A billion birds have disappeared from North America since 1970, and a third of bird species across the continent are threatened with extinction, a new report says.
The first State of North America’s Birds report finds that of 1,154 bird species that live in and migrate among Canada, the U.S. and Mexico, 432 are of “high concern” due to low or declining populations, shrinking ranges and threats such as human-caused habitat loss, invasive predators and climate change.
Steven Price, president of Bird Studies Canada, a member of the North American Bird Initiative behind the report, says that since 1970, “the estimate is we’ve lost at least a billion birds from North America…. The trend lines are continuing down. They have to be turned around or will fall below a threshold where they can be recovered.”
Most threatened, with more than half the species of “high concern” are ocean birds such as northern gannets, tropical and sub-tropical birds, including many that breed in Canada and the U.S., but winter in Mexico.
There are also steep declines in coastal shorebirds like semipalmated and western sandpipers and red knots, which have lost 90 per cent of their population; grassland birds such as the greater sage grouse, Sprague’s pipit and chestnut-collared longspur; and aridland birds.
The North American Bird Conservation Initiative is a collaboration of conservation groups and scientists, in all three countries. The report was released partly to mark the 100th anniversary of the 1916 Migratory Bird Convention between Canada and the U.S. Information in the report is based on data collected by citizen scientists through bird surveys and counts since the 1970s and analyzed over the past 18 months.
It follows a similar report that focused on Canada in 2012 and found a 12 per cent drop in bird populations since 1970. But because many birds make very long migrations, Canada’s birds are “not really Canada’s — they’re shared across three nations,” said Price.