Global Warming Pushing Bird Migrations Northward
Published 2/10/2009 10:55:13 AM by staff from ecoistabode
As global warming has pushed temperatures across the US upwards, birds across the country are wintering farther and farther northward each year. An Audubon Society study has found that bird species in North America are spending the winters about 35 miles farther north than they did 40 years ago.
The purple finch was the biggest northward mover. Its wintering grounds are now farther north along the latitude of Milwaukee, Wisconsin instead of Springfield, Missouri. Bird ranges can expand and shift for many reasons, among them urban sprawl, deforestation and the supplemental diet provided by backyard feeders, but researchers say the only explanation for why so many birds over such a broad area are wintering in more northern locales is global warming.
The study provides compelling evidence for what many birders across the country have long recognized that many birds are responding to climate change by shifting farther north. Previous studies of breeding birds in Great Britain and the US have detected similar trends, but the Audubon study covers a broader area and includes many more species.
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