We do not see them when driving over bridges in the Montreal area, but pairs of peregrine falcons nest on most of these urban infrastructures. Young falcons have also been born in the last few days on the Mercier Bridge, where adults of this species once on the verge of extinction return year after year.
Biologist and senior director of Environnement Faucon, Marilou G. Skelling argues that two of the four eggs of the breeding pair hatched between May 11 and 15. They are the first youngsters observed this year by her and her team, who monitor peregrine falcons on the bridges managed by the government corporation Ponts Jacques-Cartier et Champlain Incorporée.
The Mercier Bridge falcons are monitored by a camera, which made it possible to see one of the adults feeding one of the chicks. Environnement Faucon also carries out weekly on-site follow-ups, especially when the period of the first flight of the falcons approaches. This critical stage in the life cycle of these raptors is not always successful on the first try, points out Ms.me Skelling. “I once picked up a falcon from a building site. It can be put back near the nest, high up, to avoid the risk of predation or collision. »
Nesting at the Jacques-Cartier Bridge
In addition to the Mercier Bridge, a couple nests on the new Champlain Bridge and for two years now, peregrine falcons have been back on the Jacques-Cartier Bridge. For several years, recalls the biologist, there were no nesting birds of prey on this bridge. If there is no camera to confirm that they are currently incubating eggs, the observations of biologists suggest that the thing is possible this year.
Other bridges in the region have their couple of falcons, which would have been unthinkable a few years ago. In the past, the peregrine falcon has indeed been decimated, mainly due to the massive use of DDT, a highly toxic pesticide that has caused chronic reproductive problems in these birds. And even though DDT was banned in Canada in 1972, the situation remained critical for several years, in particular due to the persistence of the pesticide in the environment.
The first inventories carried out in Quebec, in the St. Lawrence valley, indicated for example that the species was, so to speak, wiped off the map, before it began to gain a few rare breeding pairs in the 1990s.
The numbers of these raptors ended up increasing and in a report produced at the request of the Government of Quebec and published in 2022, it is pointed out that “after having experienced a good increase in its numbers and a slowdown more recently, the peregrine falcon would be well on the way to recovery”.
Urban housing
Although its situation has greatly improved in Canada, the species still faces certain threats, including collisions with power lines, cars or building windows, disturbance by climbing or hikers, as well as wind turbines.
Part of the comeback of this falcon can be explained, however, by its ability to adapt in an urban environment. “The falcon has adapted well because there are a lot of prey in urban areas, such as pigeons, but also high structures which are in a way the equivalent of a cliff”, explains Marilou G. Skelling.
In the wild, falcons nest on cliffs. They do not build a nest, but choose a flat surface with gravel in which they can lay their eggs and hold them in place.
This is also why we find this type of small rock in the falcon nesting box installed at the top of the tower of the Roger-Gaudry pavilion at the University of Montreal. The female peregrine falcon, named “Eve”, laid her four eggs between April 16 and April 23, and the falcons are expected to be born somewhere around May 23. It can also be observed 24 hours a day in full brooding thanks to a camera whose images are webcast.