Hibernation is a physiological process necessary for the survival of some species of animals. Bears are the most famous hibernating animals, but they are not the only ones.
Turtles, snakes, tree frogs, marmots, and insects are examples of other animals that exhibit hibernation. There is also a species of bird that hibernates when the climate is not favorable.
Some hibernate in the colony, and some hibernate in solitude. Researchers are studying the science of hibernation to find ways to help humans survive deep space travel, make operations safer, and perhaps even prevent disease.
Here is the index of the top ten animals that hibernate until the arrival of spring.
Table of Contents
1. Fat-tailed dwarf lemur
The fat-tailed dwarf lemur is the only familiar species that sleep during hibernation. It is also the only tropical mammal that hibernates. The fat-tailed dwarf lemur can rest in its natural environment for up to seven months.
During hibernation, this lemur lowers its heart rate from 180 beats to 4 beats per minute. Its breathing rate is also slowed, with only one breath every 10-15 minutes.
Endemic to Madagascar, the fat-tailed lemur hibernates during the dry winter season (April to October) when water is scarce.
These animals are also nocturnal, and their diet consists of insects, other small animals, fruits, and flowers. The lemur is called a fat-tailed lemur because it stores its fat reserve in its tail, functional during hibernation.
|Scientific Name||Cheirogaleus Medius|
|Hibernation||April to October|
2. Common Box Turtle
This turtle is one of the animals that can hibernate to adapt to its natural habitat. Since the turtle is poikilothermic, it cannot generate its body heat and instead receives heat from its environment. Turtles need to be bummed when cold weather sets in to conserve energy.
Like hibernation, brumation is a stage of inactivity in winter; however, unlike hibernation, brumation does not imply sleep. Box turtles usually dig a deep hole and brood for three to four months.
During brumation, these turtles will conserve their food reserves because the temperature outside will be low, making it difficult to maintain normal activities.
They will also slow the heart rate, stop the digestive system, and not move the body. The turtle’s heart rate drops to just 5-10 beats per minute. These animals fall asleep and do not open their eyes at all during hibernation.
Since their metabolism is slow, they do not need a lot of oxygen. They meet their needs by absorbing the oxygen present in the water through the skin, the mucous membranes of the mouth, and the cloaca.
The box turtle is found throughout the eastern United States and Mexico. The geographic area where they live requires most box turtles to hibernate for three to five months of the year.
|Scientific Name||Terrapene Carolina|
|Habitat||The Eastern United States and Mexico|
3. Alpine Guinea Pig
The alpine guinea pig can hibernate during the winter. These animals are found in central and southern European mountainous areas, generally at 800 to 3,200 meters above sea level.
Alpine guinea pigs have a combination of reddish-blonde and dark gray hair. This animal is also known as a master digger.
Alpine guinea pigs can spend up to nine months per year hibernating. The long duration occurs when the surrounding weather is suitable for a long hibernation. Before hibernation, these animals will eat large amounts of food to survive during a long sleep.
From that diet, a layer of fat is created on their bodies that allow alpine guinea pigs to survive prolonged periods of hibernation.
During hibernation, their heart rate decreases from 80-100 to 5-10 beats per minute, body temperature drops from 37 ° C to 2-3 ° C, and breathing slows down from 16 to 2 breaths per minute.
|Scientific Name||Cavia Porcellus|
|Habitat||Central and Southern Europe|
The hedgehog is the only one of the insectivorous family that hibernates. It is sensitive to climatic variations that herald the first colds and seasonal metabolic variations that warn it when it is time to take refuge in its den.
In October-November, the common hedgehog settles down to winter in a burrow or between the roots of trees.
Its dwelling usually has two exits, one of which is plugged with dry leaves. Having dragged moss and foliage inside the burrow, it lays everything in a loose lump, curls up, and sleeps there until April.
In April, upon awakening from winter hibernation, the mating season also begins, lasting until July-August. The body of a hedgehog cools down in hibernation. Still, its temperature never drops below 5 ° C.
During this period; the animal does not eat anything. Hedgehogs tend to wake up during hibernation every two to four days, or less often once a month.
|Habitat||Europe, Asia, New Zealand, Africa|
Not all snails hibernate, but when they do, it is a fascinating process. If the weather conditions are extreme, the snails hibernate.
In hot weather, this process is called aestivation, and in cold weather – hibernation. Since they have their shell for hibernation, they are ready for any weather conditions.
Before settling for hibernation, they empty their intestines and most of the water contained in their body. They are almost dehydrated when they decide to hibernate.
During hibernation, snails use mucus to seal their shells and protect themselves from the cold. The slime, once dry, is a fundamental protection that will allow the snails to hibernate for three to six months.
During hibernation, the snail will reduce its heart rate to a minimum. The snail’s heartbeat is relatively rare during sub-zero temperatures: one beat per minute in zero degrees.
