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WSU research bears mark the changing seasons

Posted by scott.weybright | September 26, 2017

The bears at the WSU Bear Research,Education, and Conservation Center spent September gaining weight at a tremendous rate, up to 10 pounds or more each week, preparing for another winter and hibernation. Starting in late October, they’ll slow down their food intake to get ready for hibernation.

Two pictures of the same bear viewed from the top, taken at different times of the year. The picture on the left is the bear much skinnier after waking up from hibernation.
One of our WSU bears, on the left in March and on the right in October.

“Once they reach their hibernation weight, we’ll slowly reduce the amount of food they receive,” said Brandon Evans Hutzenbiler, manager at the WSU Bear Researcher, Conservation, and Education Center. “We try to mimic the decreased number of calories available to a bear in the wild as winter approaches. That along with less sunlight, colder temperatures and the bears’ natural rhythm all signal the bears it’s time to start hibernating.”

The bears will get one last small meal right around November 1, and then the staff will begin monitoring the bears from their computers or smart phones via video cameras.

“After that final meal of the season, we let the bears clean out their digestive systems,” Hutzenbiler said. “Once the cleanse is through, we can go in, clean up the dens, and put down straw bales for them to sleep on.”

Around this time of year, the staff recognizes several behaviors bears exhibit when preparing for hibernation.

“Some bears will start to drag grass, leaves, or small limbs around while others will begin to dig a den in the exercise yard,” Hutzenbiler said. “It’s a good sign that they’re preparing normally for the winter.”

Monitoring the bears on cameras throughout the winter serves at least two purposes: keeping a watchful eye on the bears’ wellbeing as well as recording their subtle changes.

“Their metabolism slows down so much, you can’t really watch them breathing in real time,” he said. “They only breathe eight to 10 times a minute, which is hard to see. But if we speed up the playback, we see the breaths much more clearly.”

The staff have a checklist for each bear and spend at least one hour monitoring them in real-time every day. In addition to their breathing, the staff notes the bears’ motions and movements.

Bears don’t sleep for the entire winter. They do wake up, walk around, re-arrange their straw bedding, get a drink of water, and go back to sleep. But they don’t eat anything at all, all winter.

“It’s really amazing when you think about,” Hutzenbiler said. “And it’s fun to watch the small, slow activity they do have.”

Sometime in March, the staff will notice an uptick in the bears’ activities, which marks their slow climb out of hibernation. Then the annual process begins again, for the bears and the staff at the Bear Center.