There's definitely not a scarcity of squirrels running on the roads, climbing up trees, or playing in your backyard during most of the year, but you may have noticed that you hardly see them when winter comes around. Which begs the question, where do they go?
What Is Hibernation?
Hibernation is a state of being dormant. The animal will conserve energy to survive the adverse weather condition or lack of food. Their heart rate, body temperature, and breathing rate will drop to conserve energy, and it can last a few days or months.
Hibernation vs. Winter Rest
Essentially, winter rest is a milder form of hibernation. Animals will carry on with their normal activities, but much more sparingly. Mostly their days will consist of sleeping and eating, sometimes sleeping for days at a time. Their heart rate will drop, but metabolism and body temperature will stay the same, meaning they can be as active as they are in warmer seasons if needed.
In hibernation, most of the animal's bodily functions that are otherwise essential shut down to preserve energy. They won't need to eat, drink, or have urinary or bowel movements for long periods of time. Amazingly, their bodies can resist muscle depletion and cell loss while hibernating. Contrary to popular belief, hibernation does not verbatim mean sleeping; however, their activity levels are much lower so they can survive the harsh winter.
Do Squirrels Hibernate?
In the animal kingdom, many types of animals will hibernate during wintertime. But do squirrels hibernate as well? The first thing to know is that there are different types of squirrels. Ground squirrels are the only species that hibernate, and tree squirrels adapt to a period of winter rest. Both events allow the squirrels to preserve their energy for strictly survival purposes, but there is a difference.
What Winter Looks Like for Squirrels
Squirrels instinctively know that it will be substantially more difficult to find supplies and food as winter approaches, so they start preparing in the weeks prior. It's commonly known that squirrels build nests year-round, and their winter nests are just thicker versions of their summer nests. They'll start to collect leaves, twigs, moss, and feathers to hunk up and insulate their nests for winter.
In addition, squirrels' coats have evolved to become thicker as the seasons change naturally. They also begin to eat more food to prepare for the cold season, keep their body temperature up when they need it, and forage more often so they'll have a stash of food for later, as most squirrels still eat in the winter, albeit less often. Squirrels will often be storing foods like nuts, acorns, and berries.
Some species like tree squirrel and the flying squirrel will share their nests come wintertime to keep each other warm and use less energy. Females will nest alone when pregnant.
Activity and Reduction
In the warmer months, squirrels will hoard their food in multiple locations near their nest, so if a predator comes along, their entire food source won't be gone, and they won't have to forage long distances while the weather is a threat to their livelihood.
Squirrels have impeccable memories and smelling abilities, which they use to their advantage when they're dormant. They spend the summer bulking up, so they'll have fat cells that burn slower once the weather conditions become inclement. They don't need to be as active but will have energy when it's necessary.
During warmer months, squirrels are active for around 12 hours a day. This dramatically shifts once winter comes around, and they will sleep for 18-20 hours per day, sometimes even for days at a time if the weather is especially harsh. Their sleep in the winter months is extremely deep, and if they are awakened forcefully somehow, it's difficult for them to get back to sleep and survive the abrasive weather conditions.
Where Squirrels Live In The Winter
In winter, squirrels tend to stay in their nests during colder months. In trees, burrows, or dens, depending on the species. Some squirrels make their homes out of holes that woodpeckers poke into trees.
You may find squirrels in your attic or garage, which is relatively unthreatening during the winter as they are mostly dormant, but if you find one in your house, that may be harmful as it can cause damage to the foundation of the building. To avoid this situation, cleaning your gutters before the winter is a good way to make sure squirrels stick to the tree rather than your home.
Squirrels also may migrate at times, traveling a few dozen miles, almost always because of damage like flooding. They only migrate to find new habitats, and seasonal migration doesn't occur because our everyday squirrels are just well adapted to modern buildings and streets.
All in all, there are hundreds of species of squirrels, and almost all of them participate in some form of hibernation. They prepare for this during warmer seasons by foraging for food and setting up multiple hiding places to keep it away from predators, building more on their nests for the best insulation, and gaining extra weight for warmth in winter. Most species of squirrels will invite others into their den to keep each other warm. Almost all squirrels go into a period of dormancy when the weather starts to get cold.
Where Do Squirrels Get Water During Winter?
Many assume squirrels drank a lot of water during preparation for winter. However, that is not the case, and it's the opposite. They drink less than usual as the animal's metabolism will remove electrolytes, sodium, urea, glucose, and other chemicals and store them elsewhere.
Non-hibernating squirrels will seek water sources from a non-frozen pond or heated pond. Some squirrels will even bring snow or ice pieces back home and wait until it melts to drink.
Winter is Different for Various Squirrel Species
There are more than 200 different species of squirrels, and they all behave differently come winter. They will all hibernate or go into winter rest, but their activity levels do vary considerably.
A ground squirrel looks very similar to a gray squirrel. One way to tell the difference is to look at the tails. Gray squirrels have a brushier tail to keep them balanced while running up and down the tree. On the other hand, ground squirrels have shorter and less bushy tails. Also, their fur is brown-gray with white-ish tails.
Unlike the other types of squirrels, ground squirrels are the only species of squirrels that truly hibernate, and this occurs for anywhere between five and eight months of the year. Most other species engage in winter rest and lay low while it's cold without going entirely into hibernation. And unlike the other squirrels that nest in trees, ground squirrels live on or in the ground.
Unlike ground squirrels, tree squirrels will locate their nest in deep tall trees' cavities and trucks to give them as much protection as possible from the environment.
Eastern Gray Squirrels
An Eastern gray squirrel is a type of tree squirrel, and it's pretty active during the day during winter and will not go into hibernation. You most likely will see them at bird feeders and scurrying around your yard.
Red squire is another type of tree squirrel, and both red squirrels and grey squirrels' winter prep and behavior are very similar. Unlike grey squirrels, red squirrels prefer to nest in thick evergreen trees between tree cavities for some protection.
Fox squirrels are mostly solitary squirrels, but they may nest together over the winter breeding season. And female fox squirrels will nest with their babies during the winter months.
One of the few types of squirrels that don't hibernate at all are flying squirrels. They will nest once it gets cold out, but they have a couple of spurts of energy throughout the night, and this pattern only ceases once temperatures get well into the negatives.