Their energy consumption is almost zero during all this time, so they do not need to eat anything. Interestingly, in arid areas, where it rains very rarely, snails can hibernate even for years.
|Habitat||Wetlands, riverbanks, gardens|
|Hibernation||Summer and Winter|
6. Nuttall’s Nightjar/ Common Poorwill
Nuttall’s Nightjar is the only bird capable of hibernating. It is a small bird of about twenty centimeters that lives mainly in North America. Its very short and wide beak distinguishes it; it has enormous eyes and tiny clay feet.
Until the 1940s, scientists discovered that the little bird was hibernating. Nuttall’s Nightjar spends most of its day perched on a branch or hidden in holes, only to activate in the evening.
When winter comes, these birds will have difficulty finding food, so they settle for hibernation. Their weeks to months of hibernation takes place in their nest on the ground.
They lower their body temperature to five degrees during hibernation, and their daily energy consumption decreases by 93%. At the end of hibernation, the bird needs 7 hours to regain its average body temperature.
|Scientific Name||Phalaenoptilus Nuttallii|
The bat in winter enters a phase of inactivity in which its metabolism is slowed considerably. They usually hibernate in relatively warm places, such as caves and unheated houses.
In particular, there is a decrease in vital activities such as heart and respiratory rate in this phase of their biological cycle. In general, there is a significant lowering of the reactivity of the nervous system.
During this time, their heart rate can drop from 300-400 beats per minute to 10. Another good feature of bat hibernation is using the heat stored in their bodies to warm up again.
They lower their temperature from 38 to 17 degrees. Some bats at the end of winter can suffer from nerve disorders that can be fatal.
The actual hibernation usually begins when the external temperature drops below 10 ° C. During the immure period, the body temperature of the bats follows the ambient one. Still, if this falls below 0 ° C, the animals will wake up.
The hibernation of this animal occurs in groups, entire colonies of bats arrange themselves in neat and dense rows, making each other warm.
With the arrival of spring, hibernation ends. After hibernation, bats remember much more than other animals because of an unknown neuroprotective mechanism.
|Habitat||Caves, Cities, Forests|
8. The monarch butterfly
Here is a quite remarkable species of butterflies, both migratory and hibernating. From the start of autumn, this lepidopteran travels four thousand kilometers from Canada to Mexico.
It flies for two months, winning a second place among insects traveling the most significant migratory distance. It takes refuge in a forest three thousand meters above sea level, neither cold nor dry.
There, the butterfly gathers in a group on the pine branches. They sleep there by the thousands, offering a spectacle of golden reflections.
During the winter hibernation phase, as they have accumulated enough fat, they do not need to eat, but they do need to drink water.
So they are concentrated near areas where they can stock up. It is not until February that the monarch butterfly wakes up and mates. There are two types of generations in this Lepidoptera.
The first has a lifespan of between four and six weeks. The second, the Methuselah generation, occurs every four generations.
The Methuselah generation butterflies have a life expectancy of seven to eight months. It is the butterflies from the Methuselah generation that make the trips.
|Scientific Name||Danaus plexippus|
|Habitat||Southern California and Mexico|
Snakes will experience a form of brumation during the winter. Brumation is a hibernation term for cold-blooded (ectothermic) animals that cannot regulate their body temperature by metabolic activity.
Snakes are known to be susceptible to low temperatures. Therefore, those who live in temperate climates will hibernate during the winter.
Hibernation is essential for snake survival in cold weather. These snakes will find an isolated nest, which also helps the snake to avoid predators.
The length of time these animals hibernate can vary according to their location. Snakes that inhabit climates with low temperatures will spend most of their time hibernating.
Snakes in the northern regions can brood for several months, while only a few weeks in the southern regions. During brumation, snakes will undergo a period of wakefulness when they temporarily come out of their resting place to hydrate.
|Habitat||Forest, swamp, grassland, desert|
|Hibernation||September to December|
The lack of food and low temperature forced the bear to go into hibernation. The bear builds up sufficient fat reserves to pass the winter.
Its digestive tract becomes blocked with a plug of epithelial cells from the intestine, mucous secretions, hairs, and feces.
Bears don’t urinate or defecate during hibernation, and their heart rate drops abruptly from 55 beats per minute to nine.
The bear’s body temperature does not decrease during hibernation. Consequently, the bears can respond to danger quickly.
However, their breathing rate is only one breath every 45 seconds compared to the expected rate of 6-10 breaths per minute. The female can give birth during hibernation, and the cubs feed on her milk until she wakes up.
During hibernation, the amount of nitrogen in the blood increases rapidly, without damaging the kidneys or liver. The animal becomes resistant to insulin but does not experience fluctuations in blood glucose levels.
Depending on the weather conditions, the bear can hibernate for 3 to 7 months. After this long period of atrophy, the bear lost a lot of weight; however, scientists cannot explain how it does not lose muscle.
Around mid-April, the bear wakes up from hibernation. But although it finds itself lost during this period of not eating, it does not suffer muscle damage.
|Habitat||Forest, tundra, desert|
Be that as it may, with the beginning of spring and the arrival of warmth, all these animals come to life, awaken from a sound sleep, leave their warm winter shelters to start a new cycle of their life.
Once their hibernation period is over, their body functions resume as it was before hibernation.