The Chimney Swift Fund: Swiftly restoring habitat brick-by-brick

By Gwendolyn Clark, Chimney Swift Chimney Restoration Fund Coordinator, and Andrew Coughlan, Associate Director, Québec and Atlantic

For many bird lovers, spring means dusting off the binoculars and heading out to see what species the warmer weather brings. Experiencing spring bird migration can often seem like a long shot for people living in busy cities. And yet, each year millions of birds pass over our homes on their way north, and millions more make cities their destination. These urban birds settle everywhere, from street light posts to house gutters. They’re all around us if you know where to look!

I experienced this first-hand on a cold spring evening last year in the heart of downtown Toronto. Around 60 of us had gathered at the Moss Park Armoury to watch a spectacle that very few have seen, although it happens all around us every spring. As dusk fell, the sky filled with twittering as hundreds of little birds began circling the armoury chimney. Against the pale sky, their classic cigar-shaped bodies and boomerang-shaped wings stood out. More and more birds appeared until finally, without warning, they started diving into the chimney in a steady stream. Less than a minute later, they were gone, and the air fell silent.

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Dozens of bird lovers gathered at the Moss Park Armoury chimney to watch the Chimney Swift spectacle. Photo: Olivia Carvalho

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Chimney Swifts have short, stubby bodies shaped like cigars. Their wings are long, pointy, and curved like a boomerang. Photo: Brandon Holden

The dramatic sight of hundreds of Chimney Swifts entering a chimney to rest for the night (roost) is one of spring migration’s best-kept secrets. You can see it in cities and towns across eastern Canada, from Manitoba to Nova Scotia. Yet, it has become rarer in recent years. One of the main reasons for this trend is the loss of chimneys the swifts need.

Chimney Swifts are unique because they can’t perch on branches or wires like other birds. Instead, they hang on rough vertical surfaces, using their long claws to hold on. This behaviour means they can only nest and roost in open chimneys with rough inner surfaces. When chimneys are blocked (for example, with a cap) or lined with metal, the swifts can no longer use these sites.

Screens and metal liners with spark arrestors are two chimney components that prevent Chimney Swifts from using a site. Any part that blocks the opening, such as a cap, is also problematic. Photo: Gwendolyn Clark

Chimney Swifts hang off of vertical surfaces using their long claws. For fledglings like these, having rough surfaces to cling to is essential as they build up their flying strength. Photo: Nelson Poirier

The disappearance of usable chimneys has had real consequences for Chimney Swifts in Canada. Numbers have dropped by almost 90% since 1970. Such a dramatic decrease is worrisome, but all is not lost! If we act now to stop the loss of more chimneys, there is every hope that these amazing birds can recover. Enter the Chimney Swift Chimney Restoration Fund (Chimney Swift Fund)!

Birds Canada and several partners created the Fund in 2022 with funding from Environment and Climate Change Canada. The Fund aims to protect Chimney Swift nesting and roosting structures by restoring them. Its approach is to offer grants covering up to 50% of the total project costs for such repairs.

To receive this financial support, the Fund requires owners to agree to keep their chimneys usable for swifts for at least 10 years. This way, it delivers a long-term solution to the habitat loss problem.

Because of this potential, the Fund’s relaunch in 2024 was a huge conservation win for Birds Canada, its partners, and Chimney Swifts.

The Chimney Swift Fund supports chimney restoration projects like this one in Boucherville, Québec. Photo: Ville de Boucherville

Over the past six months, we worked with dozens of property owners across eastern Canada, aiming to support as many projects as possible. By March of 2025, seven projects received a grant from the Fund, totalling over $164,000 of support. The sizes of the individual grants range from $2,213 to $68,197, highlighting the diversity of the repairs. These included everything from small maintenance jobs like repointing to complete rebuilds. The chimneys also vary in their geographic location, the habitat they provide for swifts, and the number of birds they support. By restoring a variety of chimneys, the Fund can ensure that Chimney Swifts have access to the habitat they need across Canada.

The seven restored chimneys cover a wide geographic range and provide both nesting and roosting space for swifts.

For example, the Fund helped finance repairs to two nest chimneys this year. The first was to a duplex chimney in Montréal, Québec, that has offered swifts a place to nest in the heart of one of Canada’s busiest metropolises since 2022.

The second was a chimney on a historic house in Wellington, Ontario, that acted as a nest site for several years until it was covered by a screen. Following the removal of the screen and masonry repairs, we are confident that this site will once again offer a nesting site for the species.

Chimney Swift pairs raise 4-5 young per year, so preserving nesting chimneys in this way can do wonders for helping the species recover!

This restored chimney in Montréal, Québec, has housed nesting Chimney Swifts since 2022. How do we know? They left the clearest sign possible – an old nest (top left)! Photo: Marilyne Clément

Some chimneys act as both nesting and roosting sites. As roosts, they support varying numbers of swifts, as illustrated by four chimneys restored this year. The church chimney in Martinville, Québec, is a smaller roost, recording up to seven swifts per night. The chimney on a repurposed historic house in Fredericton, New Brunswick, is larger, maxing out at 13 swifts. Similarly, the church chimney in Gatineau, Québec, hosts up to 18. Conversely, the chimneys of the town hall in Hampton, New Brunswick, have recorded up to 64 swifts per night! Because these sites house Chimney Swifts during two life cycle stages, they are even more important for the species. Their restoration should benefit both the species’ survival during migration and the number of chicks raised.

With their migration underway, the swifts will soon return to the restored chimneys. Nowhere is their arrival more anticipated than at the old Owen Sound courthouse in Ontario. This chimney is a large spring roost, averaging 125 swifts per night! Moreover, it is the only remaining roost of this size within a 25-km radius. In short, it is the most important Chimney Swift site around. Due to the state of disrepair of the chimney, it was feared that the structure might be lost from the landscape. Happily, the Fund was able to work with the property owner to restore the structure in the spring of 2025. With the work complete, the chimney is ready to welcome the hundreds of returning residents in a few weeks. In a world where development projects often threaten Chimney Swift sites, this victory is rare. It shows that a lot can be achieved if we work with property owners to steward these key sites.

The Owen Sound old courthouse chimney was falling apart by 2024 (left). With support from the Fund, the chimney was restored in time for the upcoming return of the swifts. Photo: Peter Middleton

As the swifts stream in from northwestern South America, how do we know they will take to their remodelled digs? Well, the Fund has a great track record on this count. All six chimneys restored in the Fund’s pilot year housed swifts in both years following the repairs. Nesting chimneys continued to house breeding swifts, and roosting sites offered shelter for individuals on migration. The Pohénégamook, Québec, and Colchester, Ontario, roosts even counted record highs (407 and 108 swifts)! This evidence tells us that the restorations successfully preserved the chimneys for the species. With such a strong precedent, we’re confident that the hundreds of swifts returning to the chimneys restored over the last few months will appreciate their updated housing.

What is the future of the Fund? The need for the Fund will only increase as old chimneys fall into disrepair and repair costs stay high. With the successes that the Fund has had so far, we at Birds Canada hope that it can continue in some form. The first step is knowing which chimneys need attention and which are used by swifts. This is where you come in! One of the only ways we can get this information is through volunteer surveys. If you want to help with these observations, please contact your regional SwiftWatch team. And if you’re craving a spring migration experience, stay tuned for upcoming Swift Night Out events, or grab a folding chair and head down to your local church, school, or heritage building. Then sit back and enjoy the free show!