Some Manitobans, especially in older neighbourhoods, may have house guests that they don’t even know about or have heard, but never seen. Chimney swifts are small birds with cigar shaped bodies that migrate to Manitoba for the breeding season in summer. Swift populations have been in serious decline since the 1960s, some estimate a loss of about 95% of the population, due to the loss of habitat. They used to nest in hollowed-out tree trunks before losing much of their wetland habitat. Now, swifts have adapted to urban environments and often nest in chimneys in residential areas.
They use twigs and saliva, which is very sticky, to build bracket nests that stick to the inside walls of the tree or chimney, by sticking small sticks together and fastening them to the rough surface of the tree or chimney. Now, the chimneys that swifts used as a substitute for their natural environment are also disappearing, because fewer houses have chimneys or the chimneys may be in disrepair. Also, contractors or industry experts often advise homeowners to cap or line old chimneys to prevent any animals from getting inside.
In order to successfully reproduce, swifts need accessible chimneys to build nests and reproduce. Even active chimneys that are accessible can become too dirty and the build-up of soot prevents the swift nests from attaching to the walls. Swifts arrive in Manitoba in May and stay through the end of August, so the nest and birds do not interfere with using the fireplace. Also, swifts are not destructive birds that will get into homes or damage the chimney or structure of the building, so providing a home for them is not a concern. If you are concerned about the birds getting into the home, it is possible to screen the fireplace entrance through the summer.
If you do have a chimney that could be a home to chimney swifts, keep it clean so that the swifts can nest, as a single chimney could house as many as 50 swifts. Obviously, the fireplace should not be used until the birds have left for the season. Even if you have no use for the chimney, consider repairing it rather than removing it. Chimney swifts consume over 1000 mosquitoes and insects a day, so they are definitely good neighbours, especially in Manitoba. If you do have chimney swifts, the Manitoba Chimney Swift Initiative will designate you a Swift Champion and you can become a partner in supporting and monitoring their nesting and breeding. Contact MCSI for more information: https://www.mbchimneyswift.com/.
*Article originally printed in Prairie Wildlife Rehabilitation Centre newsletter.
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