Do Squirrels Hibernate? The Ultimate Reference

I have always wondered, do squirrels hibernate? Or not really? I have always assumed squirrels went into a deep sleep for the winter months, just like bears and many more wildlife animals. But recently, my curiosity was piqued about this topic; it seemed that no one could give me a straight answer about squirrel hibernation.

do squirrels hibernate - baby fox squirrel in den

Not until recently did I think much about what these little furry creatures did in the winter. Well, I suppose it is time I find out the answer to the question ‘do squirrels hibernate’ and share it with you.

What is Hibernation?

Animals hibernate to conserve energy by slowing their heart rate, lowering their body temperature, and breathing.

Hibernation includes long periods of inactivity and is vital to help them survive through wintertime when food sources are scarce or unavailable.

Do Squirrels Hibernate – Tree Squirrels

Tree squirrels are furry, tree-dwelling animals that are found all around the world. Tree squirrels come in over 100 different species and inhabit every continent except Antarctica and Oceania.

They do not hibernate during the winter because they cannot store enough energy to make it through the winter. However, they do sleep a lot!

do squirrels hibernate - baby fox squirrel in den
baby fox squirrel in a den

The squirrels alternate between long periods of sleep and coming out every several days to dig up the nuts they squirreled away before old man winter showed up.

Squirrels are crafty little critters you sometimes see carrying their food around. But they don’t just eat and run. They have a storage system that could rival the CIA for secrecy!

When food is more abundant in warmer months, squirrels will cache (hoard) their favorite foods like nuts and bury them. They hid them by digging small holes in the ground or sometimes using abandoned burrows (a tunnel or hole) or even flowerpots.

If They Don’t Hibernate, How Do They Stay Warm?

It is not uncommon to see squirrels scurrying around in the wintertime, but they prepare for the long and cold season far in advance. Before winter, squirrels begin changing their eating habits by consuming more food than usual to build an extra layer of fat insulation.

This behavior sounds oddly familiar during the winter for me as well! Oh, but back to the squirrels. The extra fat layer provides body warmth for harsh weather such as freezing spells, snowstorms, and blizzards.

To stay warm, the squirrels, who usually prefer to live alone, turn to sharing a nest and staying close for warmth. They also make use of shivering as a way to generate body heat in frigid temperatures.

Shivers are muscle contractions that produce heat when they occur at high rates due to cold environments.

Tree squirrels use holes, sometimes made by woodpeckers, in trees for shelter during the winter. This type of dwelling structure is called a den.

They will bring dried leaves, twigs, grass, and other materials, like padding, from your patio furniture cushions to build up layers of insulation inside the den.

If a squirrel can’t find a den, it will build a nest (sometimes called a drey) in a fork of a tree (where two limbs come together). Whether they choose to live in a den or a nest, both are vital to a squirrel’s survival during the cold.

If there is insufficient insulation, food stores, and fat insulation, these little critters can freeze!

Do Squirrels Hibernate – Ground Squirrels

Ground squirrels are one of the most well-known hibernating animals. Every few weeks throughout its hibernation cycle, a ground squirrel will warm up every few weeks by shaking and shivering for 12-15 hours to produce intense heat. They continue shaking and shivering until their body temperature is around 96.9 degrees Fahrenheit (36 degrees Celsius). This alternating pattern ensures the brain gets enough oxygen during long periods of sleep.

This pattern barely maintains life functions during hibernation, so they have enough energy to last through the long winters when food is scarce.

California Ground Squirrels

In some areas of California, where there is no snow, the ground squirrel will not hibernate but remain active year-round. These fantastic little creatures have a type of hibernation in the sweltering months called estivation or “summer sleep.

When ground squirrels face high temperatures and very little drinking water in the summertime, they will lie dormant in “summer sleep” to escape these conditions.

Do Squirrels Hibernate – Flying Squirrels

Flying squirrels are the most elusive of all North American mammals. Unlike tree and ground squirrels, flying squirrels come out at night and spend their days in their nest or den. They have excellent night vision that helps them gather food for winter to survive through cold winters.

Being active at night and spending most of their time in the trees rather than the ground helps keep them safe from predators like hawks, who can swoop down on them without warning.

Like tree squirrels, flying squirrels do not hibernate; instead, they gather in groups to stay warm from each other’s body heat. They slow down their metabolism and body temperature for energy conservation purposes but are not considered hibernation.

Did you Know That Flying Squirrels Can’t Fly?

Flying squirrels are not capable of actual flight; instead, they glide in the air from branch to branch. The patagium, a membrane that stretches between their front and hind legs, helps them glide.

Their tail is the steering wheel that guides them through the forest like an airplane on autopilot.

Final Thoughts on Do Squirrels Hibernate?

Now you have your answer to the question, “Do Squirrels Hibernate.” Squirrels are unique and resourceful little critters. If you see squirrels out and about on a cold, snowy winter day, you know they have just awakened from a long nap to grab a snack. If you are interested in more fun facts about squirrels, this article is worth checking out!

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  1. ?? I knew that Fox Squirrels don’t hibernate, ? ❄ as I watched the Fox Squirrels here in Texas live through the #snowmageddon2021
    All safely accounted for after the snow melted. But it was interesting to learn that some other types of Squirrels do hibernate. Great article ?

    1. @Karon_kritters taught me about tree squirrels and hibernation a couple of years ago. Now I am learning so many more things as I write for the website about squirrels. There is so much to learn, but I wish there was more documented research to reference.

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