Visitor Counter

hitwebcounter web counter
Visitors Since Blog Created in March 2010

Click Below to:

Add Blog to Favorites

Grizzly bears, black bears, wolves, coyotes, cougars/ mountain lions,bobcats, wolverines, lynx, foxes, fishers and martens are the suite of carnivores that originally inhabited North America after the Pleistocene extinctions. This site invites research, commentary, point/counterpoint on that suite of native animals (predator and prey) that inhabited The Americas circa 1500-at the initial point of European exploration and subsequent colonization. Landscape ecology, journal accounts of explorers and frontiersmen, genetic evaluations of museum animals, peer reviewed 20th and 21st century research on various aspects of our "Wild America" as well as subjective commentary from expert and layman alike. All of the above being revealed and discussed with the underlying goal of one day seeing our Continent rewilded.....Where big enough swaths of open space exist with connective corridors to other large forest, meadow, mountain, valley, prairie, desert and chaparral wildlands.....Thereby enabling all of our historic fauna, including man, to live in a sustainable and healthy environment. - Blogger Rick

Subscribe via email to get updates

Enter your email address:

Receive New Posting Alerts

(A Maximum of One Alert Per Day)

Saturday, February 1, 2014

With there being a lot of speculation taking place about why Black Bears around the Country are seemly more active this Winter and not hibernating,,,,,,,,,,,,, comes this report from the Lake Tahoe region of California revealing that global warming is seemingly not the reason for Bruin activity during winter months........Calif. Dept. of Fish and Wildlife studies reveal that 5 to 15% of Black Bears stay active during typical winters and this winter the pattern continues........However, where warming temperatures lead to drought, the quantity and variety of foodstuffs available to Bears get compromised.............The scientific community here is speculating that where it has been particularly dry, Bears might come out of their dens more frequently to seek out a winter meal and a drink...................Unlike Bears, when small mammals (squirrels, chipmunks et al.) hibernate, their heart rate and body temperature drop radically, toeing death's doorstep without actually stepping over, and stay that way for several months............. Black bears, on the other hand, have a hibernation cycle that is much less extreme.............: They crank down their metabolism, heart rate, and body temperature just enough to get seriously lazy, but are still with it enough to be "perfectly capable of shaking off their lethargy and coming out of their caves for some fresh air and a meal

No, Climate Change Is Not Waking Bears From Hibernation

No, Climate Change Is Not Waking Bears From Hibernation

| Thu Jan. 23, 2014 10:33 AM GMT
bear with trashA black bear hunkers down near a pile of garbage in Sacramento last fall. 
Last week, a rogue black bear made a cameo appearance for skiers at the Heavenly Mountain Resort near Lake Tahoe. The month before, a 260-pound male bear had to be put down by wildlife officials after breaking into several cars and a home in the same area. The spate of run-ins comes as California's brutal drought lingers on, with snowpack in the Sierra Nevada at a fifth of its normal level, leading several news outlets to suggest that balmy conditions have led bears here to awaken prematurely from their annual winter slumber.
That's a nice hypothesis, but according to the California Department Fish and Wildlife, there's nothing to it. Five to 15 percent of the Tahoe area's 300 black bears stay awake every winter, said CDFW biologist Jason Holley, and "we don't have any evidence to support that there's any more this winter." In fact, Holley said, the last few months of 2013 saw fewer bear complaints than average.
SF Chron front page
The front page of a recent San Francisco Chronicle. There's no evidence that more bears are awake this year than in an average year, officials said. Clara Jeffery/Mother Jones
So why all the hullabaloo? Holley's guess is that the drought cut down supplies of the bears' natural food sources—mainly grass, berries, and insects, although they'll eat just about anything—forcing those that are normally awake anyway to wander further afield, i.e., onto your ski slope or into your backyard. Not that the bears mind much.
"They are very adaptive and very mobile, so they will usually be able to take care of their daily needs in a drought situation," Holley said. "But then they're coming down to the lake to drink a lot, coming down for food. If the drought persists, it greatly increases the odds of a negative interaction with people."
What motivates some bears to stay awake while others hibernate is still somewhat of a mystery to scientists, according to Roger Baldwin, a wildlife specialist at the University of California-Davis who has conducted extensive research on bear behavior. When small mammals (a squirrel, say) hibernate, their heart rate and body temperature drop radically, toeing death's doorstep without actually stepping over, and stay that way for several months. Black bears, on the other hand, are much less extreme: They crank down their metabolism, heart rate, 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, so rousting them is neither uncommon nor difficult.

Bears often scout out multiple den sites in advance of winter and move between them if one gets disturbed; in warm years, that could happen if snow melts into the den ("They're not gonna sit there in a pool of water," Baldwin said), or for any number of non-weather-related reasons. But generally, temperature has a much smaller influence on hibernation behavior than the availability of food; in a very lean summer, bears will build up smaller fat reserves and not be able to hibernate for as long. But they are such proficient omnivores, Holley said, that even a drought like this year's probably isn't enough to majorly disrupt their hibernation habits, unless it continues for several more years.
But drought does increase the risk that bears that do find their way to garbage cans, cars, and other food sources from people will, like Yogi, get too comfortable raiding peoples' pic-i-nic baskets. That's why it's especially important to keep these things on lockdown, away from bears, Holley said.
"It's everybody's responsibility to help keep bears wild," he said. More on how to do that here.

No comments: