See the stunning winning images of the 2015 Photo Contest.
The Big Sleep
Scientists studying hibernation in mammals are finding promise for human medical applications.
Purging Trout to Save Frogs
A controversial fish-removal effort pits some angers against conservationists trying to save the mountain yellow-legged frog.
An Otterly Amazing Comeback
The North American river otter has returned to many U.S. states, only to once again be fighting old adversaries.
A Cardinal Bull's-Eye
A photographer captures a split-second, snow-splattered encounter.
What is This?
Test your wildlife knowledge. Can you guess what animal this is?