As the weather starts to cool down in the Northern Hemisphere, animals are starting to get ready to sleep the winter away in hibernation. Hibernation is a form of torpor, which is a state the animal enters to help it survive long periods with little food available. Torpor is a state where the animal's metabolism is significantly reduced, as well as the heart rate, respiration, and body temperature. Let's have a look at some of the cutest hibernators that we likely won't be seeing for the next few months.
Hedgehogs
One of the cutest pets available, the internet is full of videos of them on their backs. Hedgehogs are actually predators, mainly feeding on insects but also taking frogs, berries, snails, even snakes and mushrooms. They are native to Europe, Asia, and Africa and are commonly kept as pets today. They are easily recognised by their spiny protection. During hibernation, their body temperature can drop to about 2 Celsius (36 F). They will dig their burrows in old sheds, under tree trunks, or even in wood piles, so make sure you check your wood before putting it on the fire.
Bears
Probably the most famous hibernators, both the black bear and the grizzly bear hibernate in the winter. The grizzly, being significantly larger than the black bear, obviously needs to find a larger den in which to spend the long winter.
Bumble bees
There are about 250 species found mainly in the northern hemisphere. Most of them are social, but not quite as social as their cousins, the honey bees. Some of the colonies grow to as few as 50 workers. It is only the queens that hibernate, as the males and workers all die before winter begins. An interesting thing about bumblebee queens is that they can spend most of their time as adults hibernating.
Marmot
Considered large ground squirrels, there are 15 species of marmot throughout the world. Native to North America, Europe, and Asia, some marmot species can exceed 11 kg (24 lbs) in weight before going into hibernation. Typically, marmots live in rock piles and are found in mountainous regions, although there are a few species, like the groundhog, that live on prairies and grasslands.
Poorwills
Image by Dominic Sherony, used with permission
Apart from being cute, Poorwills are interesting in that they are the only species of bird that is known to truly hibernate. Other species of birds will enter torpor, like some species of hummingbirds, who have to enter torpor to survive the night. However, the Poorwills are the only species of bird that is known to hibernate for long periods of time. The name Poorwills literally means "the sleepy one" and some Poorwills will enter hibernation for several weeks to a few months depending on the temperature. They use up their fat stores, built on the insects they caught prior to hibernation.
What do you think are the cutest animals to enter hibernation? An honourable mention for this list is the wood frog. It wasn't added since most people wouldn't consider it cute, but it has some incredible adaptations for hibernation that you can read about by clicking here.