In the North American West, the primary corridor carnivores have been using for dispersal since the end of the last ice age extends from Alaska to Mexico. Twelve thousand years ago, two ice sheets covered much of this continent. As they melted, a path opened between them, enabling passage of creatures such as grizzly bears. Today, animals continue to use this ancient corridor. Indeed, I like to think of it as a "carnivore way," because of the carnivores who have worn deep trails in this pathway over millennia.
Obstacles to this basic need to roam, such as human development, can provide formidable threats to long-term survival of many species. For the large carnivores, it's not just about losing the freedom to move, it's about losing a natural process. They and other species use dispersal as a key survival mechanism, to maintain genetic diversity and adapt to climate change.
To learn more about the challenges grizzly bears, wolves, wolverines, lynx, jaguars, and cougars face, in 2013 I traveled the Carnivore Way. I talked to dozens of ecologists, ranchers, and conservationists, and immersed myself in the landscapes these animals inhabit. These travels formed the basis for my recent Island Press book, The Carnivore Way: Coexisting with and Conserving North America's Predators. In future posts, I'll share some of these species' stories and the astonishing lessons I learned along the way.