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The fat on polar bears' fur protected them from freezing ice, which can make them more visible to prey. Experiments with bear fur have shown that it counteracts freezing as well as ski pads against freezing and slipping during ascents. Researchers believe that substances from bear fat could be used to improve anti-icing coatings, particularly on airplanes.
How was wool tested for its ability to prevent freezing?
Scientists have been trying to understand how polar bears (Ursus maritimus) manage to avoid freezing even though they dive into the water to hunt, and their outer coat is at the same temperature as the environment. It turned out that the sebum of polar bears has high levels of cholesterol, diacylglycerol, and branched-chain fatty acids, as in most mammals. However, no lipid was found in the sebum of bears squalene, which is found in human sebum. Chemists have found that squalene can actually bind better to water and ice, which is why it is absent in bears.
To test this hypothesis, they conducted an experiment in which they placed an ice cube on bear fur and other materials, checking how hard it would freeze. In it, polar bear fur and ski pads had similar properties and easily peeled off the ice cube. But human hair, which had sebum with squalene on it, peeled off even worse. The worst was the bear fur, which had been washed of sebum. The fat to protect against freezing distinguishes polar bears from other polar animals, penguins, which have a special feather structure for this.
