Do Flying Squirrels Hibernate? [Plus More Interesting Facts]

Have you ever met a flying squirrel? It’s not surprising if you haven’t because they are great at keeping themselves hidden. They’re also lightning-fast and operate mostly at night. But how do these critters keep warm when the days start getting shorter and the temperatures begin to dip? Do flying squirrels hibernate?

Flying squirrels are active throughout the year. They do not hibernate, but when food is scarce in winter, they form aggregations in tree cavities to conserve energy. They use nonshivering thermogenesis to regulate their body temperatures. They also fatten up and slow their metabolic rates down.

Nature is marvelous. When circumstances become unfavorable for animals, their bodies have built-in mechanisms to overcome them to ensure survival.

This is the case with flying squirrels in the wintertime too. Read on to find out how these creatures thumb their noses at winter and survive bitterly cold temperatures.

Do Flying Squirrels Hibernate In Winter?

Flying squirrels are active throughout the year, like their ground and tree cousins. But, while they don’t hibernate to survive the cold, they use other mechanisms to endure it.

Like nonshivering thermogenesis, bulking their bodies up, slowing their metabolic rates, and decreasing their activity. They also huddle together in communal nests.

Flying Squirrels Form Aggregations In Winter

Although they don’t hibernate, flying squirrels nest with other squirrels in old woodpecker holes, nesting boxes, snags, and abandoned nests of other squirrels or birds.

They will nest in groups of ten to twenty squirrels, sometimes even sharing with other animals, like screech owls and bats. They line the nests with twigs and grass and snuggle close to each other, sharing body heat.

In true squirrel tradition, flying squirrels build up food caches for winter.

They do this for two reasons. First, food is more scarce during winter. And in addition, if they have food stores in the nest, there is less need for them to venture out into the cold to find resources.

This is one of the primary ways they decrease their activity during winter.

Flying Squirrels Increase In Body Mass During Winter

While some mammals lose weight during winter to conserve energy, studies have shown that flying squirrels get bit plumper during the coldest months. The extra weight also helps them to stay warm.

What Do Flying Squirrels Eat?

These flying (or gliding) rodents are omnivorous. They will eat almost anything they can lay their hands on.

Their typical diet includes fungi, nuts, seeds, acorns, dormant insects, lichen, and wild cherry pits. During summer, they also feed on mushrooms, wild grapes, persimmons, and the bark of some hardwood trees.

Some flying squirrels supplement their diets with eggs, carrion, and birds.

Flying Squirrels Use Nonshivering Thermogenesis To Stay Warm

Flying squirrels stay warm by using Nonshivering thermogenesis (NST). It is a head-production system in mammals that plays a role in chemical thermoregulation.

NST can produce the same amount of heat in small mammals as shivering.

The hypothalamus regulates NST, and it occurs mainly in brown adipose tissue and skeletal muscles.

Studies have shown that NST is much higher in flying squirrels during December and January when the temperatures are at their lowest. NST is activated in the squirrel’s body when temperatures drop, and food becomes scarce.

Flying Squirrels Decrease Their Metabolic Rate In Winter

All living creatures need food to produce energy for their bodies to function. A lot of the energy stored in an animal’s fuel molecules is released in the form of heat.

Some animals, including flying squirrels, maintain a fairly consistent body temperature by regulating their metabolic heat production. Such animals are called endotherms.

Some animals react to seasonal cues by slowing their metabolic processes and decreasing body temperature.

This will induce a physiological state called torpor. It’s a state of reduced metabolism and activity that allows the animal to survive harsh conditions and conserve energy.

Torpor can continue for various lengths of time. However, for some animals, the shortening of the days and cold temperatures will be cues for animals to enter into hibernation.

Other animals enter a state of torpor during the summer months when the days are long and hot, and water is scarce. This type of torpor is called estivation.

Flying squirrels don’t fit into either of the above categories. They decrease the energy and food necessary during the coldest times of the day when they usually need to increase their metabolic heat and body temperatures. Their torpor only lasts for short periods.

But they emerge from their torpor frequently to eat, forage, or maintain themselves.

Where In The World Do You Find Flying Squirrels?

Various species of flying squirrels reside in Asia, Europe, and North America.

Although 90% of flying squirrel species are found in Asia, North America is home to three kinds: the northern flying squirrel, the southern flying squirrel, and Humboldt’s flying squirrel– classified as a separate species in 2017.

All three American flying squirrels are tiny, but some species grow much bigger in the rest of the world, with the Chinese red-and-white giant reaching more than three feet long.

The southern flying squirrel is abundant throughout the eastern part of the USA, from Maine down to Florida and west from Minnesota to Texas.

The northern flying squirrel is found mainly in the Northeast, down the west coast, Montana, and Idaho.

Humboldt’s flying squirrel resides in forested areas along the Pacific coast from Southern British Columbia to Southern California.

Flying squirrels are common in many parts of the country, but chances are that you will seldom encounter them because they are nocturnal and live in wooded areas.

The best time to look out for them would be autumn evenings when they start stocking up on their winter pantries.

Fun Facts About Flying Squirrels

If you’ve never encountered a flying squirrel, you may not know:

Flying squirrels don’t fly but glide with the aid of a furry membrane called a patagium.
By eight weeks old, young squirrels can execute lateral loops, 90-degree turns, and other gliding maneuvers.

Final Word

Flying squirrels are fascinating little critters. Although some seem so tiny and helpless, nature has blessed them with a few mechanisms to get through the cold winters without hibernating.

They decrease their activity and metabolism, put on some weight, and snuggle up with some buddies for a mutual housewarming (or body warming) party with the snacks they squirreled away in the fall.

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