In areas with colder seasons, you can typically find animals that hibernate in the winter to survive the temperature drops. Hibernation is a state similar to sleep when animals conserve their energy through bodily transformations such as slowing down their heart or metabolic rates. Some species go into a deep “sleep” for many months, while others only go into a light “sleep.”
This article will provide information on animals that hibernate in the winter and how long they typically hide away.
15 Animals That Hibernate in The Winter
Here are 15 animals that hibernate. While you might know some on this list, others may surprise you to know they hide away during the winter.
1. Little Brown Bats
- Scientific name: Myotis lucifugus
- Hibernation period: 5 to 6 months
While some bat species migrate to warmer places during the winter, the Little Brown bat will tough out the cold by hibernating in caves or mines with high humidity. You can typically find them throughout the U.S. and Canada, including in Alaska. They typically enter hibernation in October or November and end in March, April, or May.
These bats will hang alone or in small clusters. They survive the winter by:
- Using 98% less energy
- Relying on their fat stores
- Reducing their heart rates from 200 to 300 beats per minute to 20 beats per minute
2. Eastern Chipmunks
- Scientific name: Tamias striatus
- Hibernation period: 4 months
You can find the Eastern chipmunk in wooded areas and parks in eastern North America. Including their tail, these animals grow to about 12 inches in length and weigh around 2.3 to 5.3 ounces.
Although these animals go into a deep sleep for hibernation during the winter, they don’t remain this way throughout the four months. Every few days, they will wake up to eat their stored food, urinate, and defecate before hibernating again.
3. Groundhogs
- Scientific name: Marmota monax
- Hibernation period: up to 5 months
Groundhogs, also known as Woodchucks, live only in the wild of North America and are known for their extensive tunneling systems. Their burrows can range from 8 to 66 feet long, with multiple chambers and exits.
These animals typically hibernate in their burrows from October or November to February or March. During this period, they reduce their body temperatures significantly, dropping below 68 degrees Fahrenheit.
4. Hedgehogs
- Scientific name: Erinaceus europaeus
- Hibernation period: 5 months
Hedgehogs, like the European hedgehog, are spiny animals that are around 7.8 to 9.8 inches long. They will typically hibernate from November to April. The exact start of their hibernation is triggered by multiple cold days that are around 41 degrees Fahrenheit.
These animals need to make sure they weigh at least 1.3 pounds before hibernation since they rely on stored fat to survive. During hibernation, their:
- Metabolism slows
- Body temperature drops from 95 to 50 degrees Fahrenheit
- Breath is one intake every 2 minutes
- heartbeat slows from 190 to around 20 beats per minute
5. Common Poorwill
- Scientific name: Phalaenoptilus nuttallii
- Hibernation period: 1 to 3 months
Unlike other birds that migrate, the Common poorwill is one of the first known bird species that hibernate during the winter. Since the insects they typically eat are scarce during the winter, these birds will find a place under a rock or log to begin their hibernation of up to 100 days.
Although scientists didn’t discover their hibernating habits until the 1940s, the Hopi people in America seem to have known long before that. The Hopi name for the Common poorwill translates to “the sleeping one.”
6. Striped Skunks
- Scientific name: Mephitis mephitis
- Hibernation period: 4 to 5 months
The Striped skunk is one of the more common types of skunks in North America and has the identifiable coloring of a black body with two white stripes along their backs. While these animals don’t enter into deep hibernation, they do slow down and enter a state of “sleep” known as torpor. Similar to hibernation, the skunk’s metabolism rate and temperature will reduce as they hide away in their dens.
They are known to block the entrance of their dens with grass and leaves to keep out any cold air. However, during this winter denning period, they may wake up and venture out at night to search for food if they feel hungry.
7. Fat-Tailed Dwarf Lemur
- Scientific name: Cheirogaleus medius
- Hibernation period: up to 7 months
Fat-Tailed Dwarf lemurs are primates and one of the only species that can hibernate for more than 24 hours. They will prepare for hibernation during the wet season by eating a lot of food to accumulate body fat in their tails. These animals have tails that can reach up to 40% of their body weight!
Although they can hibernate for up to 7 months, they will also periodically wake up every 6 to 12 days. During their “sleep,” their body temperature, metabolism, and heart rates severely decrease.
