Did you know that bears don’t truly hibernate as most people think? According to the dictionary, hibernation is “the condition or period of an animal spending the winter in a dormant state.” To go further into this definition, you need to look at what dormant means, “having normal physical functions suspended or slowed down for a period of time; in or as if in a deep sleep.” Slowed down is the key phrase here.
As kids, we were told that bears hibernate by sleeping the whole winter. Did you know they are still a little active, just a bit slower at doing certain things?! Bears gorge themselves before winter since they won’t be able to find much food during the winter. They slow their movement down so they are not burning off too many calories and they won’t go hungry! They also lower their body temperature in order to help conserve heat, break down fat storage, and not eat or drink. But, if there is still plenty of food in the area, bears might not even hibernate at all!
Think about a dog sleeping at night. Compare that type of sleep to a bear during hibernation. When a dog sleeps, they get up and move around, switch positions, or just lay there awake. Bears will do the exact same thing by getting up, switching positions, and moving around.
What’s interesting is mother bears actually will give birth around 2 months into their hibernation period. The cubs will suckle off of mom and will stick with her in their den the whole winter! Cubs solely rely on mom and won’t leave the den until they are about 6 months old. At this time, they should finally be able to walk and feed on their own.
There are only a few critters out there that will fully shut down their whole body during hibernation in a deep sleep. An example of this is the Wood Frog. They will slow their heart rate down so much that it will freeze during the winter in the thick of the leaves. When spring comes the frog will melt and wake back up again to be fully functioning!
In true zoos and true sanctuaries, however, bears technically don’t need to hibernate at all. They are still going to be constantly fed throughout the winter but be a little bit more sluggish and sleep a lot more. Because we don’t want bears to be fed too much and gain a lot of weight, we try to give them that hibernation feeling to keep the animals healthy. We do this by feeding the bears twice a day during the summer and fall months in preparation for their “hibernation,” and then feed them once a day when winter comes.