Throughout the 1900s, North America’s littlest falcon was also described as the continent’s most common and widespread. Small but fierce and marked with bright plumage rare in the raptor world, the American kestrel (Falco sparverius) could be seen throughout the continent, diving and swooping in fallow fields or under the stadium lights at baseball games, hunting for plump moths or small mice. In the Montreal area, they lived in the suburbs, in places like Vaudreuil-Dorion and Île-Perrot, drawn by unused fields and abundant food.
And yet their numbers have plummeted in Montreal and throughout the northeastern region of the continent, mirroring the worrying free fall of multiple avian species. It’s estimated the kestrels’ numbers dropped 50 per cent between 1966 and 2015, according to the North American Breeding Bird Survey.
Bird populations in North America have been plummeting for the last half-century, experiencing a net loss of nearly three billion birds, or 29 per cent of their total, since 1970, according to a study published in Science magazine in October.
Unlike other raptors, the kestrel’s downturn is reminiscent of the loggerhead shrike (Lanius ludovicianus), a chunky songbird smaller than a robin whose numbers have fallen by 76 per cent since 1966. Once common here, they are now extinct in Quebec and considered endangered in the rest of Canada. Their fates could be linked to their comparable diet — both birds feed largely on insects, grasshoppers and beetles, and small mammals. And insect populations are declining, becoming victims to climate change, pesticides and habitat loss. One German study recorded a 75-per-cent drop in the numbers of flying insects over close to 30 years.
The 2019 State of Canada’s Birds survey found that aerial insectivores like swifts (Apus apus) and barn swallows (Hirundo rustica), who capture insects while in flight, have seen their numbers drop by as much as 60 per cent since the 1970s.
Source: Montreal Gazette, Jan 6, 2020