Douglas H. Chadwick is an American wildlife biologist, author, photographer and frequent National Geographic contributor. He is the author of 14 books including The Wolverine Way and more than 200 articles on wildlife and wild places. In this episode of Nature Revisited, Douglas talks about his experiences with wolverines and the Glacier Wolverine Project, a 5-year study to uncover key missing information about the wolverine's habitat, social structure and mating habits. From dealing with blizzards, grizzlies, sheer mountain walls, and other daily challenges to survival, he and a team of volunteers tracked this elusive species to better understand it and the forces that threaten its future.