One of the most confusing concepts to wrap my own brain around when I think of the capabilities of animals is the action of hibernating. Did you know some animals can hibernate, meaning they don’t wake up, drink, eat or go to the bathroom over as long as a 6 month period! If you’re like me and you just read that, you’re probably asking yourself how that is even possible without resulting in something as serious as death?
In researching this specific topic, I found myself to become more and more fascinated in the process of hibernating and what goes on inside the bodies of these animals that allows them to perform such an incredible thing. In many animals, hibernation lasts over the course of a time when their food source will be unattainable, such as harsh winters. In these hard times, these older animals will usually go out and collect as much food as possible and store it in these newly dug dens. Now if you’re wondering why they collect food when I said some animals don’t wake up to eat, sleep, or drink at all during this long period of time, that’s because the key word was some. Specific kinds of bears such as Grizzly and Black Bears don’t wake up whatsoever during this time will most other kinds of animals who hibernate do.
When these animals wake up it is usually because their bodies send a signal that they are running low on food and an impulse wakes them up out of their deep slumber and quickly take a bite to eat and a sip of water and then back to bed they go.
When these animals hibernate there are brown fat and regular white fat. This special kind of brown fat creates patch like surfaces on organs such as the heart that generate extra heat, as these animals are usually hibernating during a harsh winter. This brown fat that these animals are able to produce is a key function in the reason hibernation is possible. During hibernation, a heart beat can get to about 80-4 beats per minute. If one of us was to stumble upon a bear in hibernation we would most certainly assume it was dead.
When the hibernation period is over and the animals wake up, this is primarily why they store up so much food during this time. Can you imagine waking up after 7 months of a deep sleep and how hungry you would feel? In fact, most animals who hibernate need to come out of their burrows asap to begin to scavenge for food again, as this time they have lost a giant amount of their body fat, which in turn helps them to stay warm.
Sources:
https://qph.is.quoracdn.net/main-qimg-03ad8ad38f980772a9455854046f8596?convert_to_webp=true
I once wondered about this question as well, because I hated winter and I wanted to sleep through it. It is amazing what the brown fat can do to keep animals in sleep. If human can do this, maybe we can then live longer and hibernate through space travels. One thing that I am curious about is how they can sleep that long. You mentioned they can sleep up to seven month and I can hardly imagine that. Why wouldn’t they wake up? And what wakes them up when winter passes?