Animal Adaptation: Winter
As the temperature drops, I find myself wondering how the animals in my yard cope with the cold. I have heard children ask questions that suggest that they too are concerned about how animals live and survive winter. How do birds keep their little feet warm? Do they have enough feathers to keep from freezing? Do rabbits hop because their feet get cold on the snow?
I live in the desert so temperatures rarely dip below freezing at night and during the day we are really quite fortunate to have lots of sunshine and relatively warm weather compared with other parts of the country. But I still wonder how the desert dwelling animals (such as bobcats, coyotes, javelina, and the iconic roadrunners), that I am fortunate to see and hear regularly, keep themselves and their little ones warm and fed during the winter months. What do they have to do differently to survive?
This idea of altering behaviors or one’s physical characteristics to survive cold temperatures, or extreme heat during the summer, is referred to in biology as adaptation. In its broadest sense, adaptation refers to the adjustment or changes in behavior, physiology, or physical characteristics of an organism so that it can better survive in its environment. The theory of evolution by natural selection informs us that these changes, if successful, are then passed on to subsequent generations so that they too can survive and thrive. Those animals that survive by successfully adapting can live on to have offspring. Those that don’t – can’t.
Is your child likewise interested or concerned about animal survival in freezing temperatures and how they might adapt? Perhaps keep things focused for the time being and think about animals in winter. More will be said about adaptation in later posts.
If you are not already familiar with this blog, please read the “What is Guiding Curiosity”
One more note: This activity is about animals in winter. I believe that it may be most useful to focus on adaptation among animals that your child can actually see and touch, or pets and animals in your neighborhood. I, like others writing on this topic for children, have included references to Arctic animals like polar bears and arctic foxes. I think these animals are certainly well adapted to cold, even frigid weather, but I wonder if the lesson may not be more meaningful to a young child if the discussion focuses on his more immediate environment. Just a thought that the distinction between the Arctic versus local environment is worth bearing in mind.
Every good discussion begins with a question that prompts investigation.
What do animals do to survive freezing temperatures?
How do animals get around on snow or ice?
How do they keep warm?
Do some animals become less active and even sleep all winter?
Where do animals live during the winter?
What can they eat if plants are dormant and other animals that they prey on may be less likely to be out and about?
Do certain animals change their coats or other parts of their bodies to help survive?
Do animals change their behaviors when it is cold outside?
Ask your child to consider what would help him to live outside during winter? What changes to his body or what behaviors would be necessary to survive? We humans have already adapted by building ourselves warm shelters and developing warm clothing to protect us from the elements, but what if we hadn’t figured out how to do that? How might we survive if we had to exist outside as other animals do?
If your child mentions an animal’s coat or fur, ask what might change (thickness, color, patterns). If she is thinking about paws (or feet), what might change for winter or help to walk on snow and ice? Eyes, ears, sleep patterns, or diet are also good topics to steer your child’s attention to in thinking about adaptation. How might these be affected by colder temperatures or less sunlight?
Another good place to start is just to establish how a habitat might change during winter (not just colder, but darker, less protective foliage for cover, the ground is hard and can not be burrowed into, fewer plants to consume). Once these changes have been established, then invite your child to consider how animals must adapt to these changes.
Often the best way to know or understand something is to look carefully or use other senses when appropriate.
I know it might be cold outside, but take a quick walk and look for animals in your neighborhood. Alternatively, find a window with a view of the yard and set up a lookout for observing animals. Draw a map of part of your yard and note the number or type of animals that can be seen in a given period of time.
Are there more or fewer animals as compared to in the fall or spring? What are they doing or how are they acting? Does their behavior seem different from what you remember from summer? That is, are they as active, do they sing as much? Do their coats or feathers look different in terms of color or thickness? Are they eating different foods?
Look for animal tracks in the snow. What animals are still active in your neighborhood during the winter months? Tracks may be distinguishable in the mud or dirt, but the best time to look is after a snowfall. Sketch or take pictures of those tracks.
Look for signs of animals eating during the winter months. Do you see mounds of acorns or trees missing bark?
Listen for animal noises. What do you hear? When do you hear it during the day? In the morning? How about mid-day when the sun is brightest?
If you have a pet dog, invite your child to feel its coat. Has the dog adapted to winter? With the exception of a few breeds, when the days grow shorter and temperatures cooler, dogs tend to shed their summer coats and develop thicker winter coats. Some grow an undercoat or their own version of long underwear. Does your dog’s coat change for winter? Also, dogs can fluff up their coats for additional insulation. Have you seen this happen? Do you have to comb out a lot of extra fur in the spring or summer? What was this extra fur?
