by Diana Grier Ayton
David Bird helped some friends move recently. Not so remarkable at this time of year in Montreal, you might think, but in fact it was a first.
Bird's "friends" are a family of peregrine falcons and they were lured to their new home using a technique no one had ever tried before.
The peregrines had taken up residence on the top of the downtown Royal Bank headquarters and were incubating their newly-laid eggs. The location was a precarious one, however, because the nesting space was small and once the chicks hatched, they could easily fall to their deaths. Also, the vigilant expectant parents were making life very painful for the building's window washers.
The usual solution in such a situation is to remove the eggs from the nest, incubate them mechanically and rear the chicks by hand. Eventually, they would be released back into the wild. That solution is not an ideal one, since raising the chicks is labour-intensive and the female peregrine, on the loss of her eggs, would likely lay another batch--a phenomenon known as double-clutching.
|Professor David Bird (right) prepares to band peregrine chicks, assisted by Michel Beaulieu, Director of Services for the Stock Exchange Tower. Falcons banded in Quebec have been spotted as far away as Winnipeg and Detroit. Photo by Owen Egan|
"I knew the falcons had another nesting site at the Stock Exchange Tower in Place Victoria, one they'd used before," says Bird, who is director of the Avian Science and Conservation Centre at Macdonald Campus. He knew, too, that falcons frequently visit favourite "perches" on buildings throughout the downtown area.
"That gave me the idea to try something unusual. I planted some strange eggs in the other nest. Knowing that the female peregrine was in a hormonal mode to incubate, I thought the eggs might attract her to the old nesting site. If she established herself there, we could then switch the strange eggs for hers."
The falcons cooperated, the four peregrine eggs--which had been collected and incubated at Macdonald--were placed in the nest at the Stock Exchange Tower and the chicks hatched right on schedule.
The falcon family is particularly welcome at their 32nd-storey home. When they first nested there, members of the law firm Martineau Walker, who are also tenants of the building, created an elaborate information centre in the lobby. Making the display even more compelling these days are the pictures that are once again being transmitted from the rooftop nest site to a high-resolution TV monitor in the lobby.
Bird is very pleased with the results of his experiment, a procedure he's dubbed "clutch shifting" and is busy writing it up for a journal. "This success gives great hope to conservationists in other cities," he says.
Although only two of the chicks have survived, Bird says that's perfectly normal. "Newly hatched peregrines face all sorts of dangers, from getting caught in a wind shear and being crushed against a building to straying too far from home base on an early flight and being unable to get back. I'm very happy with the way this has gone and the people at Place Victoria are happy to have the falcons back. And the window washers are happy!"
To find out more about the peregrine falcon, check out Martineau Walker's on-line information centre at http://www.deev.com/Martineau-Walker/.