In very cold climates, animals need excellent insulation to stop their body heat from escaping. This may be on the outside, in the form of dense hair, fur or feathers, or on the inside, in the form of a thick layer of fat or blubber.
The North Pole and South Pole are covered with snow and ice, the North Pole and South Pole are really cold all the time, we identified polar animals and where they live, learned penguins live at the South Pole and polar bears live at the North Pole.
Polar bears lose so little heat to their environment that they are almost invisible to thermal imaging cameras. But a recent study at the University of Buffalo found that polar bears have also evolved genes that produce more nitric oxide than other bear species. Nitric oxide is a signalling molecule and one of the mechanisms it controls is whether cells use their available nutrients to produce metabolic energy, or simply convert it into body heat. Polar bears seem to be able to divert more of their body’s resources into generating heat. This relies on them getting enough fuel for this process and adult polar bears have a high calorie diet; they mostly eat seal blubber.
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.