If you are lucky enough to have access to other animals, particularly animals that can be touched, suggest that your child makes a determination by touching their coats whether or not they seem to have added layers to protect against the cold.
Drawing or sketching animals observed, or some part of their bodies or their environment always enhances observation skills.
Compare and Contrast
Young children love to classify things, and comparisons is an important way of knowing things.
Parents, once again you can help this process by finding photographs or images of animals or insects that adapt to winter months. There are a variety of mammals, such as snowshoe hares, whose coats change color as winter approaches, helping to camouflage them. Here are some other good examples: https://www.thedodo.com/7-animals-turn-white-winter-817375728.html.
For a really huge selection of photos check this out: http://www.weather.com/science/nature/news/animals-playing-snow-photos
White fur or feathers act as camouflage for animals and protects them from predators (or in the case of the arctic fox, it protects them from predators but it also means that their prey can not see them coming).
But how does white fur or white feathers help keep the animal warm? After all, black or dark colors absorbs heat and white reflects it. It turns out that white fur and feathers are still well adapted to cold climates. White fur and feathers lack pigmentation or color. The areas where that pigment would be in a cell can then be filled with air. That air can trap warmth and serve as thermal insulation!
Some animals remain white all year, like the polar bear. The white fur during winter allows them to creep up on their prey. The white fur also helps with flotation. Underneath their white fur, a polar bear also has a layer of black fur that absorbs heat from the sun. Lots of fat also provides insulation from the cold.
Other animals’ coats may lengthen or thicken for winter. See if you can find images of animals with thick winter coats as compared to their summer coats (horses, dogs, and for some breeds of cats). Can these be sorted into a pile or the winter look versus the summer look? If you have a pet and can feel these changes that are even better.
Where do animals go during the winter? Here is a place to start answering this question: https://www.youtube.com/watch?v=Tz9Ps9D8weU.
Find images of birds that migrate versus those who stay behind. These can be sorted or compared. Are there obvious differences between those birds that choose to spend winter in a warm climate versus those who remain close to home?
Although there are fewer mammals that migrate, some do make the treks to warmer climates for the winter months. For example, caribou, whales, and some bats will head south for the winter. Do not imagine that the caribou are heading to Florida, as they will head south within their normal range so they are still relatively close to the arctic.
Who hibernates and who remains active during winter months? First, help your child understand what is hibernation. When animals hibernate their breathing, body temperature, heart rate, and metabolism (think of all the chemical reactions that keep cells alive and functioning) slow down. With this slow down, energy stored in fat is used very slowly and keeps the animal alive. It is kind of like a sleep, but it might be worth distinguishing hibernation from sleep for most children. Some animals, like chipmunks, skunks, raccoons and opossums are deep sleepers rather than hibernators. That is, these animals sleep for long periods, but will wake to forage for food on warmer days.
Compare warm-blooded and cold-blooded animals. Warm-blooded animals, or mammals and birds, regulate their body heat by converting food into energy. These creatures, like us, must be active to keep warm.
Hibernating, warm-blooded mammals are distinct from cold-blooded animals (fish, reptiles, amphibians, spiders and insects). These animals cannot control their body heat, so their body temperature is the same or close to the air around them. In winter, these animals are in a state of brumation, or their body temperatures drop to near freezing and their breathing slows. Some frogs and insects actually do freeze, but their bodies can produce something like antifreeze that is protective of the surrounding tissue. Here is more information:
For those animals that continue to remain mostly active, what do they eat? What do deer, elk, rabbits, raccoons, opossums, and porcupines eat during the winter versus the summer? What foods are still available during the winter months (moss, twigs, leaves, small rodents, insects)? What foods are no longer available (berries, grass, green leaves, more insects). Compare animal diets in winter versus in other seasons.
Some birds have feathers that grow over their feet and legs to help them stay warm. These additional or longer feathers may also help them to walk on snow or ice. See if you can find images of the Ptarmigan. Other animals have paws or extra fur that serve the same purpose
Examine animals’ tails. Do some appear to be better suited for wrapping oneself up and keeping warm?
Where do animals live during the winter months? Where do frogs, bears, hedgehogs go for their winter naps? Some live in burrows or tunnels underground, others live just under the snowpack while some live under logs or the hollow parts of trunks of trees. Some, like earthworms, just dig deeper into the soil. Compare animals’ winter homes.
