The weather isn't to blame for bears staying awake during winter.

The drought is a wake-up call to water users all over California, except perhaps its bears. The San Francisco Chronicle suggested in a front page article recently that the winter is too warm for bears to sleep. However, wildlife experts quoted by Mother Jones said the weather isn't to blame.

What motivates some bears to stay awake while others hibernate is still a mystery to scientists, according to Roger Baldwin, UC Cooperative Extension specialist in the Department of Wildlife, Fish and Conservation Biology at UC Davis. He has conducted extensive research on bear behavior.

When small mammals hibernate, their heart rate and body temperature drop and stay low for several months, the article said. Black bears, on the other hand, are much less extreme: They crank down their metabolism, heart rate, 

Roger Baldwin, UC Cooperative Extension and UC Davis.

and body temperature just enough to get seriously lazy, but are still with it enough to be "perfectly capable of taking a swipe at you if you crawl into the den with them," Baldwin said. Waking them up is not uncommon or difficult.

Generally, temperature has a smaller influence on hibernation behavior than the availability of food. But bears are such proficient omnivores, said California Department of Fish and Wildlife biologist Jason Holley, that even a drought probably isn't enough to disrupt their hibernation habits, unless it continues for several more years.

(This article, by Jeannette Warnert, is reprinted from the UC ANR News Blog, Jan. 23, 2014, http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=12677)