Taking inspiration from bird feathers ... inspired flaps to a 3D-printed model airplane wing and mounted it in the wind tunnel, a 30-foot-tall metal contraption that simulates and measures ...

But a bird wing is vastly more sophisticated than anything composed of sheet metal and rivets. From a central feather shaft extends a series of slender barbs, each sprouting smaller barbules ...

Researchers may have just found the answer: Unlike birds, the evolution of bats' wings and legs is tightly coupled, which may have prevented them from filling as many ecological niches as birds.