The Hard Life of Birds

"To survive the cold, birds need to eat enough during the day to have the energy needed to shiver throughout the night."

That is a hard-life fact offered in today's Associated Press story about the Audubon Society study, released today, that "found that more than half of 305 bird species in North America...are spending the winter about 35 miles farther north than they did 40 years ago."

Global warming is cited as the probable cause.

""This is as close as science at this scale gets to proof," said Greg Butcher, the lead scientist on the study and the director of bird conservation at the Audubon Society. "It is not what each of these individual birds did. It is the wide diversity of birds that suggests it has something to do with temperature, rather than ecology.""