When Predators Attack (Each Other): Researchers Document First-known Killing Of A Wolverine By A Black Bear In Yellowstone

Scientists Kristine and Bob Inman, while tracking the wolverine as part of a WCS study of these rare carnivores, discovered that the animal's radio collar began emitting a "mortality signal," indicating it hadn't moved in several hours. They later found the wolverine's carcass, showing clear evidence that it had been killed by a bear. Nearby, they discovered the carcass of an elk, along with additional evidence that the wolverine had attempted to drag it away from the bear, thus instigating the fatal encounter.

"This incident, where a wolverine decided to battle it out head-on with another carnivore ten times his size, substantiates the species' ferocious and intrepid reputation. The center of the conflict, an elk, may have been a "winter-kill," frozen in the snow until discovered by the bear emerging from its winter hibernation," said Kristine Inman.

The wolverine was one of a number of individuals WCS researchers have been tracking in the Greater Yellowstone Ecosystem for the past two winters. Researchers are investigating threats to wolverine populations to provide state and federal agencies with data about survival and reproductive rates, travel corridors and habitat use. The degree to which increasing development and back-country recreational use in mountainous areas threatens wolverine populations is unknown. Understanding threats to this rare and elusive animal is essential to its conservation.

Last month, another team of WCS researchers discovered another carnivore oddity, when they learned that a mountain lion they were tracking in Yellowstone National Park had been attacked and killed by a pack of wolves.