When chimney swifts aren’t breeding, they often roost together in big chimneys. Big clouds of the birds can sometimes be seen diving together into one at the end of the day – a 'swiftnado.'Roger Hangarter/Supplied
On a warm evening earlier this summer, a dozen or so people sat on the grass at the University of Toronto’s downtown campus, staring at an old chimney. They stared as the evening sun made the yellow bricks of the chimney glow. They kept staring as the light began to fade. They swivelled their heads to scan the sky above, then stared at the chimney some more.
Far overhead, small dark shapes dodged and soared – chimney swifts, tiny, fascinating urban creatures whose time among us could be coming to an end.
The people on the lawn were waiting for the moment when the swifts would dive into the chimney to roost. This used to be a common sight in Toronto. In its early days, when people heated their houses with wood, coal or oil, it was a city of chimneys. Swifts occupied them in the thousands.
Before European settlement, they had roosted in hollow trees. When settlers cut down much of Southern Ontario’s forests, they took up residence in towns and cities. If you can’t beat ‘em, join ‘em.
But cities change. The march of progress meant that city dwellers gave up on coal and started heating with electricity and natural gas. Many householders capped their chimneys or lined them with metal. The swifts couldn’t get in.
The birds head to South America for the winter, returning in the spring to raise a family – a roundtrip of 10,000 kilometres.George Peck/Supplied
As office buildings and condominium towers replaced warehouses and factories in downtown Toronto, thousands of chimneys simply disappeared. The swift population has declined by 90 per cent since 1970. The family to which they belong, the aerial insectivores, which also includes swallows, flycatchers and nightjars, has experienced the greatest decline of any group of birds in Canada.
The naturalists from Birds Canada who organized the evening swift watch are hoping to save them. They are working with institutions like the U of T to preserve existing chimneys. They are striving to persuade homeowners to uncap their chimneys. They are working with building managers and chimney sweeps (yes, they still exist) to identify roosting sites.
Perhaps most important, they are trying to persuade the public that swifts are worth saving in the first place.
Tuning into the melodic mystery of bird song
Most people are barely aware of the birds. They fly high in the air, much higher than more familiar insectivores such as barn or tree swallows. Their high-pitched twittering, though lovely in its way, is not as dramatic as the cheer-cheer of the cardinal or the cry of the blue jay. You need to be alert to see them plunge into a chimney.
But those who take a minute to learn about them might be surprised. Swifts don’t perch on branches or overhead wires like many birds. Superb flyers, they instead spend just about every waking minute aloft, scooping up insects with their gaping mouths. They eat, mate and defecate on the wing. Rather than grab twigs from the ground to build their nests, they swoop past trees and snatch the ends of branches. They even bathe in flight. As the Cornell Lab of Ornithology puts it, “they glide down to the water, smack the surface with their bodies, and then bounce up and shake the water from their plumage as they fly away.”
They eat something like 1,000 insects a day. Mosquitoes are a favourite. They head to South America for the winter, returning in the spring to raise a family – a roundtrip of 10,000 kilometres. Mother and father build their nest together, gluing it to the inside of the chimney with their sticky saliva. They take turns incubating the eggs. Unmated birds sometimes take shifts sitting on the nest, too. It takes a village.
When swifts aren’t breeding, they often roost together in big chimneys. Great clouds of swifts can sometimes be seen diving together into one at the end of the day – a “swiftnado.” You can see the phenomenon at the Moss Park Armoury on the east side of downtown Toronto, where 2,000 of the birds have been observed swirling down into the chimney at one time.
The campaign to save the swift is enjoying some modest success. Provincial legislation requires builders to replace destroyed swift habitat. That explains why an old chimney stands alone on a lot near Christie Pits in west-end Toronto. A firm of architects built it to replace the chimneys of a demolished Catholic school.
In Hamilton, the provincial transit agency, Metrolinx, left a single chimney standing when it demolished some buildings for the construction of a new light-rail line. Metrolinx said it “made visual observation of a chimney swift entering.” That is to say, it saw a bird.
At the U of T that summer evening, swifts made several passes at the chimney as sunset drew nearer and the group on the lawn watched. Said to resemble “a cigar with wings,” swifts can manoeuvre with staggering agility. Finally, to a chorus of “oohs” and “ahs,” a single swift dove into the chimney – safe, at least for now.
Mother and father chimney swifts build their nest together, gluing it to the inside of the chimney with their sticky saliva, and take turns incubating the eggs.Ally Manthorne/Supplied