Environment News Service: Driven by a warming climate, North American birds are moving northward and inland, according to new analyses by scientists with the National Audubon Society of 40 years of observations by birdwatchers. Sophisticated computerized analysis of data gathered during Audubon’s Christmas Bird Counts since 1968 show that 58 percent of the 305 widespread species that winter on the continent have shifted north, some by hundreds of miles. “Experts predict that global warming will mean …