If you have watched Arctic nature documentaries, you may have noticed that polar bears pursuing their prey can travel at impressive speeds and make rapid turns on snow and ice. A recent study of polar bear paws comparing them to brown bears, American black bears, and sun bears reveals how they can stop quickly on the ice.
Polar bears have more foot fur and smaller paw pads than other bears. The paw pads have microscopic bumps called papillae which are as much as 1.5 times longer than those of other bears. Friction experiments show that the taller papillae increase the surface area in contact with the ground giving more traction on slippery surfaces. The smaller size also reduces heat loss through the paws. When we were in Alaska, I learned that native Americans living there for generations could tell the color of the bear by looking at its paw prints in the snow or mud.
The polar bear is not just a brown bear with a white coat. There are design features in polar bears that equip them to live in an ice and snow environment. The design of polar bear paws is only one of the features allowing them to survive in an environment where no other bear could. Sun bears don’t have papillae at all because they would be useless in the bears’ tropical habitat.
The more we study the design of animals, the more examples we see of specialized equipment enabling life to survive everywhere on Earth. These examples remind us that “we can know there is a God through the things He has made” (Romans 1:20).
— John N. Clayton © 2023
Rerence: American Scientist magazine for January/February 2023 page 15, or americanscientist.org