In the winter, the temperatures plummet, the snow blankets the ground, the trees and bushes are stark and bare. What happens to animals in winter? What is their survival plan? Some people feel sorry for the animals who have to endure the elements but don’t worry. They have a plan.
Let’s take a look, and don’t forget to check out the free resources we have linked here to help you round out your study of animals in winter.
This unit covers migration, adaptation, hibernation, torpor, and much more. Includes science experiments (with common household products), activities (even a fun bat STEM activity), nature journaling pages, 3-part Montessori cards, and a mini-reader book that has all the informational reading needed to go with the unit. It’s truly all-inclusive!
Animals in Winter – What are the Different Ways Animals Survive?
Animals prepare for and survive through winter by adapting their bodies, behavior or both.
Hibernation and migration are two ways animals in winter adapt. Some animals do not migrate or hibernate but undergo physical and behavioral adaptations while remaining active in the same habitat.
For example, wolves grow a thicker coat of fur yet do not hibernate or move to a warmer geographic location. They tough it out!
In the fall, as the amount of sunlight during the day is reduced and hormonal signals happen, animals begin to experience changes in their body and behavior to prepare them for the coming winter.
(Note: Photoperiod is the amount of time there is sunlight during the day. Photoperiod changes also affect plants throughout the year. When the photoperiod or amount of sunlight increases or decreases, plants may respond by producing fruit, seeds, more chlorophyll, less chlorophyll, etc. Animals respond in their own ways to the photoperiod, most notably as fall and winter approach.)
Hibernators will begin to store up food, look for a place to settle in for the winter months, and some animals, such as bears, begin to eat more and store up brown fat.
Animals that migrate may begin to move to their new habitat.
Other animals will stay in the same area but will begin to gain weight, change colors, grow a thicker coat to adapt to the upcoming changes in temperature and food availability. This process is called adaptation.
Let’s look at each of these in more detail.
Animals in Winter – What is Hibernation?
Hibernation is when an animal’s heart rate slows to only a few beats a minute, their body temperature drops significantly, and their breathing rate is greatly reduced. During this time, the animal uses very little energy.
There are two types of hibernation we will discuss – true hibernation and torpor.
True hibernation is involuntary; this means it is triggered automatically by the animal’s body in response to the environment.
True hibernators typically have a body temperature that will go below 68 degrees Fahrenheit or 20 degrees Celsius.
Animals that are true hibernators will stay in this physical state for long periods of time (weeks or months) without eating or leaving their nest, den, or cave. Some animals may appear dead. True hibernators are more difficult to rouse; it can take several hours for them to be able to move around well enough to feed and defend themselves.
True hibernators do have periods of activity to find food, eliminate, or even give birth, but then they do go back into their state of inactivity. Their body temperature, heart rate, and metabolism will lower again.
True hibernators include chipmunks, prairie dogs (also known as woodchucks), some bats, turtles, snakes, reptiles, amphibians.
Chipmunks can reduce their heartbeat from 350 beats per minute to 4 beats per minute during hibernation. The body temperature of a groundhog drops from 98 degrees Fahrenheit to 40 degrees Fahrenheit!
What is Torpor?
Torpor is a lower-energy, lower-activity state some animals in winter experience. It is voluntary behavior.
Like hibernation, animals in torpor will experience a lower body temperature, heart rate, and breathing pattern. Their metabolism is also slower.
However, they come out of this low-energy state more often to feed and eliminate. When in torpor, animals are easier to rouse. Torpor can last a day, a few days, or a few weeks.
If you are in a geographic location that does experience a winter with cold enough temperatures, animals in winter in your yard or community most likely experience torpor. These include birds, raccoons, squirrels, skunks, mice, and honey bees.
Interesting Facts About Animals in Winter Hibernation
There are many fascinating facts about animals in winter hibernation. Here are just a few:
- Honeybees cluster together when they hibernate in their hive when the temperature gets below 57 to 59 degrees Fahrenheit. They surround the queen to keep her warm. They feed off the honey they produced. This process is called over-wintering.
- Some snakes may hibernate alone, but most hibernate in large groups. These groups can reach over 1,000.
- In zoology, the physical location where an animal chooses to hibernate is called hibernacula. This can be a cave, den, hollow of a tree. It’s the physical space where they seek shelter and protection. (In botany, hibernacula refers to the protective covering over a plant’s bud.)
- As cold weather approaches, brown bears will begin eating more in an effort to store up brown fat to help them survive through the winter. This time period of gaining fat is called hyperphagia, which means huge eating.
- Katmi National Park is famous for its bears and bear watching. Below in the section of resources are links where you can see photos of bears before hyperphagia (time of huge eating in preparation for winter) and after. Plus, there is a link to a live river cam. (During hibernation months, there are “reruns” playing. But during the rest of the year you can watch the bears live at the river feeding on salmon.)
