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Do Squirrels Hibernate? 3 Things You Didn’t Know

Hibernation is a familiar condition among animals such as snakes, bats, woodchucks, hedgehogs, bears, and turtles during winter. But do squirrels hibernate being that they are mammals?

It is rare to find a squirrel moving around outdoors in the winter period, and the only thing to think of is that they are hibernating, but how true is that?

If you love squirrels then stay with me and learn what happens to these fascinating creatures in wintertime. Don’t leave the site as there is a lot to learn.

Do Squirrels Hibernate?

squirrels don't hibernate
squirrels don’t hibernate

Typically, squirrels don’t hibernate, but some species, like the ground squirrels, will always fall into a deep sleep to escape the extreme cold in winter, and by this, we say they are hibernating.

Although tree or flying squirrels usually don’t hibernate, they have a unique way to prepare themselves for cold winter months. They can detect when the winter is approaching with the help of their internal photo-neuroendocrine system.

The system helps the squirrels feel the day’s length changing and know it’s time to begin prepping. The different ways squirrels prepare before wintertime are putting on considerable weight and filling their hoard with nuts, bones, seeds, insects, and berries.

During winter, the squirrel can access these foods with ease and sustain them until the period is over. These animals have different nests and tend to choose the warmer ones and reside in during the wintertime.

The squirrels distribute the foods in all these nests, a practice called scatter-hoarding, but they can also scatter the food in secured places at a distance from the nests.

The good thing about scatter-hoarding is that it minimizes theft. If food from one area is stolen, the squirrels can depend on food from other different locations.

Why Do Ground Squirrels Hibernate During Winter but Not Tree Squirrels?

Similarly to people, tree squirrels spend most of their time inside during wintertime, and the nests are warm enough to provide the necessary warmth. The same case applies to the flying squirrel, which is also active all year-round. Also, these squirrels are unable to retain sufficient body fat to survive.

Warm nests help these squirrels to survive the cold weather, and they also depend on the fat reserves and food in hoards for the same purpose. They come out of the drey on certain days, and you can see them moving around in your yard or garden, but they usually visit the areas that they know there is food waiting for them.

On the other hand, ground squirrels such as large yellow-bellied-marmots, Richardson’s ground squirrel, and others tend to hibernate for more than seven months. But what makes the ground squirrels hibernate and not the tree squirrels?

The body temperature, heart rate, and body metabolism of ground squirrels fall dramatically in cold conditions, and this makes hibernation the best way to avoid the extreme cold.

You may be wondering how such squirrels survive for such a long time, even without water. However, the truth is that they don’t feel thirsty, and probably this may apply to other hibernating animals.

This is made possible by regulating blood concentration. Squirrels remove electrolytes such as sodium, urea, and glucose and store them at a specific place in the body, such as in the bladder. With low blood concentration, there is no thirstiness.

Do Tree Squirrels Sleep During Winter?

Yes, tree squirrels sleep most of their time in the nest during wintertime instead of hibernating. They tend to be active for a few hours, early in the morning and late in the evening.

In the day’s main body, these squirrels are sleeping and can sleep even up to 20 hours in a day. So, when you don’t see squirrels in cold seasons, they are merely sleeping.

During the warmer months, be ready to see squirrels’ movements as this is when they forage and collect and store seeds and nuts and other different foods.

It is not unheard of that a squirrel can hoard up food that can sustain them for three years, and this is pretty common with the grey squirrel.

They can locate the hoarded food during winter through the aid of their sense of smell, plus distant and local landmarks. Winter is associated with scarce food and water, but we can be sure that this does not affect squirrels due to their accurate planning.

Winter can get severe and will force a couple of squirrels to inhabit one nest for additional warmth. But in standard cases, one nest is meant for one squirrel unless the mother squirrel has babies.

What Do Squirrels Do Before Hibernating?

By now, you are aware that squirrels take notice of the changing seasons through photo-neuroendocrine system aid. This is a sensitive collection of hormones, neurons, and glands that adjust the internal chemistry about the length of days.

The squirrels perceive when day-length begins to shorten in the fall, and they start to prepare for the winter. The following are various activities squirrels engage in before the winter months and before getting into hibernation.

Nest Building

Squirrels indeed live in the nests year-round, but a special drey or cavity den is essential to facilitate warmth and allow the squirrels to stay well during winter. They make the nests from leaves, twigs, or moss in tall plants.

The holes left on hardwood trees by animals such as woodpeckers become the cavity dens where squirrels reside. The squirrels can build multiple nests or cavity dens to choose the one that offers the best warmth and help them evade their attackers.

Even though the squirrel is deep asleep when hibernating, a fancy nest is essential to make it stay nice. So, both the hibernating and tree squirrels build nests as winter approaches.

Scatter Hoarding

As stated earlier, scatter hoarding has to do with squirrels storing foods in different places for the winter. Squirrels scatter food around nests or off the territory and come during the day in the winter to eat.

