Lessons in hibernation for the little Rescued Bear

How small was that bear in the tree up Limberlost way?  Well, here's a shot of Billie Bear in the dog crate she borrowed to travel to the Aspdin Valley Wildlife Sanctuary.

That's one pretty small bear. The estimate was that she was just 20 pounds (or, the way we measure weight here, about 1.25  Napsters )

CBC recently ran a really interesting piece on bears and how they hibernate -- a study at the University of Alaska took a serious look at hibernating bears. The bears were what is termed 'nuisance bears', which simply mean they were where people don't want to see them, usually in garbage bins or backyards checking out birdfeeders. Nuisance bears, created by people being careless with food, are dangerous, and as the old adage goes, To feed a bear is to kill a bear. They are frequently shot.

Five of them in Alaska, however, got lucky.  The bears were trapped, taken to the University, and outfitted for the study on hibernation.

The researchers gave them artificial wooden dens that were dark, cold, and snug, just the way bears prefer, and so far out into the woods that lead researcher Tøien could reach them only on skis. They fitted the bears with sensors to record their temperature and heart rate, and the dens with infrared cameras and other sensors that monitored the bears' movement, oxygen consumption, and even their snoring.(while they don't move much, hibernating bears sure do snore!)

Unlike ground squirrels and other small hibernators, whose body temperature drops almost to freezing during hibernation, bears' body temperature drops by only about 6°C. Yet their metabolism and oxygen consumption dropped by 75%, suggesting that another mechanism is involved in conserving their energy. This number was far far lower than anyone expected. (except the bears)



The bears made a lot of effort to conserve this much energy. While sleeping, they took only one or two breaths per minute. As they inhaled, their hearts did a quick flutter and then stopped until the next breath—resulting in a heart rate of about four beats per minute. Finally, the researchers found that during the few weeks before and after going into hibernation, the bears enter an intermediate metabolic state: wandering around and eating like normal but with lowered metabolism.

Maybe little Billie Bear didn't quite understand this complicated concept -- or more likely, she simply didn't have enough body fat to get her through the long winter sleep.  Either way, she -- like the Alaska bears -- got a little lucky.  At the Sanctuary, she'll find food, and snug places to sleep, and spring will be here soon.

As well, the folks at Aspdin Valley are used to wild animals, and understand how to work with them without socializing them to people, so there's a good chance that little Billie Bear will one day be able to go back to being what bears do best -- living in the wild, being a bear.