why do bears hybernate?
436147
Hybernation is a particular form of torpor, a state of reduced metabolism and low activity.  In this the body temperature of the animal drops almost to ambient temperature but periodically spikes up to its normal value.  The reason is indeed to preserve energy in a time when food resources are scarce.  Bears thereby can survive on a very low metabolic rate.  This way they can manage to spend the winter months without having to find the otherwise needed amount of food.\n\nFootnote:  It is NOT a state of sleep these animals are in, but indeed a state of extremely reduced metabolism and activity.  Different from other forms of torpor is here that the animal's body temp now and then spikes up, in other word, that the animal now and then indeed metabolizes.\n\nHope that helps.
883044
the stomach acid of a bear is unbelievable.they digest bones with no problem.
339803
Sloth bears, like most wild creatures, seek foods which will return the highest nutritional value for the least expenditure of energy. Seasonal availability and geographic location are the biggest factors determining the primary food sources of sloth bears. \n\nWithin the tropics, termite and ant colonies are abundant and stable food sources. Sloth bears have adapted to become specialized termite hunters. The bears will dig into the hard tall pillars where the termites live. They then insert their muzzle to suck up the termites and their larvae. The noise made by this activity is very loud and can be heard up to 180 meters (200 yards) away. \n\nSloth bears will also climb and shake fruit trees to obtain food. Honey is also a source of nutrition for the bears, as are ants, berries, cultivated sugarcane, corn, cultivated yams and the fleshy flowers of the Mohwa tree. \n\nWhile not known to be very predatory in nature, sloth bears will eat virtually any carrion which they may discover. \n\nSloth bears prefer to feed during the night but will feed at any time of the day as necessary.
370357
They group together within their nest/mound and go into something called "diapause," which is the insect equivalent of hibernation. Their bodies freeze and they just shut down and become active again once the temperatures reach a warm enough level.
394462
polar bears are threatened by the spread of hormone-disrupting chemicals and global warming. This affects the polar ice edge ecosystem, the habitat of walrus, seals and penguins, as well as bears. \n\nMORE INFO ON THE LINK BELOW :)
1170597
It takes time to transfer the thermal energy to the snow.  Snow also has an insulating effect on lower layers of snow, making it difficult to transfer heat there, making snow more persistent than would be expected.
125241
Polar bears don't have to defend themselves from anyone or anything other than human hunters, and even then often the polar bear can get the upper hand.  Polar bears tend to live at the edge of the floe ice, so they can easily swim away from anything they want to avoid.\n\nPolar bears really can't defent themselves from the main things that are really endangering them, mostly the melting polar ice cap.
212442
Koala bears.  \nThey extract moisture from leaves and never touch water.
902928
"Bears don’t pee or poop when they hibernate. Their bodies recycle or simply stop making what normally needs peeing out every day"
605091
Frogs hibernate in burrows or under leaves or bury themselves in mud. Their organs contain a high concentration of glucose which prevents the frogs from freezing.
953744
They fatten themselves up in summer/autumn. They may grow thicker fur but the most common coping mechanism is hibernation in a sheltered location where they are not exposed to the elements.
1073753
Yes, when there is a decrease in barometric pressure, your body becomes more relaxed and it is easier to sleep. The barometric pressure is decreased on rainy, gray days. This is also one of the factors that contributes to the hibernation of bears.
552465
To conserve body heat and energy.
795780
some of them might hibernate. hibernation allows some small mammals to reduce their metabolism during times of scarce resources, such as winter. they accumulate body fat for a while, then it's like their system «shuts down»: their body temperature decreases, their pulse too, and they might breathe as few as 1 to 10 times a minute!\nhibernation is a real advantage because, when it's cold, it would take a lot more energy to keep normal body heat, consuming more nutrients, when, in fact, it's the time of year when it's more difficult to feed!
290498
Yes you can, but during hibernation the system consumes more resources! This is the only problem!
1045189
Hibernation is a state of regulated hypothermia, lasting several days or weeks, that allows animals to conserve energy during the winter. During hibernation animals slow their metabolism to a very low level, with body temperature and breathing rates lowered, gradually using up the body fat reserves stored during the warmer months. Some hibernating animals stir as often as once a week; others sleep throughout the season. Some reptile species are said to bruminate, or undergo brumination, but this is just another term for hibernation, usually in the context of an induced hibernation in captivity necessary to reset the animal's biological clock for a new breeding season.
882444
They can hunker down in deep grasses. The snow and grass act as insulation keeping them warm.\n\nWhat's cooler (pun intended) than this is to look at tree squirrels, who have nests high in trees open to the blowing wind. Even they stay warm while being that exposed. The nests help trap body heat while breaking the wind.\n\nNature has some remarkable methods to keep animals warm.