It may still feel like winter, but nature is dropping hints.

In a sure sign of the changing seasons, migratory birds are slowly making their way back north right now. From tiny songbirds to enormous soaring cranes and eagles, spring’s earliest arrivers are ...

A new study of North American songbirds finds that birds can't keep up with the earlier arrival of spring caused by climate change. As a result, they're raising fewer young. By the end of the 21st ...