The wide paws prevent sea ice from breaking by distributing the polar bear's weight as it walks.
Polar bears have strong legs and large, flattened feet with some webbing between their toes, which helps with swimming and walking on ice. The polar bear's footpads have a kind of “non-slip” surface, allowing them to get traction on slippery ice. The bear's large size reduces the amount of surface area that's exposed to the cold per unit of body mass (pounds of flesh), which generates heat. This is especially important while swimming and during the frigid Arctic winter. Polar bears also have a thick layer of fat below the surface of the skin, which acts as insulation on the body to trap heat.
Polar bears predators skin#
The skin under the polar bear's fur is actually black this black is evident only on the nose. The bear's outer layer of fur is hollow and reflects light, giving the fur a white color that helps the bear remain camouflaged. Many of the polar bear's physical adaptations help it maintain body heat and deal with its icy habitat. A newborn polar bear weighs only about 1.5 pounds. Bears can weigh about 50 percent more after a successful hunting season than they do at the start of the next most of this additional weight is accumulated fat. A large male can weigh more than 1,700 pounds, while a large female is about half that size (up to 1,000 pounds). Male polar bears are much larger than the females. They are about seven to eight feet long, measured from the nose to the tip of their very short tail. Off southern Labrador near the whelping patch, harp seals accounted for 90% of diets.Polar bears are the largest carnivorous land mammals on Earth. Throughout Davis Strait, harp seals comprised 50% of bears' diets, consistent with the increase in the harp seal population in this region. However, ringed seal consumption declined throughout the 1990s concurrent with progressively earlier ice breakup, while the proportions of bearded and harbour seals increased, suggesting reduced reliance on ice. In western Hudson Bay, ringed seals accounted for about 80% of intake in the early 1990s, indicating the importance of foraging in ice-covered habitat.
Ringed seals accounted for ≥98% of diet in the Beaufort Sea. Although polar bears consumed ringed and bearded seals throughout their range, diets differed greatly among regions. We used quantitative fatty acid signature analysis of polar bear adipose tissue to estimate their diets in the 1980s/90s across three major regions of the Canadian Arctic: Davis Strait ( n = 70), western Hudson Bay ( n = 217) and the Beaufort Sea ( n = 34), using a database of the major prey species in each region ( n = 292). climate change) and demographic factors that influence prey selection. Yet, because they are so wide-ranging and difficult to observe, there are few quantitative data on polar bear diets or on the ecological (e.g. Polar bears ( Ursus maritimus) are broadly distributed in the Arctic and, as such, have the potential to provide information about changes in ecosystem structure and functioning over broad scales in time and space.
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