Bird Movements Reveal Global Warming Impacts

North American birds are moving northward and inland in response to global warming, according to a new in-depth report by the National Audubon Society.

Analyses of citizen-gathered data from 40 years of Audubon's Christmas Bird Count (CBC) reveal that 58 percent North American winter species shifted significantly north since 1966, some by hundreds of miles.

Movement was detected among species of every type, including more than 70 percent of highly adaptable forest and feeder birds. Only 38 percent of grassland species mirrored this trend, demonstrating the constraints of their severely-depleted habitat and suggesting that they now face a double threat from the combined stresses of habitat loss and climate adaptation.

"Experts predict that global warming will mean dire consequences, even extinction, for many bird species, and this analysis suggests that the process leading down that path is already well underway," warned Audubon President John Flicker. "We're witnessing an uncontrolled experiment on the birds and the world we share with them."

Published: February 25, 2009