Unseasonably Warm Temps Pull Yellowstone Grizzly Out Of Hibernation

Feb 12, 2015

Warmer-than-normal winter temperatures may be to blame for bringing a grizzly bear out of hibernation early in Yellowstone National Park. The park confirmed a report of a grizzly eating a bison carcass on Feb. 9 in the central part of the park in Wyoming.

Yellowstone National Park spokesman Al Nash says the park is using this grizzly sighting as a reminder to visitors that they could encounter bears -- even during winter hibernation months. Nash says recent temperatures have been about 10 degrees higher than normal, and this is the earliest a Yellowstone grizzly has been sighted in the last five years.

In a press release, park officials warn skiers and hikers to be on alert and "stay in groups of three of more, make noise on the trail and carry bear spray." Nash says animals emerging from dens could soon be looking for food, and are attracted to areas where elk and bison that have died over the winter.

But grizzlies coming out of hibernation early -- especially around warm weather -- isn't as rare as you might think.

"Every year, we see occasional bears that come out in the middle of winter," says U.S. Fish and Wildlife Service grizzly recovery coordinator Chris Servheen. "Sometimes they come out because they didn't go into the den in good shape and bears that are very hungry and starving tend to come out in the middle of winter and wander around."

Servheen says bears go through a big physiological change before going into hibernation, and it takes a couple of weeks to get their bodies back to normal once they come out of the den. He says it's not unusual for a bear to come out for a warm period and then return to the den at the next snow storm.

But the biologist says since this Yellowstone grizzly has begun eating, it's probably been out for a couple of weeks and is unlikely to go back into hibernation this winter.

Find Frankie Barnhill on Twitter @FABarnhill

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