8. Yellow-Bellied Marmot
- Scientific name: Marmota flaviventris
- Hibernation period: 5 to 6 months
The Yellow-bellied Marmot is a stout ground squirrel that can grow 2 feet in length. They are burrowing rodents found in western U.S. states, with burrows up to 16 to 22 feet deep. These animals are known to hibernate in social groups from September to May. The exact time of their hibernation will depend on the elevation they live at and temperatures outside.
9. American Black Bears
- Scientific name: Ursus americanus
- Hibernation period: 3 to 5 months
American black bears will eat up to 20,000 calories a day during the spring and summer to prepare for hibernation. Their diet includes honey, insects, grasses, acorns, berries, birdseed, and even garbage. The males will typically retreat to their winter dens and hibernate from mid-December to mid-March. However, females will stay in the dens for longer, from November to mid-April, since they also give birth during the winter.
These animals are not considered true hibernators that go into a deep “sleep”; instead, they enter the state of torpor. Although their body temperature drops and metabolism slows, they are in a lighter “sleep” and can wake up after sensing intruders.
Check out this article for black bear population estimates in each U.S. state.
10. Prairie Dogs
- Scientific name: Cynomys parvidens
- Hibernation period: 6 months
Prairie dogs are social animals and a ground squirrel species growing around 14 to 17 inches long. They are tan or reddish-brown with whitish bellies and white hair covering the tips of their tails. As their name suggests, you can only find them in Utah, making them the prairie dog species with the smallest range.
These animals hibernate from November to February or March each year in their underground burrows. The exact time they emerge from hibernation will depend on the elevation they are at. Typically, males will emerge a couple of weeks before females.
11. Box Turtles
- Scientific name: Terrapene
- Hibernation period: 3 to 4 months
Although the process of hibernation for cold-blooded animals is technically called brumation, the specifics are similar where the animal goes into a sleep-like state and doesn’t eat or drink. Box turtles will typically hibernate from mid-September for three to four months. These animals don’t need to find a suitable location as they can simply withdraw inside their shell to hibernate.
12. Hazel Dormouse
- Scientific name: Muscardinus avellanarius
- Hibernation period: up to 7 months
The Hazel dormouse will eat in excess during the autumn months to gather stored fat in preparation for their winter hibernation. Although they mostly live in trees, they move down to the ground to hibernate.
These small animals grow around 2.3 to 3.5 inches in body length and have the same length for their tail. They will curl up in a ball during hibernation, wrapping their tail around their face to keep warm.
13. American Bullfrog
- Scientific name: Rana catesbeiana
- Hibernation period: 4 months
The American bullfrog can be found throughout eastern, southern, and parts of western U.S. In regions that have low winter temperatures, they are known to hibernate underwater. They require oxygen-rich water to survive the winter months and will lay on top of the mud or partially buried. Some will even slowly move during their hibernation period.
14. Roman Snails
- Scientific name: Helix pomatia
- Hibernation period: 5 to 6 months
While some snails die in the autumn after they lay their eggs, the Roman snail is a species with a highly developed hibernation ability. These snails can withdraw into their shell and close their shell with a lid to protect them from winter frosts. They tend to dig a hole in the ground to allow them to stay in this position through the winter, typically from October to late April.
This snail reduces its activity to only the most vital needs during hibernation, including reducing its heartbeat to a minimum. Some Roman snails are known to endure temperatures below negative 40 degrees Fahrenheit without freezing.
15. American Bumblebees
- Scientific name: Bombus pennsylvanicus
- Hibernation period: 6 to 7 months
Most American bumblebees will die during the winter. However, new or young queen bumblebees will stay alive and hibernate in burrows underground. During the spring, the queens wake up and lay eggs for worker bees, new queens, and male bees to recreate the hive. Once winter approaches, the old queens, worker bees, and male bees die, repeating the cycle.
Patricia is a wildlife enthusiast that loves traveling and learning about wildlife all over North America and the world. Aside from being writer for Wildlife Informer, she’s an avid bird watcher as well as the owner of several pet reptiles. She enjoys visiting national parks and seeing new sights in her free time.