I Didn’t Know That ...

Q: Why do elephants have such big ears?

A: Surprisingly, the ears are to help the beasts stay cool. Large animals have a much harder time dissipating internal heat than do small ones because their skin area is proportionally smaller. As a general rule, skin area increases as the square of height, while volume increases as the cube. If one animal is twice as tall as another, for example, it has four times as much skin, but eight times the volume. Elephants also don’t sweat, so they have a hard time dissipating excess heat. But their large ears are laced with many blood vessels that allow heat to escape into the air. That is why bush elephants that live in the savannas of Africa have larger ears than the African and Indian forest elephants that live in relatively cooler climates.