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Adaptations That Animals Made to Cold Environments

All living things are specially designed to survive in a particular climate or environment.

Special behavioral, physical and physiological characteristics necessary for survival are known as adaptations. Animals living in continually cold climates are uniquely adapted for their frigid surroundings, while other animals only make temporary changes as the climate around them changes. In climates with different seasons, the onset of winter is signaled by the drop in temperature, and shortening of daylight hours. Animals in these environments have very different ways of dealing with their cold environments.

Adaptations for the Poles
- Polar bears have black skin and several layers of fur to protect them from cold.
  
  Animals living at the Arctic and Antarctic poles must be prepared for extremely cold environments year round. Common characteristics of mammals found at the poles include rounder and bulkier body shape, and shorter ears, muzzle, legs and tail. These physical traits conserve body heat. In addition land mammals will have very think fur, and a layer of stored fat, both for insulating the body. Similarly, Emperor Penguins have densely packed feathers and down, with outer feathers that overlap making them waterproof. Polar bears have hollow hairs to trap warm air, and black skin that attracts the ultra-violet rays of the sun. They also have an undercoat covered with an outer coat, to protect them while swimming. Arctic foxes and hares both have large feet that are covered with fur, for better movement over the snow.
Adaptations for Cold Water
- Rounded bodies and thick blubber layers insulate marine mammals in water.
  
  Marine mammals like seals, walruses and whales possess special adaptations for the icy waters. Heat from warm-blooded animals is lost more quickly in cold water than in cold air. A rounded body shape and very thick blubber layers are necessary to guard against the escape of body heat escaping.
Seasonal Migration
- Many birds migrate in flocks away from their home during the winter months.
  
  Many species of bird will leave their home to migrate to a warmer climate for the winter, returning in spring. They will choose to fly away as days grow shorter, and food supply becomes more and more scarce. Depending upon the species, migration patterns may be the same from year to year, and be hundreds of miles away. This is also true for some species of invertebrates like the Monarch butterfly.
Hibernation
- Many mammals in seasonal climates will grow a thicker coat, fatten themselves up, store food, and some even hibernate to escape the harsh effects of cold winter weather. Smaller animals loose heat more quickly, and require more energy to stay warm. As a result, many small critters like mice, voles, chipmunks, squirrels, badgers and even bats will choose to hibernate. They do so by lowering their heart rate, respiration, and body temperature, and simply sleep the winter months away. In Alaska, Brown bears will retreat to their dens during the long harsh winter months, and may hibernate for as long as 6 to 7 months. Cold-blooded reptiles also need to hibernate during winter months. This is due to their inabiltiy to regulate their own body temperature, as well as lack of available food sources like invertebrates, and small animals or birds.
Invertebrates
- In seasonal climates, many invertebrates dies at the end of the summer. However, their eggs, larvae or pupae stay hidden away during the winter awaiting spring. For example, spiders will die after laying eggs into a whitish cocoon that thousands of new spiders will be released from in spring. Others species of invertebrates like caterpillars, certain butterflies, slugs, snails, mosquitoes, wasps and bumblebees will spend their winter months in a state called torpor. These invertebrates release special chemicals called glycerol into their bodies which prevents them from freezing.

Animals & Science