The ferocious wolverine is known for its ability to defend against predators several times its size and weight. But apparently there is little defense for the animal against rising winter temperatures, as federal wildlife managers have announced their intent to list it as an endangered species threatened by climate change.

Elusive and typically solitary except when breeding, wolverines are among the most rarely seen animals in the greater Yellowstone area, one of their last strongholds in the contiguous United States. A 2005-09 study found them in the southeast corner of Yellowstone and in the Gallatin National Forest, north of the park.