Hibernation: What Is It And What Animals Practice It

When winter comes, many animals take refuge in a cave or inside a tree and sleep for months. That process (roughly) is hibernation. In this article we will tell you how they manage to spend so much time without waking up or eating and which animals practice it.

What is hibernation?

Hibernate is a capacity that some species possess and that allow them to spend the winter without having to “worry” about food or bad weather conditions. During this process, the body temperature drops to very low levels, as does the respiratory rate.

Throughout the duration of hibernation (days, weeks or months), the body uses the energy reserves that have been stored during the warm seasons. While it is more prevalent in warm-blooded animals such as bears, it can also be carried out by cold-blooded ones, such as crocodiles.

In the case of mammals, they should be prepared in advance. When the ambient temperature drops, they fall asleep, causing a radical drop in heart rate and respiration. Organic temperature drops excessively.

At first glance it seems that the animal is dead, because even to the touch the skin is cold. In addition, in many cases they can be tried to wake up or make a sudden movement without making them “come to themselves.”

The so-called “winter dream” is a great enigma for scientists and experts in zoology. Because it is more than sleeping soundly. Digestion stops, they do not have physiological needs such as urinating or defecating, they are not thirsty, etc. For hibernation to be successful, the animal must have increased its lipid stores during the summer and part of the fall. When you wake up, you will have lost weight and will not have much energy.

What animals hibernate?

The state of dormancy or winter lethargy reduces the heart rate by 80%, the respiratory rate by 50% and the body temperature by up to 5 ° C. When spring arrives, everything “returns to normal” and soon after the mating season begins.

Not all animals have the ability to hibernate. Only those who live in a temperate environment with a marked winter season do it. Among the species that hibernate each year we find:

1. Bears

Large, omnivorous (except for polar, which is 100% carnivorous), with short ears and a body completely full of hair, the bear is perhaps the most “popular” species in terms of hibernation. This plantigrade that can walk on four or two legs can sleep all winter in a cave.

2. Earthworms

Although it may attract our attention, the “bugs” also hibernate. The best known are those of earth, reddish in color, which dig holes in the ground and feed on food scraps or insects to later transform into compost. When the temperature of the earth is low, the worms reduce their activity (which is basically eating and reproducing) to a minimum.

3. Squirrels

They come in different colors and sizes, all with their furry tail and large teeth. For several weeks before winter begins, the squirrels already prepare by accumulating nuts and other fruits that fall from the trees with the arrival of autumn. They can store hundreds of supplies in their homes, mostly in the trees.

4. Lizards

The process of reptiles is called Brumation, and it is similar to the hibernation of mammals. In this case, they experience an under-freezing of their blood, fluids and even cells. In this way they can survive sub-zero temperatures.

5. Bats

The hibernation period for these flying mammals is 183 days. They carry out this process not only due to low temperatures, but also due to the scarcity of prey (mainly insects). In this state, body temperature drops and physiological and metabolic changes occur.

Before doing so, they eat a good amount of food in order to save fat. They may wake up periodically (every 10 days) to defecate and urinate, or move to another more suitable place.

Main image source: Eduardo Javier Maldonado Acevedo