If it’s a yellow-crowned night heron you seek, the helpful members of the Ontario’s online birding community will direct you to precise GPS co-ordinates in Toronto. A Bullock’s Oriole? Go to Grenadier Pond in High Park, according to a bustling Discord server for the province’s birders. A dark-backed scaup? Try the red bridge in Tommy Thompson Park.
But the reception will be less hospitable to those hoping to find Toronto’s latest ornithological sensations: a pair of nesting American bald eagles that have taken up residence somewhere within the metropolis.
While bald eagles are numerous elsewhere in the country, they are relatively scarce in the skies over Toronto. A nest is even more unusual. The couple is the first documented breeding pair in the city’s history, according to both the Royal Ontario Museum and the Toronto and Region Conservation Authority.
The species is notoriously skittish around humans, an unfortunate trait for taking up residence in Canada’s largest city. While their arrival is being celebrated as a positive sign for an ecosystem slowly recovering from the ravages of DDT and other threats, local birders worry that the publicity could draw crowds, leading the eagles to abandon their eggs for more remote regions.
That’s why any mention of their location on the Discord server is being deleted. And in person, bird experts are guarded about how much they reveal.
“The birding community is excited,” said Mark Peck, an ornithologist with the Royal Ontario Museum. “But we have to be careful not to love this thing to death.”
There was little love for the bald eagle around time Toronto was established. In the early 1800s, as Toronto’s population was closing in on 10,000, settlers throughout North America regarded eagles as a menace to livestock and called for their eradication. Authorities offered bounties and authorized grisly hunting methods, such as pole-trapping, where people would place leg-hold traps atop poles to snare the predators. In 1842, John G. Howard, Toronto’s first official surveyor and engineer, bragged of shooting a bald eagle that “measured seven feet between the wings.”
By the 1900s, governments started to see the error of their ways and passed laws to protect migratory birds. The appearance of DDT and other chemicals in the 1940s undid any legislative advances. The insecticide, used in mass quantities throughout North America to control mosquitoes and pests, leached into waterways, contaminating the fish eagles eat. The chemical weakened egg shells. By 1963, scientists were warning of possible extinction. A complete Canadian ban on DDT in 1985, along with extensive conservation efforts across the continent, has largely brought the species back from the brink.
In 2009, conservationists celebrated when a pair began nesting in Hamilton’s Cootes Paradise Marsh. The couple has been returning ever since, but they tend to take flight if people get within 300 metres, said David Galbraith, director of science at the Royal Botanical Gardens, which oversees the marsh.
“We’re delighted that they’re here,” he said. “I think it’s a testament to the decades of habitat rehabilitation that we’re all putting in.”
In early February, some keen observers reported to the Toronto and Region Conservation Authority (TRCA) that they they’d seen clear courtship behaviour between two urban eagles. They would fly high over the city, lock talons and cartwheel together toward the skyline, releasing close to the ground. Perched in tree limbs, they would pass sticks back and forth.
They moved in together, taking over a nest abandoned by another species and expanding it to fit their massive girth, said Karen McDonald, senior manager, restoration & infrastructure, with the TRCA, careful to describe the mating rituals without giving away any location details. The agency avoided publicizing the nest, hoping a lack of exposure could improve the chances of survival for the couple’s eggs, which generally take about 35 days to incubate, but news reports earlier this week forced it to respond.
Ms. McDonald said that the return of a keystone species such as the bald eagle suggests other species up and down the food chain must be doing well. But it’s a precarious balance.
Eagles are monogamous and will often return to the same nesting site for years – as long as they can successfully raise their eaglets. A few years ago, bald eagles abandoned a nest in the Durham region, east of Toronto, likely owing to the presence of photographers and drones, said Amanda Guercio, a local naturalist. “So while the excitement and optimism surrounding the historic nest is fully warranted, it would be a shame for it to meet the same fate.”
With a report from Stephanie Chambers
Patrick White