These animals have a unique spatial chunking technique, which helps them remember where they hide their food. A squirrel is a smart creature and will pretend to bury food in a particular location but eventually bury it somewhere else to keep off thieves. All similar foods are buried in similar places, and the squirrels can remember these locations.

Building Up Fat Reserves

Squirrels bury food in the underground when getting ready for winter and store fat on their bodies to keep warm in low temperatures. The fat also provides the energy a squirrel requires for survival, especially when there is food scarcity.

Lowering the Serum Concentration

High serum concentration brings thirst and can make the squirrels wake up from hibernation and look for water. But since this does not happen, the squirrel has to remove electrolytes like sodium and store them, for instance, in the bladder, to lower the serum concentration.

That explains why squirrels under hibernation stay even for about eight months without drinking water.

Where Do Squirrels Sleep at Night in the Winter?

Where Do Squirrels Sleep At Night In The Winter?
Where Do Squirrels Sleep At Night In The Winter?

Nests or cavity dens are the typical homes for the flying and tree squirrels, while ground squirrels, as the name suggests live under the ground, in holes. These are the same habitats squirrels live in even during wintertime; no other special place is provided.

As I mentioned before, squirrels get up pretty early in the morning and late in the evening. The squirrels are sleeping in their nests they built or found in trees and hibernating squirrels stay on the ground the whole night and during the daytime.

One nest can accommodate several squirrels when the cold gets extreme in the winter season, but squirrels stay alone if it is not too cold. Males rarely inhabit one habitat, but a couple of females will freely share a nest.

While tree squirrels usually live alone except under some circumstances, as we have seen, ground squirrels often stay in groups.

At daytime, squirrels run up and down in the yards and up trees. Such an exercise helps to burn up energy. Then at night, they need to rest and catch up some profound sleep for their well-being. So, if you encounter a squirrel’s habitat, it is healthy to respect it rather than destroying their sleeping place.

Do Squirrels Eat During Hibernation?

Do Squirrels Eat During Hibernation?
Do Squirrels Eat During Hibernation?

Tree squirrels are active even during the cold months, and they go out of the nest to collect food they have buried and perform some maintenance in the habitat. However, ground squirrels are inactive and hibernate in their holes.

During winter, the ground squirrels rarely leave their habitats. But they infrequently need to leave their homes in the ground and get a place to urinate. This may happen because the internal bodily processes do not entirely stop like in animals like bears.

Apart from urinating, the squirrels may need to eat some food occasionally. Hence, although a squirrel is hibernating, it will need food, but this happens less often.

The underground shelter may contain various tunnels where some are sleeping places, and the others house the food.

How Long Does Squirrels Hibernation Take?

Generally, squirrels can hibernate for around 5-8 months, depending on the species. For instance, Belding’s ground squirrels stay under hibernation for a long time, and they emerge in the late spring.

Therefore, before the winter, these squirrels forage on green vegetation and fatten up to prepare for the long hibernation ahead. They hibernate in and around late July. While females hibernate in groups, males stay alone.

Hibernation can go up to 5-7 months, and males are usually the first to wake up from deep sleep, while females emerge about two weeks later.

Another species is the California ground squirrel, which also hibernates during winter and tends to emerge from the burrows at the end of January. Still, some will wait until March. Likewise, males emerge first, and females follow about ten days later.

That is a long period for animals to hibernate, but they have a brief arousal period when they awake for a bit before getting back into a virtual coma.

What Do Squirrels Do After Hibernation?

What Do Squirrels Do After Hibernation?

Understanding hibernation duration for different squirrel species is essential to help you know when breeding will occur. Typically, when squirrels emerge from hibernating, the next process that follows is mating.

California ground squirrels emerge from hibernation as early as the end of January, or they can wait until March. After hibernation, mating can begin as early as January in warmer areas, and this proceeds until July.

There is peak mating from March and through June. When we look at the Belding’s ground squirrel, the mating period takes place from late May until early June. These squirrels produce one litter in a year containing 3-8 youngsters.

During reproduction, young female squirrels tend to produce a large litter. The mothers nurse their offspring until they are entirely independent, where they move out and build their own homes.

Since there is no eating during hibernation or squirrels eat occasionally, you will realize your squirrel has lost a fair bit of weight. Therefore, there is a need for the squirrel to eat well to help regain weight.

Squirrels mating
Squirrels mating

Wrapping Up

If you were wondering whether squirrels hibernate or not, the answer is yes. Squirrels hibernate, but it depends on the species. The only species known to hibernate are the ground squirrels, such as the California ground squirrels and others.

On the other hand, other species, including the flying and tree squirrels, do not hibernate but remain relatively active during winter. They prepare this period by hoarding abundant food, building body fat reserves, and building lovely nests or cavity dens.

The hibernating squirrels may emerge in certain moments to urinate, and some of them need to eat occasionally. Ground squirrels are experts in burrowing, and they make several tunnels in the burrows for sleeping and storing food. They stay in these holes even during winter.

Squirrels can hibernate for around five to seven months, and we have seen that males are always the first to emerge from hibernation, and females follow a few days later. I hope this article has been insightful and you found it interesting.

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