3 Billion Fewer Birds In North America Since 1970

September 20, 2019

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A new study at Cornell University finds the number of birds in North America has dwindled significantly in the last 50 years. Nearly 30% of birds, including common birds like sparrows, have disappeared. This isn't an extinction, it's the total number of birds in the skies over the United States, Mexico and Canada. However, the findings raise concern that some familiar species could end up like the passenger pigeon, a species once so abundant that its extinction in the early 1900's seemed unthinkable.

In the online magazine Science, Ken Rosenberg, a conservation scientist at the Cornell University Laboratory of Ornithology and author of the study, said, "It's staggering." 

Ecologist Paul Ehrlich at Stanford University, who has been warning about shrinking plant and animal populations for decades, hopes this will be a wake-up call of sorts, "It might stir needed action in light of the public interest in our feathered friends."

As for what's causing the decline? In some cases, that may be subtle. Last week, toxicologists described how low doses of neonicotinoids, a common pesticide, made migrating sparrows lose weight and delay their migration. That hurts their chances of reproducing and surviving. Climate change, habitat loss, shifts in food webs, and even cats may all be adding to the problem.