Yes bears hibernate! Bear hibernation is truly a miracle of nature. They spend all year eating and when winter months approach, they all wander off to a cave to curl up in a big furry ball and snore away the entire freezing winter.
Everybody knows this. Even small children too young to attend to their own biological functions know how these wild animals make it through a period of harsh weather and food shortage. But beyond the fact that bears den up in winter, what do we really know of these lumbering slumber beasts and the secrets they keep beneath the ice and snow?
There are many theories that say that bears might not be ‘true hibernators’, but don’t sit the kids down and blow their fragile little minds with such theories, consider this.. “Bears are the best hibernators,” says Brian Barnes, director of the Institute of Arctic Biology at the University of Alaska Fairbanks. “Their body is a closed system. They can get through winter with only oxygen—it’s all they need.”
Using infrared cameras, surgically implanted electrocardiograms, and radio transmitters, Barnes and his team monitored hibernating black bears for three years. Their research showed that bears can drop their heart rate from 55 to 9 beats per minute and reduce their metabolism by 53% and accomplish this without compromising much on body temperature, a crucial fact that allows bears to be more alert than true hibernators.
Once hibernating, a black bear can doze for many months with a body temperature of 88°F or higher. Fat tissues break down and supply water and up to 4,000 calories a day; muscle and organ tissues break down and supply protein. Even though a hibernating bear drinks no water, it does not become dehydrated. In a 1973 study published in the American Journal of Physiology, hibernation expert Ralph Nelson and colleagues at the Mayo Clinic and Mayo Foundation found that the three hibernating bears they studied were in almost perfect water balance even after about 100 days of hibernation, during which they swallowed not a single drop of water.
However, a bear can be easily awakened during hibernation. So don't try and sneak into a bear den thinking it’s safe!! It is also important to note that not all species of bear will hibernate. Bears like the Asiatic Bear live in warmer climates where food is readily available all year long and there is no need to hibernate.
In February 2012, Swedish snowmobilers found a man who had been trapped under snow in his car for two months with barely any food. After he was rescued, local doctors suggested that he had survived by adjusting his core body temperature downward to about 88⁰F and keeping still, the same process which bears use to hibernate. Whereas some believe, those who practice meditation can also enter a hibernation-like state, on purpose. A professor of medicine at Harvard Medical School, has studied Tibetan monks in deep meditation and found that they can decrease their oxygen needs by as much as 64 percent and enter a deep hibernating state and after they revive, they recover completely and behave normally.
It therefore proves that humans too have tools for hibernation though these tools have not been evolved fully yet.
Photo by AlaskaFreezeFrame.
Indira Gandhi International Airport, Delhi
