Bears are not true hibernators and do not really “sleep” for most of the winter.
They do, however, take a break from their constant search for food by slowing down in the winter months.
This allows them to conserve energy and survive on their stored body fat while they wait for spring to arrive.
There are some bears that may not hibernate at all depending on where they live as well as what time of year it is.
Bears Hibernating in New Brunswick
Bears hibernate when the weather gets cold. This ensures they will not expend any energy while they wait for spring.
Bears can sleep as much as twenty hours a day while hibernating. They start their sleep cycles in the fall when their body temperature and heart rate drop dramatically.
They then enter a stage known as torpor, where their body temperature drops even more and their metabolism slows down drastically to conserve calories.
Once in this state, the bear’s body temperature only varies about three or four degrees above or below normal body temperature compared to up to forty degrees during active times of year. Bears in the far north can go into hibernation early because of their cold environment.
Bears hibernate over a long period of time. The average bear spends 8-10 weeks of its winter hibernating.
Most bears do not truly hibernate though, as they are awake at least three months of the year, which is when they are eating and using up their fat stores.
When bears do become active in the spring, they lose weight and body temperature rapidly because their metabolism is so low from a deep sleep during the winter that it takes about one month to regain normal body weight for each pound of fat stored.
Bears do not really “sleep” for most of the winter, but rather use a form of hibernation called torpor. When bears enter this state, their body temperature and heart rate drop dramatically as well as their metabolism slows down to conserve calories.
Once inside this state, their body temperature only varies about three or four degrees above or below normal body temperature compared to up to forty degrees during active times of year. Bears in the far north can go into hibernation early because of their cold environment.
Bears do not truly hibernate while they are awake, but rather use a form of torpor called hypothermia during their active lives in the spring and during periods when food is scarce.
Bears can get active as soon as conditions permit in the spring, but they must first shed the weight they have gained during winter. The average bear loses between twenty pounds and forty pounds. This is more than twice their normal weight at this time of year.
In order to lose weight and store up fat, bears must eat a large amount of whatever food is available in late winter and early spring. They must also get out in the sun to warm themselves up so that they do not build up enough body fat to survive the cold months ahead. This leaves the population of bears vulnerable to hunters who are seeking food.
When bears emerge from their dens in the spring, they are hungry and will eat whatever food is available. This puts them in danger of being hunted and killed by humans, who may mistake them for the larger and more dangerous grizzly bear.
When bears emerge from their dens in the spring, they must also get out in the sun to warm themselves up so that they do not build up enough body fat to survive the cold months ahead. This leaves the population of bears vulnerable to hunters who are seeking food.
Scientists do not know exactly how hibernation evolved among bears or any other animal group.