Animals in Winter – Migration
Some animals do not stick around to feel the winter winds and brave the cold. They head south where the climate is warmer (whether they live on land or in the ocean) and the food is plenty.
Migration is the movement of animals from one geographic location to another where the temperatures are better, food is plentiful, and it’s a good location to give birth and begin raising their young. Some animals travel in large groups, like caribou or pronghorn. Other animals are solitary migrators, like ruby-throated hummingbirds.
Animals like hummingbirds, gray whales, monarch butterflies, some bats, and caribou migrate from colder to warmer climates as the winter months approach. Some animals migrate during other times of the year to find a new food supply or mate and give birth to their young.
For example, when animals on the Serengeti run short on tall grasses to eat, they must migrate to areas with a more plentiful food supply. These animals travel throughout the year on a circular route. This migration is called the Great Migration.
Migration can be a short distance of a few hundred miles or thousands of miles. Arctic terns travel the farthest of any migrating animal. They migrate from the North Pole to the South Pole and back again. This is a 25,000-mile round trip journey.
Pronghorns migrate about 200 miles from their summer lands in Montana to their winter home in Wyoming near Yellowstone National Park and the Grand Tetons.
Animals in Winter Migration – How Do Animals Know What Migration Route to Take?
Several triggers can affect when an animal begins to migrate for winter. These include:
- Internal body signals
- A change in daylight hours (less sunlight during the day)
- Temperatures getting cooler
- Food becoming more scarce
A migration route is the route animals take when they move (migrate) from one geographic area to another.
How do animals who migrate in winter know what route to take? It almost seems like there are invisible highways in the sky, overland, and in the ocean that birds, fish, and land animals instinctively know to take.
Scientists continue to study the migratory behaviors and routes of animals.
The routes scientists have identified for birds migrating in winter are called flyways. Three groups of flyways have been identified across the globe: the Americas Flyway, the African-Eurasian Flyway, and the East Asian Australasian Flyway.
There are four flyways in the Americas Flyway. Moving from the east coast to the west coast, these four flyways are the Atlantic Flyway, Mississippi Flyway, Central Flyway, and Pacific Flyway.
You can read more about the flyways at the end of this post in the resources section.
Scientists believe animals use different methods when taking a specific migration route:
- Internal instincts
- The magnetic field of the earth
- Following along a coastline, mountain range, river, or other physical features on the earth
- Following features on the ocean floor
- Using their sense of smell
- Following the sun or the stars
Animals in Winter – Adaptation
One of our favorite things to do after a snowfall is to take a walk in the fresh snow and look for animal tracks. The snow offers a blank slate to collect evidence of the movement of animals in winter.
We have already talked about three ways animals in winter adapt to the cold temperatures and difficult feeding situations – hibernation, torpor, and migration.
Other animals adapt by changing physically and toughing it out! Animals in winter that stay in their habitat and remain active include shrews, mink, voles, grey squirrels, foxes, and red squirrels.
In our area, we might see cottontail rabbit, deer, fox, coyote, or squirrel tracks. These animals do not hibernate or migrate. They are as active as ever in the cold winter months. They simply adapt.
Some ways animals adapt:
- Most mammals, like foxes and deer, grow thicker coats of fur during the winter months and/or increase their fat storage in order to be insulated from the cold.
- Birds puff out their feathers to trap air within the layers for insulation.
- Snowshoe hares, arctic foxes, and weasels grow thicker fur that is white (rather than brown). This keeps them warmer and well-camouflaged in snow.
- Many animals, like mice and flying squirrels, who are more solitary during the summer colonize in the winter months to huddle together for warmth.
- To maintain their body temperatures, animals must eat more than usual in the winter. Squirrels and Jays are known to hide away food in the fall to eat in the winter. Since food is scarce in the winter, this is very important.
- Animals like deer and rabbits do not store away their favorite foods. Instead, they change their eating habits to twigs, buds, and bark.
FREE Resource for Your Animals in Winter Study
We have created some Animal Report printables that can be used with multiple grades. Simply give us your email address so we know where to send it. You’ll be added to our email list, but we promise NOT to spam you. (We don’t appreciate spammy emails either!)
More Animals In Winter Resources
Want to learn more about how animals survive the winter?
Explore.org cam of bears in Katmai National Park in Alaska.Note that during hibernation months, they will replay highlights.
Brooks Camp is a world-famous spot for bear watching. The National Park Service has information on Brooks Camp and planning a trip.
Animals In Winter Craft
Get a free download and instructions to make this adorable Christmas animals craft.