The skull of Oculudentavis, found encased in amber, provides new clues into the transition from dinosaurs to birds and may be smallest of either ever found.

Climate change has advanced the arrival of spring by as much as several weeks in some parts of the US. This can mean major crop losses and disconnects between species that need each other to thrive.

Millions of Americans feed wild birds, especially in winter and spring. Studies show that this can influence birds' health and behavior in surprising ways.

North America's prairies once were home to millions of wild animals. Today, most of that land is farmed or developed, but some grasslands have never been plowed and could be rewilded.