why do polar bear have thick fur


A weekly dose of education in the ocean. This is the second in a five-part series about the polar bear s adaptations to the Arctic environment. Polar bears are supremely to their environment they have a number of traits that help them cope with snow, ice, and below-freezing temperatures. They are more likely to overheat than to become hypothermic, because of the following characteristics. Florian Schulz, from his book,
To The Arctic. Large Size. Polar bears are the world s largest land-based carnivore. Males can get up to 1500 lbs (almost 700 kg) even bigger than their hulking cousins and this helps them retain their body heat. As Dr. Andrew Derocher explains in his recently published book, Polar Bears, A Complete Guide to Their Biology and Behavior, this is because large animals have a higher, so they lose less heat through their skin. This is an adaptation common to many species in cold habitats. Small Ears and Tail. that stick out also affect the volume to surface-area ratio and cause more heat loss as discussed above. The polar bear s small ears and tail offer less surface area than large ears or tails, and help maintain body warmth. Fat. Polar bears have a layer of fat that can be four inches (10 cm) thick. Although their fur is the primary source of insulation, the fat helps keep heat in as well. Like other marine mammals, the milk of polar bears is extremely high in compared to other bears or land mammals. The fatty milk helps small cubs, who are more vulnerable to the cold, put on critically important body weight quickly. Small cubs are more vulnerable to cold than adults, but quickly put on weight thanks to mom s fat-rich milk.


Photo by, Creative Commons License High Calorie Diet. Most bears are opportunistic omnivores they eat whatever they can find, and plants figure largely in their diet. While polar bears will eat seaweed when stuck on shore, they only do this in desperation. Their true diet is pure meat and fat, from seals and whale carcasses. Meat and fat have more calories than plants, so polar bears get the most out of every bite, and every ounce of hunting effort expended, to build their important fat layer discussed above. Thick Fur. Except for the tip of the nose, polar bears are entirely covered in fur. They have a very thick undercoat, which is even denser than the coats of other bears, as well as longer guard hairs. This them from the cold, even when they are in water. Their fur is also hollow and transparent. (It was once thought that polar bear fur could also conduct UV light to the animal s skin but this has been proven to be. ) Their fur has another use as well: the hairs reflect light, making polar bears look white and helping them camouflage among the snow and ice. Water Repellant Fur. Polar bear fur sheds water like a Gore-Tex jacket, so even after a swim, they don t stay wet long. According to, oils in the hair help with this, and the polar bears are very diligent in drying themselves by shaking and rolling in the snow when they come out of the water. Water has a very high heat capacity, which causes it to channel heat out of the bear s body, so the faster they dry, the faster they stop losing heat. Large Anti-Slip Paws. Polar bears have enormous paws!


On land, they are like, spreading the bear s weight and helping them move across soft snow and thin ice. On ice, they keep the bear from slipping: they have footpads covered by papillae (small soft bumps) and claws that are short, thick, and curved. The paws also are covered in fur for both traction and warmth. A polar bear s paws serve as snowshoes with anti-slip soles, and double as paddles for swimming! Photo by Srvban via, Creative Commons License. maindiv {background-color:#7bc9ea;width:500px;\”}. maindiv p {color: white; font-size:18px; font-family: Helvetica,Arial,sans-serif;} Do you have polar bear questions? Because we have answers forб б (February 24-28)! Send your questions toб б today, and be sure to tune in for ourб б on Friday, February 28 at 1 p. m. EST to get your answers! ItБs no exaggeration to say that are built to survive Б and enjoy Б the cold. б From their to their thick layer of body fat, theyБre the kind of animals that actually become more active as the temperature drops. While temperatures below zero with snow and wind may sound brutally cold to some in the south, terms like blizzard and polar vortex come to mind, for polar bears itБs just everyday weather. IБve watched bears stretching and rolling in the snow in weather that you and I would need layers and a heavy parka to БenjoyБ. Almost every aspect of the polar bears design is engineered for warmth. б Their bodies are designed to be lined with a cozy layer of fat, which can be up to 3. 4 inches thick. б This fat not only helps polar bears keep warm, but acts as an energy store for slow hunting periods.


Although polar bears appear white, their fur is actually transparent, and just appears white because of the way it scatters light. б This coat, of course, is also designed to keep the bears comfortable well below zero. б While their thick undercoat prevents heat loss, their top coat Б or guard hairs Б consists of hollow hairs that are longer and lightly, to help repel water, since bears are marine mammals. Along with their physical attributes and physiology, their lifestyle and food preference is also designed to keep bears warm: so is their lifestyle. б For the most part, bears wander, walking fairly slowly for extended periods. б This helps keep them warm, but also minimizes the amount of energy their using to travel, rather than swimming or running. б Their primary prey, ringed seals, is also very high in fat, which polar bears efficiently burn or metabolize to stay warm. For polar bears, staying cool is a much greater challenge than staying warm, especially as Arctic summers get longer. б They have been seen digging into mud and kelp beds to try and cool down, and often spend a lot more time resting. б They are built for life on the cool sea ice, and the loss of that ice due to climate change is the greatest threat to these bears. ThatБs why WWF is working to ensure that polar bears and other ice-dependent species have a home in the future, one that fits their design: the, a patch of resilient sea ice high in the Arctic. б To help support our work, and Coca-Colaб will until March 15, 2014, to a maximum of $1 million USD (Canada and U. S. only).

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