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Hibernation is a crucial concept for the survival of animals through harsh weather conditions. And whenever we hear “hibernation,” our brain shouts “bears.”
But bears are not the only animals hibernating, and you will be surprised to know how many animals struggle through adverse weather to survive.
So, here is the surprising list of 15 animals that hibernate along with the Bears.
15 Hibernating Animals: A Complete Guide
Most animals hibernate in colder weather when food resources and warmth become scarce. They enter into a state of temporary dormancy until more tolerable weather arrives.
Here is a list of some animals that hibernate to survive.
1. Box Turtles
Box turtles are cold-blooded hibernating animals. Their hibernation period generally spans from 3 to 4 months.
These are some of the lucky hibernating animals that do not have to worry about their hibernation spot much. All they have to do is crawl to some safe corner space and hide inside their shell until the cold weather has toned down.
During the time inside their shell, these turtles come out once or twice for water but then go right back in. Since they have cold blood, box turtles can not produce their body heat, which compels them to hide in their shells in the winter season.
They used stored oxygen and energy reserves during their hibernation and tried to fulfill their minimal needs without using their lungs.
Turtles, like freshwater turtles, are some of the animals hibernating actually in the water. Freshwater helps them to maintain a stable body temperature.
2. Fat-tailed Dwarf Lemurs
Native to the western coast of Madagascar, the fat-tailed dwarf lemur is one of the only known cold-blooded animals hibernating in this area.
These animals hibernate for up to seven months every year when the leaves and fruits they feed on are not easily available. Fat-tailed dwarf lemurs hibernate in the hollow of trees with their friends and family for extra warmth.
During their hibernation period, these lemurs alternate between REM sleep and a state of inactivity to conserve their energy and reduce metabolic activities. They are the only known animals that fall fully asleep during their hibernation.
Prior to hibernation, the tails of these lemurs start getting thick as they start storing fat in their tails for their hibernation periods.
Unlike other animals, fat-tailed dwarf lemurs do not control their body temperature in hibernation, and their body temperatures can fluctuate with the outside weather. So they must ensure that the tree they are hibernating in is well insulated.
3. Ground Squirrels
The first thing that we need to understand is that not all ground squirrels hibernate.
But some of the ground squirrels, like the ones living subfreezing state of Arctic ground, hibernate to protect themselves from the harsh winter months.
These are the only known warm-blooded hibernating animals to live through the subfreezing state of their body temperatures.
Their hibernation period varies from 7 to 9 months until spring arrives, and they choose their hibernation spot very wisely, as they prefer to stay close to warmer places. So, the ground squirrels choose underground homes as their hibernation spot as Earth offers higher temperatures than their surrounding environment.
These underground places are strategically structured with hollowed-out tunnels and different rooms. They have separate areas for storing food, living, and even urinating.
Ground squirrels go into a lighter form of hibernation, generally known as torpor, where instead of deep sleep for long times, they may wake up and go out to forage during the warmer days.
4. Garter Snakes
Most commonly found in North America, Garter snakes are often kept as pets as they are relatively harmless and are not dangerous to humans.
They are cold-blooded animals that hibernate to safeguard themselves from low winter temperatures.
Garter snakes hibernate in groups. Their numbers can range from 10 to 10,000 in one group to prevent getting a low body temperature.
These snakes generally look for meadows, woodlands, and grassy areas to make their dens for winter. So, they travel long distances before winter to get to the right place and then build their dens.
The hibernation period of these snakes ranges from 5 to 6 months. During this period, these snakes do not eat anything, as their body temperature is too low to digest anything, and they just absorb the moisture from their skin to stay hydrated.
Like another hibernating animal, Garter Snakes also have their fat reserves for the dormant season, where they sleep curled up in a group.
Expert Insights into How Some Snakes Choose their Winter Dens?
Andrew Green, Chief Technology Officer at EcoMotionCentral.com ( a platform dedicated to educating and empowering individuals to make a positive impact on the environment by transitioning to electric mobility and reducing their carbon footprint while contributing to a cleaner and greener world) describes:
“Snakes are quite strategic when [it] comes to selecting a winter den or hibernaculum. They often look for a spot that offers protection from the cold and predators.[This] can be underground burrows, rock crevices, or even man-made [artificial] structures. The location [needs] to be below the frost line to ensure a stable, above-freezing temperature.
Snakes [are also known to] return to the same den year
after year, sometimes traveling considerable distances to get there.
During brumation, a hibernation-like state for cold-blooded animals, [snakes] undergo physiological changes. They can absorb moisture through their skin, which is crucial since they don’t eat and rarely drink.
Their metabolism slows dramatically, reducing their energy needs. This adaptation is vital for survival during the months when food is scarce.
Snakes’ ability to hunker down and essentially ‘turn off’ their energy demands is a remarkable adaptation that allows them to thrive in environments where winters are unforgiving, [I]believe.
Their seasonal resilience is a testament to the incredible versatility of reptiles.”
5. Prairie Dogs
In central and western United States, Prairie dogs live in intricate underground colonies, also known as prairie dog towns.
