Top 10 Bear Hibernation Questions Answered
It’s really important that we give bears as much space as possible. It’s springtime, and it’s time to keep bear safety in mind because hungry bears are now clambering out of hibernation. But what exactly is hibernation and why do they do it?
Top 10 Bear Hibernation Questions Answered
1) Why and where do bears hibernate?
Bears have evolved to hibernate because it’s their best chance to survive the food scarcity each winter. Their dens are found in wooded areas, within hollowed-out trees, beneath piles of brush, or in anything their environment offers such as a snow den which is basically a snow covered snow drift.
2) What is the difference between hibernation and walking hibernation?
Stage 1— Hibernation is called “winter lethargy” or torpor – it’s also referred to as a form of “suspended animation”. The bears are in an inactive sleep-like state. During hibernation, body temperature is lower than normal, their heartbeat and breathing slow down tremendously. They use up to 4,000 kcal per day, mainly body fat, and they do not eat, drink, urinate, or defecate. They reduce oxygen consumption and metabolic rate to a little as 25% of summer rates and breathe once per 15 to 45 seconds. However, they aren’t asleep the whole time, they may get up and walk around their dens. Mothers (Sows) on the other hand, maintain near normal body temperature (high 90’s Fahrenheit), ingest their cubs’ urine and feces. They also lick up drops of meltwater, eat snow and icicles, urinate, and defecate during hibernation.
Stage 2—Walking hibernation is the 2-3 weeks, bears have emerged from their dens but they are hungry and they immediately begin to search for food, they still sleep a lot and don’t roam very far. There is usually plenty to eat when the receding snow reveals vegetation rich in nutrients. They also will find winter kill – deer, elk, moose or anything else that may fancy a bear’s taste buds. During walking hibernation, bears voluntarily eat and drink less than they will later during normal activity. They also excrete less urine, nitrogen, calcium, phosphorus, and magnesium.
Stage 3—Normal activity typically lasts from green-up in spring to the onset of hyperphagia in midsummer or fall, depending upon region. During this stage, bears with unlimited food eat 5,000 to 8,000 kcal per day. If they are denied water and food during this stage, they cannot duplicate hibernation responses. Instead, they become dehydrated, utilize muscle for energy.
3) What triggers hibernation in bears?
Hibernation is triggered by decreasing day length and hormonal changes in an animal that dictate the need to conserve energy. Before hibernating, animals generally store fat to help them survive the winter.
4) Do hibernating animals sleep the whole time?
Although Bears hibernate during winter, they aren’t sleeping the whole time. Hibernation for bears simply means they don’t need to eat or drink, and rarely urinate or defecate (or not at all). Bears use up much of their body fat during hibernation. However, they keep most of their muscle and bone mass. There is strong evolutionary pressure for bears to stay in their dens during winter, if there is little or no food available.
5) What happens if you wake a hibernating bear?
If you were to wake up a hibernating animal midwinter, you would be effectively killing it. It would use up so much energy warming itself up in order to awaken that it would have no chance of making it to spring even if it could re-enter hibernation
6) What time of year do bears come out of hibernation?
When the weather grows cold and the food supply finally dries up, they will retreat to their winter dens. Males bed down around mid-December and emerge in mid-March; females, which give birth during the winter and stay with their cubs for two years, remain in their dens longer, from late November to mid-April
7) Are the mother and cubs first out of hibernation?
No, the first bears out of the dens are the dominant male bears, then the lone bears or “subadults” and finally female bears with cubs will begin to emerge mid-April. They have been in a state of really reduced physiological function for five months. So, their metabolic rate, their breathing rate, their heart rate, everything has slowed right down.
8) How do I avoid a bear that has just come out of hibernation?
- In bear habitat, avoid trails with thick bush, tight corners and hills.
- Watch for fresh bear signs. If the signs look like they were made recently, quickly and calmly leave the area. Signs of bear activity include:
- Fresh carcasses
- Overturned rocks
- Scratched logs
- Torn-up ant hills
- Avoid areas with typical bear food sources. These include berry patches, grain fields, garbage pits, beehives and anywhere you can see an animal carcass.
- Watch for crows, ravens, magpies or jays. These birds often indicate the presence of an animal carcass that may also attract a bear.
- Be alert when in wildlife travel corridors. Rivers and streams, trails and access routes, are common travel corridors for wildlife, including bears. Be cautious when you are in these areas.
- Make noise. Talk loudly, sing or let out occasional warning shouts. This will alert bears to your approach so you are less likely to cause a surprise encounter. Remember that other sounds, such as flowing rivers and streams and strong winds, can drown out the noise you make. Be extra noisy at these times.
- If you hike with a dog, or children – keep them close. Keep your dog on a leash.
- Avoid being out at dusk, night or dawn. Although bear encounters can happen at any time of day, bears are most active at dusk, night and dawn.
9) What do I do if I come across a bear right out of hibernation?
If you run into a bear, stop where you are and remain calm. Get ready to use your bear spray. Do not run away, keep yourself and the bear safe by backing away slowly. If you remain calm as you slowly back away, the bear will likely not see you as a threat.
10) What if I see a bear by the road?
Slow down but maintain a respectful distance. DO NOT STOP FOR A SELFIE. For the bear’s sake, do not stop, do not stress it, let it forge and feed at its will. Be aware of traffic. Remain in your car. And never, ever feed a bear.
At AiM Environment, we understand having detailed knowledge and understanding of the physical and environmental setting is critical to a project success. Our main focus when working with clients is to mitigate environmental risk while ensuring economic feasibility. Our AiM Environment team has proven scientific and engineering expertise to work collaboratively with you to develop a cost effective strategy to satisfy your project’s specific objective.