With the Kids: Animals use different means to adapt to winter conditions

Many of us experienced a special winter wonderland in the past week. Because it was only temporary, the snow was special and fun.

But imagine if you had to spend the entire winter surrounded by snow. How would you survive? Surely you would have extra layers of clothing, probably even a waterproof outer layer. Would you want your layers to be fun and colorful, or blend in with the background?

Animals don’t have a choice, they need to have a camouflaged outer layer. It is critical for them to stay hidden as they try to avoid predators or as they hunt for their next meal. The ones that spend the winter in snowy habitats need to have white camouflage to be most effective at staying hidden.

Some animals stay white year-round like snowy owls and mountain goats. Others change their coats so they can match the changing environment. A local example of such a two-toned critter is the short-tailed weasel. Brown in summer and fall to blend in with the green or brown grass, this small hunter turns white every year if it lives in a snowy area. The only thing that doesn’t change color is the black tip of its tail.

Unlike chameleons and octopi that can change their colors in minutes, it is a much slower process for birds and mammals. That is because feathers on birds and fur on animals are like our fingernails – they are actually dead tissue. Since the tissue is not alive, the animal cannot change the color. Instead they must grow an entirely new set of fur or feathers. For an animal like a rabbit or weasel, the process takes about 10 weeks. That works out pretty well since their habitat rarely goes from brown to white overnight. Their patchy mid-season coloration helps them blend in with the patchy environment.

All animals that live in cold climates also have extra layers of fur, just like we pile on the layers when we spend time outside in the cold. Dense under-fur keeps the warmth in against the skin while the outer layer is mainly to keep the moisture out. Many mammals have oily fur on the outside that works for them like Gore-Tex or plastic rain ponchos work for us by causing most water droplets to roll off.

Some animals that live in cold climates also have hollow fur on the outside. This provides the aminal insulation, just like double- or triple-paned windows to keep the warm air inside a house. Other animals also have very thick layers of blubber or fat to help keep them warm.

Because it is so hard to survive in the coldest climates with lots of snow, many animals adapt to it by leaving, or migrating. Birds can fly to warmer climates for the winter months, but mammals need to find their way to lower elevations or to more protected habitats like forests or canyons. Some mammals migrate every year, others only when the weather is particularly harsh. Still other animals find a safe and cozy place to spend the winter and go into a period of dormancy. Those animals that cannot be easily woken during this dormant period are actually hibernating. Most animals sleep less deeply though and can be woken. However, since there is not much food available in the winter and it takes a lot of energy to wake up from dormancy, they are best left to sleep so they can survive until spring

How some animals deal with the cold

 • The sea otter has the thickest fur on the planet with 1 million hairs per square inch. The human head, in comparison, has about 625 hairs per square inch.

 • Beluga whales, which live in frigid northern waters, have the thickest blubber with up to a foot of fat. Blubber is firmer and far thicker than the fatty tissue of land mammals and is laced with connective tissue.

 • The farthest annual migrations on record are those of the Arctic tern. These birds fly about 24,000 miles a year migrating from the northern hemisphere to the southern, maintaining an endless summer.