Monday, 2 July 2012

Bird numbers in decline across Canada, study finds

Canadian birds are becoming more rare than ever and it’ll be a hard struggle for us to keep them from vanishing altogether, according to a new study.

A coalition of environmental groups called the North American Bird Conservation Initiative released the State of Canada’s Birds report Wednesday. The report is the first comprehensive look at population trends of all Canadian birds in the last 40 years, and was authored by groups including Environment Canada, Ducks Unlimited and Bird Studies Canada.

Breeding bird populations had fallen about 12 per cent in Canada since 1970, the study found.

Of the 451 bird species native to Canada, about 44 per cent had declined in numbers since 1970. Horned grebe and northern pintail populations in central and southern Alberta had fallen by about 70 per cent.

These trends have been pretty much constant for 40 years and it’s hard to see how they can be reversed, said local birder Alan Hingston, who indirectly contributed research to the report through local bird surveys.

“I don’t see something that’s going to be easily reversed by individual effort.”

Falling feathers

While previous studies have suggested problems in some species before, this one was the first to look at all birds together, said David Howerter, national manager for Ducks Unlimited’s Institute for Wetland and Waterfowl Research and a member of this study’s steering committee.

“Some groups of birds are not doing very well,” he said.

There are about half as many shorebirds now as there were 40 years ago, for example, and about 85 per cent fewer swallows, swifts and nightjars.

Others are doing almost too well, he continued. Waterfowl are up by about 50 per cent, for example, while snow geese are now so prolific that people fear they’re damaging their arctic nesting grounds.

Raptors, particularly iconic birds like the bald eagle, have also made a comeback, said Dick Cannings, who co-ordinates Canada’s Christmas bird counts through Bird Studies Canada, largely as a result of a ban on DDT.

“You can go into downtown Edmonton now and there are peregrine falcons nesting in buildings, which would have been unthinkable in the 1970s.”

Some of these changes are easily explained. Birds like the endangered greater sage grouse are losing their habitat to oil and gas development, for example.

Ducks and geese, on the other hand, are now thriving due to decades of wetland conservation by groups like Ducks Unlimited, Hingston noted.

“Waterfowl are closely linked to the hydrologic cycle,” he noted, and recent wet years have also helped bring ducks back.

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