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By Rielle Hoeg, Aerial Insectivore Technician, Birds Canada

With spring on the way, keep an eye and an ear out for Chimney Swifts returning from South America! You may hear these birds twittering before you see them – they spend their days foraging for insects high up in the sky. Spanning just 30 cm from wingtip to wingtip, each of these grey-brown birds can eat upward of one thousand flying insects per day!  

Home to roost

Chimney Swifts return to central and eastern Canada in May and gather at communal roosts at night or on cold, wet days for resting. At dusk, anywhere from a few, up to several thousand, swifts perform an impressive acrobatic display as they “swiftly” tumble and dive into the mouth of a chimney, their preferred roosting location. 

Non-breeding swifts will continue to use these roost chimneys throughout the summer while nesting swifts will depart to nest in a chimney or other structure as a single pair. There, they build a 10-cm wide nest by attaching twigs to a rough surface with their glue-like saliva. On relatively warm, clear, windless days, parents leave the nest to hunt for insects to feed their young. On cold, rainy days, swifts will remain inside the roost or nest chimney and huddle for warmth. 

Between August and September, swifts gather at roosts again before making their journey south for the winter.

Chimney Swift Photo: Andrés Jiménez

A swift decline

Unfortunately, along with other species that rely on flying insects, Chimney Swift populations are in trouble. Since 1970, Canadian populations have declined by about 90%, and they are listed as “Threatened” under the Species at Risk Act. Chimney Swifts face multiple threats including declines of flying insect prey, increased storms due to climate change, and habitat loss. 

Adult Chimney Swift with its young Photo: George Peck

Historically, Chimney Swifts nested and roosted inside large, hollow, dead trees in mature forests as well as caves. With European colonization came logging and agriculture practices that removed many trees from the landscape, but this brought a new habitat: chimneys. 

Once again, swifts are facing breeding habitat loss, but this time, it is because chimneys are either destroyed, capped, or repaired using smooth metal liners, and there is no available alternate habitat. 

Funding to restore chimneys for swifts

Due to the ongoing loss of nest and roost sites, it is critically important to conserve as many of the existing structures used by swifts as possible. Birds Canada and partners have launched the Chimney Swift Chimney Restoration Fund to provide financial support to property owners who need to repair their chimneys. This program will help fund the restoration of chimneys or other structures that support, or have supported, Chimney Swifts to ensure these sites are not lost. The deadline to apply is April 21, 2022. To learn more about the Fund, including eligibility and how to apply, please visit this webpage.

Volunteer to count swifts

Locating and monitoring nest and roost sites is important, so we protect them for future generations of swifts. You can help by sharing all nest and roost sightings with Birds Canada through SwiftWatch in Ontario or the Maritimes, or with regional monitoring partners (e.g., Manitoba Chimney Swift Initiative; Nature London in London, ON; and Canadian Wildlife Service in Québec). Each year, between the end of May and early June, Citizen Scientists across Canada count swifts entering chimneys for the National Roost Monitoring Count to help monitor population levels. For 2022, observers are asked to count on May 21, May 25, May 29, June 2, and June 6. Additional counts throughout the breeding season and during migration are also welcome. More information can be found on the SwiftWatch website. We also welcome swift observations through eBird Canada or our Report a Sighting page

Chimney Swifts entering a chimney Photo: Peter Middleton

Hosting Chimney Swifts

If you have Chimney Swifts on your property, please let us know and we can help you be a steward and successfully host Chimney Swifts. Please consider avoiding using your fireplace or cleaning or repairing your chimney from May-September, keeping your fireplace damper closed when not in use, and retaining chimneys used by swifts if you intend to convert to a different heat source. Remember, because Chimney Swifts are a protected species, it is against the law to disturb, kill, or collect adults, nestlings, nests, or eggs. Chimney Swifts are long gone when we choose to use our fireplaces for warmth in late fall and winter, so are very good tenants. To contact Birds Canada and let us know about your swifts, please email if you are in the Maritimes, or if you are in Ontario.

Thank you!

Volunteers, stewards, and supporters are making a difference for Chimney Swifts! If you have participated in SwiftWatch, hosted swifts, advocated for them, or made a gift for bird conservation through Birds Canada, we thank you!

SwiftWatch volunteers Photo: Megan Hiebert
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