Eli5: Why do small animals like squirrels not lose appendages to frostbite when temperatures reach below freezing, and they walk around on ice and snow all day?
In: Biology
Evolution.
We are adapted to living in the hot grasslands of Africa. That’s why we suck at living in the cold. If you grabbed another animal from that same area and made it wander around Alaska in December it would soon die.
First, animals in cold areas have fur adaptations, both long guard hairs and small ‘fluffy’ hairs You can find these between the toes of may animals that have developed their winter coats.
Second – animals have different levels of bloodflow in their furthest extremities. Birds have very little bloodflow through their feet, meaning when exposed to cold they aren’t as impacted as other animals (although they will still stand on one foot holding the other close to their bodies to conserve heat…and cold weather birds have feathers on their feet for warmth). Just like low bloodflow, some animals address it with high levels of bloodflow.
Third, there are other adaptions like ‘pads’ on paws. Think about a dog’s foot. Those pads are composed of keratin (the same substance that makes up hair ,fingernails, and horns) collagen, and a special fat. Think about the thickest most calloused hands you’ve ever seen. Do you think that they could a hot plate a second longer than normal before the heat soaked through? The pads on a dog’s feet are much thicker than that, plus with fat and collegen mixed in. This works good for cold surfaces, hot surfaces, rough surfaces, etc.
Fourth, when it gets REALLY cold, animals seek shelter, frequently curling up in a ball to protect those extremities.
Latest Answers