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How Do Polar Bears Stay Warm?

A polar bear's fur and blubber help it to keep warm.
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  • Written By: Mary McMahon
  • Edited By: Bronwyn Harris
  • Last Modified Date: 13 November 2014
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Polar bears are found in very cold parts of the world where temperatures can drop as low as -20° Fahrenheit (-29° Celsius). Without proper protection, this weather can be deadly, so polar bears stay warm by utilizing their thick fur and fat, or blubber. Polar bears have evolved along with other Arctic animals to take advantage of minimal warmth, and can sometimes actually become too warm because their bodies are so efficient at trapping heat.

A polar bear's fur is the first step in keeping warm. Polar bears actually have two types of fur: long oily guard hairs and short insulating hairs. Polar bears stay warm by combining the properties of these two hairs. The guard hairs are actually hollow, and look like very small tubes of glass. The hollow guard hairs trap warmth and bring it close to the skin while also providing an oily outer layer that prevents the polar bear from getting wet. The insulating hairs trap heat close to the skin, much like insulating underwear on humans.

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Blubber also helps polar bears stay warm, by providing an insulating fat pad on certain parts of the body. While polar bears do not use blubber as efficiently as some Arctic animals, it certainly adds a layer of protection and can also be used for energy when food sources are minimal. Blubber is distributed unevenly across the bear's body, and ranges from 2 to 4 inches (5 to 10 cm) in thickness. Blubber also combines with the air trapping guard hairs to keep polar bears afloat in the water.

Scientists have also seen polar bears stay warm by using the snow. Snow crystals trap small amounts of air, and polar bears will burrow in the snow to create an insulating blanket which, while cold, is still warmer than the outside world. This is sometimes combined with a biological process called winter sleep, which slows down metabolic processes. Winter sleep is not quite hibernation, as the bears can be woken, but it does create lower energy demands on the body that will keep the bears warmer.

Using this variety of physical and physiological adaptations, polar bears stay warm during even the coldest winters. In the summer, polar bears shed part of their winter coat and blubber, but they may overheat in extremely warm weather. Polar bears stay cool in the heat by spreading out to increase their surface area and going for dips in the Arctic waters, which are still chilly, even in the summer.

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anon322467
Post 22

Albino polar bears look like black bears, but they aren't, they're black polar bears!

anon241840
Post 15

No, polar bears are brown! They turn yellow during the cold season, and then molt when summer comes.

anon60687
Post 8

Contrary to what Al Gore says, polar bears are also great swimmers. It is not uncommon for a polar bear to swim as much as 100 miles while hunting.

While we're on the subject, the polar ice caps are not melting! That is junk science that is being put forth by Al Gore in order to justify those bogus carbon taxes. Polar bears are not dying off in large numbers, or drowning due to the melting ice caps either.

Nasa photos reveal that the polar ice caps shift as part of a natural cycle. The ice caps expand and contract in this dynamic cycle. Polar bears numbers have actually increased dramatically within the last three decades.

anon60532
Post 7

i find it disgustingly depressing that people don't believe in evolution and that they think atheists created this massive hoax. i am religious but I'm not an idiot. evolution is a fact and you cannot deny it.

i think people who regret the knowledge that science has led to are just fearful of their god and ignorant that not everything you read is real. keep on living in your fairy tale world.

NeverTheLess
Post 6

While on the subject of polar bears, I told you not to eat that, didn't I?

Polar bear liver is toxic. Just research polar bear liver to see the facts.

anon60352
Post 4

Ever think, maybe God just made them this way as he knew they going to live in very cold weather?

anon60334
Post 3

Polar bears did not "evolve" as you stated. Indeed, "evolution" is a hoax perpetuated by atheists who stupidly reject the existence of God who created all life forms, created the Big Bang, and created all time, space and gravity laws.

anon25792
Post 2

How come some polar bears are brown and some are white?

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