A secretive group of volunteers watches Toronto's rooflines in a bid to preserve a bird's dwindling urban habitat.
“The show,” said Tim McCarthy, “is about to start.” The recently retired bond trader was standing across the street from an old brick church, eyes eagerly scanning the darkening sky from behind round-rimmed glasses. When the sun was just below the horizon, two tiny, silhouetted birds winged their way into view high overhead. Their movements were ungraceful, frenzied, violent. Rebecca Elbourne and Gail Fraser stood with McCarthy on the sidewalk, feigning nonchalance. “Now we need to be discreet,” Fraser warned. “People are standing there outside the church.” Elbourne turned her back on the birds and the growing group of parishioners. “You guys watch them,” she said. “I’ll look this way so it looks like we’re having a conversation.” The two birds were joined by a third, then a fourth. They began to fly in erratic circles above the mouth of the church’s small brick chimney. “It’s just like water going down a drain,” McCarthy said. Eventually, the four figures plunged headlong inside, one by one. What little light was left faded away. No more birds appeared.
As the volunteer coordinator for a fledgling conservation project called Toronto Swiftwatch, Elbourne keeps track of dozens of similar nest sites all over the city. Her records represent a summer’s worth of discoveries by a small handful of volunteers worried about the fortunes of an embattled, urban, cigar-shaped bird—the chimney swift.
According to the Ontario Ministry of Natural Resources, the chimney swift is a species at risk, and Elbourne and her colleagues are determined to preserve its preferred summer habitat: the chimneys of eastern North America. But despite having identified 83 nest sites in Toronto since the search began in mid-June, Swiftwatch has yet to reveal to any unsuspecting chimney owners that they are hosting a group of birds. “If I were the owner of a chimney,” McCarthy said, “and didn’t know a lot about birds, and maybe didn’t care a lot about birds, and someone came up and said, ‘Hey Mac, you’ve got some birds in your chimney, and we’re trying to save ’em,’ as soon as the door closed, I’d be onto the roofer to come and cover the chimney up.” Although talking to homeowners must eventually be part of what they do, for now, without any effective means to ensure the preservation of inhabited chimneys, Swiftwatch volunteers doing field work are as inconspicuous as the little birds themselves.
In a café near the church, before the evening’s excitement, Elbourne, McCarthy, and Fraser waited for the time when the birds would begin returning home for the night. They shared their best strategies for discreetly staking out a potential nest. “You know what I do?” asked Fraser, a York University professor in the environmental studies department who has been monitoring chimneys since 2009. “I sketch the building. I pretend I’m an artist.” She laughed. “I’ve got all these terrible drawings of churches.”
That it can’t go on like this forever is understood. “There will be a point at which an approach will need to be made,” said Elbourne, who got involved with Swiftwatch this summer, shortly after earning her master’s in biology. “But we want it to be done in the right way.”
They may find that they can’t afford to wait. Centuries ago, when the old-growth forests where they spent their summers began to be cut down by European settlers, these enterprising birds moved into the chimneys for which they are now named. At first, city life suited chimney swifts well, but, as heating technology has advanced, they have begun to lose their man-made habitat. The old, unlined brick structures of which the birds are so fond are increasingly being replaced with lined metal flues unsuitable for nesting. Bird Studies Canada, the non-profit conservation group that runs Swiftwatch, estimates that the chimney swift’s population has declined 96 per cent over the last 40 years.
Loss of habitat may not be the species’ only problem. A two-metre-tall pile of guano, deposited over 50 years and recently discovered in a Queen’s University chimney, has raised questions about how the bird’s diet has changed over time. Analysis of the droppings suggests that use of the now-banned pesticide DDT might have reduced the number of nutritious winged beetles on which the birds like to prey. Indeed, a study released by BSC earlier this year shows that all aerial insectivores—birds, including the chimney swift, that eat flying insects out of mid-air—are in sharp population decline. “We may not be able to do anything about the food shortages,” Elbourne said, “but we can do something about the potential habitat shortage.”
While the extent of what they can do in this regard is still unknown, BSC has been working with the City’s environmental planners to explore ways of preserving chimneys using municipal building-permit processes. As a threatened species, chimney swifts have their habitat protected by provincial legislation, but according to Kristyn Richardson, stewardship biologist for BSC, the Ministry of Natural Resources doesn’t always enforce the rules. “They’re understaffed and they’re overworked, and they don’t have time to do everything,” she said. “It’s unfortunate, but it’s the reality.” Often, she added, the province simply doesn’t know which chimneys are inhabited in the first place, which is why Swiftwatch has placed such an emphasis on identifying nests. “There’s so much habitat out there that we don’t know about yet,” Richardson said. “If we don’t know where the habitat is then we absolutely cannot protect it.”
For now, though, the volunteers’ surreptitious search for nests has been placed on hold, as the Toronto swifts have all set out for their winter homes in South America. Many sites still remain to be identified. Even then, the work will be only half done. “It’s going to be a tough one,” said McCarthy, who located some 15 inhabited chimneys this summer, more than any other volunteer. “At some point, we’re going to have to go knocking on doors and say, ‘Hey mister, you’ve got 300 swifts in your chimney. You can help us.’”