Unlike polar bear’s elongated skull, large feet, and huge paw they have got small ears—perhaps one of many adaptations to cold climates. Polar bears inhabit the Northern Hemisphere where the temperature drops down to minus 30 degree Celsius in winter. Their small ears are perfectly adapted to surviving the frigid Arctic weather. Now we’ll see why do polar bears have small ears as compared to its mammoth size.
Why Do Polar Bears have Small Ears?
- According to Allen’s rule, animals that live in colder climates possess shorter ears, limbs, and other appendages in comparison to those that survive in warm habitats, and when it comes to ears, polar bears fit the rule.
- The reason why polar bears have small ears is that they live in some of the coldest habitats and as such they must have relatively low ratios of surface area to volume. In order to survive in the Arctic polar bears ought to conserve as much heat as possible.
- Polar bears should have low surface area to volume ratios so that they have a minimum surface area by which they dissipate heat, enabling them to store more heat. If they had larger ears just like their grizzly cousins, they would lose heat much quickly and consequently die of cold.
Read More: Polar Bear Physical Characteristics
Compared to its sense of smell, the polar bear hearing sense is not that sharp. Nonetheless, scientists suggest that the polar bear sense of hearing is pretty similar to humans’.
In fact, they can hear in the 11,200 to 22,500 Hz range but it is best at 8,000 and 14,000 Hz. According to scientists polar bears share their hearing sense with dogs on the lower end that is 125 Hz. However, on the high end, dogs are well ahead of polar bears (and humans)—hearing up to 60,000 Hz.
Andrew E, Derocher, a leading polar bear researcher, is a professor in the department of Biological Sciences at the University of Alberta and author of numerous articles on large Arctic mammals. He writes in his book, Polar Bears—A Complete Guide to their Biology and Behavior;
I have seen only one polar bear with large ears. Unfortunately, I was laughing so hard about the poor bear’s ears that I failed to measure how big they were or take a picture. Ears are not something I would normally measure, but in this case it would have been interesting. I am not sure but my guess is that the large ears were a throw back to grizzlies, which have much larger ears than their polar bear cousins. Uncharacteristically and perhaps unkindly, I wrote “Dumbo” on the bear’s capture sheet.
Well, there is a reason why polar bears don’t have acute sense of hearing. That is, polar bears particular hunt ringed seals which produce sounds like chirps, growls, yelps, and barks in the water. Seals produce these sounds below 2,000 Hz.
Thus, polar bears need not to hear at extremely high frequencies. Scientists aren’t sure what the role of hearing is when the polar bear hunts seals. Perhaps it might be too early to conclude anything with regard to polar bear’s sense of hearing.