These animals also get into light hibernation. That means they wake up from their hibernation in the daytime when the temperature is warm and gather food. When the temperature falls, they come back to their hibernation spots.
In low temperatures, the heart rate of these animals drops significantly, and their breathing slows, making their metabolism shallow. So, they return to their underground abode to conserve energy.
These are cold-blooded animals that hibernate for around six months.
Though they live in underground places the whole year long, they start getting into true hibernation around the colder seasons when their body temperature decreases.
Bumblebees, the sound of the summer, is one of the most surprising hibernating animals.
The Queen bee of every colony broods several worker bees during the spring and summer. After that, she produces new queen bees and/or male bees. Males and the other queen bees leave the nest to mate with other bees, and the queen bee goes into hibernation.
These queen bees hibernate just along with the time-climatic temperature plummets. They dig into well-drained soil on the north-facing banks to make it their hibernation spot while all the other males and worker bees die.
The hibernation period of the queen bee spans from 6 to 7 months until spring arrives.
Generally, the queen bee fills her hibernation spot with pollens and her other eatables before the hibernation so that she can get into deep sleep without worrying about her health.
Ground bees and bumblebees hibernate similarly, but honey bees do not hibernate. They stick together with their colony during the winter, stay warm, and survive collectively with the food they had stored during warmer climates.
Bats are of warm-blooded animals that hibernate, but their hibernation is chosen.
Not all bats hibernate; some choose to migrate to warmer places when the temperatures drop. However, some species of bats decide to stay and hibernate.
Although generally, bats tend to hibernate in dark, isolated places that are somewhat damp, they also don’t mind sharing their place with humans.
Some bats hibernate near houses in old barns, closed attics, hollow trees, and abandoned factories during the colder seasons. Bats huddle in a place together and get into deep sleep or torpor.
Bats generally hibernate in groups when temperatures drop. They sleep upside down in a densely packed area and tend to return to the same place for hibernation in the next year.
The hibernation period of this hibernating creature is up to six months, and its heart rate drops significantly from around 400 to 25 beats in a minute. Their breathing slows, and at times they can also stop breathing entirely for an hour at a time.
These are some of the animals that hibernate for long terms and can sleep heavily for six months or more.
It is believed that Hummingbirds don’t sleep at all. But the reality is that Hummingbirds do sleep!
These birds are one of the animals that hibernate and enter into light hibernation, called torpor, during the colder temperatures and sleep to conserve energy. Their hibernation period is also variable.
When the cold temperature, these birds compel their heartbeats and metabolism to slow down to get through the harsh winters. They try to burn less and less energy as finding nectar, their prominent food, and insects in the subfreezing weather is brutal.
Hummingbirds need about half their body weight of sugar daily to survive. And thus, they resort to winter hibernation every year.
Hummingbirds are the only birds that can fly backward, and when they go into their dormant state of sleep, they hang upside down from the branches of their favorite trees. At times, you can mistake their hibernation as being dead, but the truth is, they are just sleeping hanging like that.
9. Deer Mice
Like so many other animals, deer mice do not get into long-term hibernation and hibernate in bouts and pieces to endure the harsh weather.
Generally known by the name Field Mice, Deer mice are animals hibernating in groups. They bundle up together from morning to late afternoon to stay warm.
They wake up as the sun falls and search for food. After food forage is done, they come back to their hibernation spot and bundle up again.
These mice make their nests and are always in a spot from where access to food and water is relatively easy. And before hibernation, they also make sure to store some food resources in close vicinity of their nests so that they won’t have to waste energy in foraging to faraway places for food next time.
The span for which these animals hibernate is variable. It solely depends on the weather and their food resources.
10. Wood Frogs
Wood frogs are one of the animals that hibernate to complete extremes. They get into deep and complete hibernation to the point that they stop breathing altogether.
These hibernating animals are not picky when it comes to choosing their hibernation stop. They can hibernate just about anywhere that can give them even an ounce of warmth. They bury themselves underground, or under logs, within leaf-covered places, and in burrows.
And they remain in the same place for the rest of the winter.
During hibernation, their body temperature drops to the point that the liquid inside of their body turns to ice and freezes out. Ice crystals also start forming on the top of their skin, and their heartbeat stops completely.
But they don’t die. They remain in that state until the early rays of spring come and de-freeze them. After that, their heart starts pumping again, and they start breathing too.
Wood frogs hibernate for almost three months. Up until the winters are at their extreme.
Wood Frogs Survival in Extreme Conditions and their Reanimation in Spring: Expert Views
“Wood frogs have remarkable adaptive mechanisms that allow them to survive under harsh conditions, especially during the freezing cold of winter.
What makes them unique among many species is their ability for freeze tolerance. As winter approaches, they undergo [a process called] cryopreservation, during which more than half of their body water turns into ice.[This] is possible because a significant amount of glucose is generated in their liver and transported to various cells in their body as winter approaches.
This glucose functions as a sort of antifreeze by reducing the freezing point of body fluid and preventing cell shrinkage.
In other words, wood frogs convert [themselves] into a frozen state, where their heart stops beating, their breathing ceases, and their blood freezes.
Even in this seemingly lifeless condition, they sustain the critical minimum cellular function by maintaining a balance of electrolytes and preventing cell death from lack of oxygen and build-up of harmful components.
In essence, the wood frog enters into a state of hibernation without metabolic activities, enduring the harsh cold of winter in a freeze-tolerant state.[This] is a perfect example of an extreme physiological adaptation in response to extreme environmental condition.
Once the spring arrives and temperatures [begin to] rise, the frozen frogs start thawing from the inside out.
The frozen glucose and other ions return to [their normal state], water starts flowing back into the cells, and metabolic activities resume almost instantly.
Their heart starts beating, and within a day or two, they are hopping around just like normal, as if they hadn’t just been in a state of suspended animation for months.
Understanding the physiological adaptations of the wood frogs opens up a wide range of insights into the survival strategies of organisms in extreme environments.
This knowledge is invaluable [not only] from a biological perspective, but for broader understanding of adaptation and survival under extreme conditions.”
It is predominantly inhabited by water and becomes very strenuous for land snails to survive in cold weather when all the water bodies crystallize due to low temperatures.
Extreme cold without moisture can prove to be lethal for the snails, forcing them to hibernate until some tolerable climate has arrived.
Snails are such animals that need moisture for surviving, and even through hibernation, they have to make sure that they have the proper resources. So, snails create a layer of water at the mouth of their shell with the help of their multi-purpose mucus. This keeps them hydrated through their hibernation.
They are not picky about their hibernation spot, and Snails hibernate by just withdrawing inside their shell and laying on the layer of water they have built comfortably.
Snails are the kind of animals hibernating in groups and can stay in hibernation for three years if the need comes to it.
Bears are one of the most renowned animals that hibernate. But like every other animal, not all species of bears hibernate. Only the ones that live in adverse weather conditions do.
For example, African bears that live in warmer places and can find food resources all year long see little to no reason to hibernate.
Bears choose to hibernate in precisely picked dens that are adequately insulated. And these dens could be built in hillsides, caves, crevices of giant rocks, or hollow trees. Bears tend to choose a dark and isolated place so that they can stay there undisturbed until the temperature warms.
Prior to their hibernation, Bears increase their food intake twofold towards the fall of summer. So, when they need to get into hibernation, they can enter into deep slumber without worrying about their energy resources.
They enter into a state of inertia and can stay in hibernation for about six months, from the winter to early spring.
13. Common Poorwills
Mainly found in western North America, Common poorwills are well known for their unique ability to stay dormant for long periods in winter.
These birds are insectivorous, and experience fluctuations in their food with the weather changes. And it proves to be extremely difficult for them to find insects during the colder temperatures.
So, to survive harsh weather conditions and lack of food, these birds enter a hibernation-like stage by reducing their body temperature and metabolism activities.
Common poorwills are the only known birds that truly hibernate. Like, for they can get into a deep slumber for one to three months. And unlike other birds-they do not enter into a state of light hibernation.
These animals hibernate in remote places like a patch of grass, a hollow branch of a tree, or any other isolated warm place they can find.
These birds use up their stored energy, accumulated in the warmer days, to survive through hibernation. And they can stay that way for long periods of time.
Looking a lot like Ground Squirrel, Chipmunks are primarily found in North America, where they prefer living alone in burrows or holes called dens.
These are some of the animals that hibernate in winter but don’t sleep for long times. During hibernation, the body temperature of chipmunks falls drastically, so they wake up every few days to bring their temperature back to normal and restore their food storage.
One other reason why Chipmunks don’t sleep for long is that, if they enter into the deep sleep stage of hibernation, their heart rate drops from about 350 to 4 beats a minute.
And their body temperature drops drastically from 94 degrees Fahrenheit to whatever the temperature of its den is-which can be as low as 40 degrees F-making it hard for them to wake up.
Chipmunks build their winter dens every year by digging an underground burrow. And before going into hibernation, they store their holes with as much food that can last them the entire winter.
These are some of the cold-blooded hibernating animals to survive through adverse weather conditions.
Since lizards are cold-blooded or ectothermic, they don’t have internal heating capabilities. That means they depend solely on their surroundings for their body temperatures, making it difficult to survive in colder weather and compelling them to go into hibernation.
Lizards build their homes under rocks, tree trunks, hollow trees, or wherever they can find a warmer place and stay in hibernation for about five months. These animals generally tend to hibernate alone and can go on little to no food during their time in hibernation.
And they stay in that condition, with no food resources, until the start of spring. After that, they come out and hunt small insects and spiders around the garden.
So, this is the list of 15 hibernating animals. Although hibernation is different for all these animals, the underlying reason is the same: to survive.
It doesn’t matter if it’s a fat-tailed lemur or a ground squirrel; they hibernate to endure the hardships of weather.
Guest Author: Saket Kumar