|A mix of birds gather around a snow-covered bird feeder during a winter day. According to UW researchers, birds typically found in more southerly regions are gradually pushing north. Photo: Martha Allen/Cornell Lab of Ornithology|
Over the past twenty years, the common birds at eastern North America’s backyard bird feeders in winter have changed subtly, most likely as a result of a warming climate. In this week's journal Global Change Biology, University of Wisconsin-Madison wildlife biologists Benjamin Zuckerberg and Karine Princé document that once rare wintering bird species are now commonplace.
Carolina wrens have greatly expanded their wintering range
Photo: Michele Black/Cornell Lab of Ornithology
Using more than two decades of data on 38 species of birds gathered by thousands of “citizen scientists” through the Cornell University Laboratory of Ornithology’s Project FeederWatch, the researchers show that birds typically found in more southerly regions are moving north gradually, restructuring the communities of birds that spend their winters in northern latitudes.
The researchers measured the changes over time in the abundance of 38 bird species at feeders in eastern North America, over a 22-year period on the flocks of birds that gather at backyard feeding stations.
Zuckerberg says. “Birds have always been very good indicators of environmental change.” Princé notes that other environmental changes, such as the pervasive human impact on landscape, may also be exerting an influence on the observed changes in the composition of birds attending winter feeding stations in eastern North America. “Climate change should not be viewed as the sole driver of changes in winter bird communities, but this signal is a pretty strong,” she explains.
Journal reference: Global Change Biology
Provided by University of Wisconsin-Madison
Cardinals move north: http://goo.gl/kiMcIW
Everyone can participate in the Great Backyard Bird Count http://goo.gl/WM83on
House Wren didn't migrate this winter http://goo.gl/2JlaCz
Most common winter birds in Michigan http://goo.gl/kPTb9v