Populations of 20 common birds declining

By SETH BORENSTEIN, AP Science Writer
Fri Jun 15, 2:31 AM ET

The populations of 20 common American birds — from the fence-sitting meadowlark to the whippoorwill with its haunting call — are half what they were 40 years ago, according to an analysis released Thursday.

Suburban sprawl, climate change and other invasive species are largely to blame, said the study's author Greg Butcher of the National Audubon Society.

"Most of these we don't expect will go extinct," he said. "We think they reflect other things that are happening in the environment that we should be worried about."