Seasonal changes come with challenges for different animals. Some cope by adapting, others by migrating, while several go into a dormant state called hibernation.
That said, when speaking of hibernation, bears are the usual animal that comes to mind. They sleep and hibernate for several months until the winter passes and spring arrives.
However, did you know that smaller animals, like chipmunks, also go dormant in the winter? Although there’s a slight confusion about whether to call it hibernation or something else.
In this post, we’ll clarify the question of whether does a chipmunk hibernates or not. So stick with us, and let’s discuss how these adorable animals brave the winter and more.
Chipmunks are members of the squirrel family. However, they’re smaller than their bushy-tailed cousins, about four to seven inches in height and one to five ounces in weight.
Despite their small size, these striped furballs are more than capable of facing winter. It makes you wonder how these animals survive the freezing temperatures and hungry predators.
Well, it turns out that chipmunks do hibernate. But their way of hibernation is different from those of other animals, such as bears, groundhogs, and hedgehogs.
Instead of transitioning into a deep sleep that lasts for a few months like other hibernating creatures, chipmunks go into a lighter version of hibernation called torpor.
To understand the difference between these two processes, let’s compare how bears and squirrels behave before and during torpor and hibernation.
As you may already know, some bears eat non-stop to put on weight for several months before winter. We call this step of the bears’ hibernation process hyperphagia.
When bears hibernate, they go into a state of physiological dormancy, which slows down their organs and metabolism. They become inactive, saving energy until winter passes.
Most animals that hibernate do this voluntarily. And bears will remain in this state for two to seven months, depending on their location—species in colder regions hibernate longer.
Torpor in chipmunks, on the other hand, functions similarly to hibernation but without an extended period of physical dormancy. So, they’re not entirely inactive throughout the winter.
Like bears, chipmunks fatten up before the temperature drops. They’ll also stockpile food, gathering nuts and seeds and storing them inside their dens before falling into torpor.
However, unlike hibernation, this condition isn’t a conscious choice for these animals. You can think of torpor in chipmunks as an involuntary sleeping response to the cold temperature.
Unlike bears and other hibernating animals, chipmunks won’t remain asleep throughout the cold months. They’ll wake every few days to eat and move around.
For this reason, biologists and experts don’t consider this phenomenon true hibernation. However, it does have similar characteristics, like lowered metabolic rates and organ functions.
Chipmunks prepare for winter by preparing their den and collecting food. They’ll begin gathering in late summer in September and through fall in November.
Squirrels, particularly chipmunks, are known for their ability to forage food in large quantities. And one chipmunk can gather over 165 acorns in a single day’s work alone.
These adorable animals use their expandable cheek pouches when transporting food. They’d fill their cheeks with seeds, nuts, twigs, and other edible materials, all at once.
In a matter of days, a chipmunk can collect enough food supply to last for the entire winter. For this reason, chipmunks are known hoarders taking up more food than they need.
They store the food they foraged in their dens or stash it near their burrows. This way, they don’t have to go out and risk being spotted by predators throughout the cold months.
Once they’re satisfied with their food supply, the chipmunks will retreat into their dens. They usually do this beginning in late October or early November, depending on the temperature.
Like most hibernating animals, chipmunks torpor between late October and the middle of March. This period is commonly when the weather is intense, and the temperature’s too low.
That said, the duration of their hibernation depends on their location. Similar to bears, chipmunks living in colder areas tend to sleep longer than those living in warmer climates.
For example, chipmunks in the southern parts of the US live in warmer weather. For this reason, they will have shorter dormant periods from December to late January.
On the other hand, chipmunks living near the northern areas will hibernate longer. Experts found they can sleep for several months, much like a true hibernation.
As mentioned earlier, chipmunks don’t remain dormant for the rest of the winter. They’ll frequently wake from their torpor once every few days to replenish their energy.
While awake, chipmunks eat, excrete wastes, and warm their bodies. So you’ll probably see one or two of these furry creatures on a warm December day.
However, this brief active period doesn’t mean they’re done with their hibernation. After eating and prepping, chipmunks will return to their nest and sleep again.
This cycle will continue until the end of winter, usually around mid-March. However, in cases when the winter period extends, chipmunks will also prolong their torpor.
Where Do Chipmunks Hibernate?
Chipmunks hibernate underground in burrows and nests. They make networks of tunnels and complicated structures with their nests at the center.
Their den can span wide and can reach up to 30 ft long and 3 ft deep. Chipmunks also create rooms and crevices as food storage, bathroom, and nursery, where they’ll give birth.
Before their torpor, these furball architects will insulate their homes. They’ll fill their nests with insulating materials such as leaves, grass, and other soft materials for comfort.
Chipmunks will make a drainage system underneath the burrow to prevent rainwater from flooding their homes. It’s an excellent method so they don’t freeze in the winter.
They’ll start hibernating when temperatures begin to plummet. They’ll spend most of their time inside their nests, sleeping and eating until the weather starts warming again.
Chipmunks like to make their burrows near or underneath shady areas. This tendency is why you’ll usually find them under trees or structures, such as porches and decks.
The entrance to their lair is typically two to three inches in diameter. These holes lie flat on the ground, unlike moles or ants that create mounds of dirt in the surrounding area.
Most dens will have “plunge holes” as an entrance. It means the first foot or two will go straight down, leading to a long tunnel connecting with the rest of the structure.
There’s no limit to the number of entrances for a chipmunk den. Broader and older nests usually have more than one entry hole scattered around different areas.
These furry creatures make two types of holes. Aside from their den, they also make shallow burrows as temporary shelters while they forage for food during the day.
Similar to every other animal, chipmunks hibernate to survive the harsh weather. These mechanisms ensure they conserve energy when food is scarce.
When these animals enter this state, their heartbeat drops to four beats per minute. It’s a massive difference from their normal 350-per-minute heartbeat under normal conditions.
The incredibly slow organ functions are their body’s energy-saving mode. It maintains their body temperature and allows them to use stored energy much slower than in spring or summer.
Moreover, chipmunks hibernate for safety. On top of the weather, they also have to hide from hungry predators active in winter, such as hawks, weasels, and cats.
These predators are particularly active in the winter as they don’t go dormant. It’s why it’s safer for chipmunks to gather and store food rather than forage in the snow.
Chipmunks aren’t the only creatures in the animal kingdom that undergo torpor. Some varieties of bears, raccoons, bats, and skunks go into this temporary hibernation during winter.
In addition, several species of birds also go into brief hibernation phases throughout the day. One notable example of this process is hummingbirds going into torpor to survive cold nights.
Wildlife adapts differently to winter and harsh weather. And terrestrial creatures like chipmunks brave the freezing conditions by burrowing underground and through torpor.
These furry animals need to hibernate to escape predators and the cold. So, if you ever find a slumbering chipmunk smack in the middle of winter, it’s best to let the creature rest!
Ben has a bachelor’s degree in construction engineering. When not constructing or remodeling X-Ray Rooms, Cardiovascular Labs, and Pharmacies, you can find him at home with wife and two daughters. Outside of family, He loves grilling and barbequing on his Big Green Egg and Blackstone Griddle, as well as working on projects around the house.
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