Within in a specified period of time (5 or 10 minutes depending on your child’s attention span) count the number of birds at a bird feeder on a day when the temperature is below freezing. Count the number of birds during the same time period at a bird feeder when the outside temperature is above freezing? Is there a difference? Consider creating a graph of these observations. This exercise includes a second element or reading a thermometer. If you have a barometer or can find information about barometric pressure, consider counting birds at the feeder when the pressure is high versus low.
Do the same with squirrels. How many can you see on a really cold day versus a warmer day? Be sure to keep the food offerings similar and the same amounts for a good comparison.
If you have an opportunity to see birds flying in formation and migrating for the winter, use a compass to determine what direction they are headed in.
Look up statistics about hibernation or migration. Pick an animal such as a bear or Monarch butterfly. How long does the bear hibernate? How much weight does it gain before hibernation or how much weight does it loose over the winter months? What happens to its breathing pattern or heart rate. How far does the Monarch butterfly migrate? How long does it take? How many butterflies make the journey?
Find an area covered with wet leaves outside. Remove those leaves. Is anything going on beneath? Slugs, snails, and spiders keep up their regular activities. What about ants and bees, can you see any (they hibernate)?
If you live in an area with snow, invite your child to create “feet” that can walk on top of the snow versus feet that sink in the snow. For example, create something that looks like a deer’s leg and hoof. Find a stick and attach an object that resembles a hoof on the bottom. Now walk this in the snow. It should sink in. The legs and hooves of deer are not well adapted to walking in snow or across the ice and that is why deer will hover in areas well protected by the trees and not venture far during the winter months.
Next, create a polar bear’s paw. This might involve a large sponge. Walk that on the snow. It should remain on the surface. What characteristics of these two different feet contribute to sinking in versus remaining on the surface? Wider pads or paws act like snowshoes. Create something that resembles a bird’s or duck’s foot, a rabbit’s foot, or other creatures. I have not suggested specific materials here as I think it is helpful if your child looks for pictures of these various animals’ feet and then imagines how to create replicas herself.
Hairy or furry feet also help on snow and ice and prevent slippage. Observing what worked for animals probably led to the invention of what sorts of tools or equipment (snowshoes)?
On a really cold day, place a cup of birdseed on a piece of cardboard. After a designated period of time (2 or 3 hours), how much of the seed is left? Repeat on a warmer day, leaving the seed for the same period of time and measuring the remaining amount after the same period of time. On which day did the birds eat more seed, the cold or warmer day? Leave out food for squirrels or chipmunks. On Which days will they eat more?
Experiment with layers of insulation. Step outside briefly on a chilly day without a sweater or jacket. How does it feel? Next, add a layer, better? Try layers of different materials. Is a cotton shirt better than a down jacket? Down feathers are precisely what keeps many birds warm during winter as down holds air which keeps in heat. (Not all down jackets contain real feathers, but the principle is the same).
What could you do to help explain how fat or blubber helps to keep animals warm when the temperature drops. Here is an experiment you can try. You may find images of these steps online to help. You will start with 2 Ziploc bags, some Crisco shortening, and a bowl of very cold water (add ice if you do not think this will make it so cold that it will hurt). Fill one of the Ziploc bags about 1/3 full of Crisco. Turn the other bag inside out and place it inside the Crisco-filled bag. You should be able to zip the bags together. This forms a “glove” that your child can stick her hand into while also covering the gloved hand in the fat. Next, ask her to place her bare hand into the water and describe how it feels. Then give each a chance to wear “blubber” and describe how it feels. Is there a difference? Think of other forms of insulation that you could substitute for the fat. Do you have a hand full of cotton balls or feathers around?
Build your own hive, nest or cave for hibernating. What would you want in there if you were going to sleep for several months? If you were like a squirrel, instead of storing nuts for winter, what would be your preferred winter foods?
Visit a library and take some time to search for, look at and check out many of the terrific books about animal lives and their adaptations during winter months. Both fiction and nonfiction books are available and will provide hours of fun and learning during times this winter when your child is stuck indoors.
Enjoy winter, it can be a beautiful and instructive time of year! Here are some additional activities to usefully fill hours of time: http://www.pleasantestthing.com/2014/01/winter-outdoor-activities.html.
Build a snow fort and experience the same living arrangement as a number of animals.
Visit a zoo and see how the animals cope with winter cold.
To stay warm, lots of animals huddle together. Have a family huddle or group hug for warmth and just the sheer joy of it!