facilities
Swifts nest and roost in chimneys, air shafts, and vents, bringing noise, debris, and droppings into buildings during the breeding season.
Protected status
Federally protected under the Migratory Bird Treaty Act (MBTA). Birds, active nests, and eggs cannot be harmed or disturbed without a U.S. Fish and Wildlife Service permit. Deterrents and exclusion installed before nesting do not require a permit. Chimney swift populations have declined significantly, so work is timed around their migration.
How BSI controls it
- Chimney caps and screens installed after swifts leave for fall migration
- Cleanup and decontamination of nesting debris
- Exclusion netting for shafts and vertical openings
Where we see it most
Municipal and government, Commercial and industrial.
Common questions
When can a chimney be capped?
After the swifts migrate in the fall and the chimney is confirmed empty. Capping while birds are present is illegal.
Are chimney swifts protected?
Yes. They are covered by the MBTA, and their nests cannot be disturbed while active.
Dealing with this species at your facility?
Send two photos and the project location. We will come back with a recommended system and scope.