Why Do Zebras Have Stripes?

June 20th, 2017

It certainly does look very special: a white horse-like animal with decorative black stripes. But is it just a freak of nature or is there something more serious behind the design of a zebra?

Many African animals have stripes on their bodies or spots like the leopard but none of these patterns contrast as starkly as the zebra's. Researchers have long struggled to explain the purpose of the zebra's unique black-and-white coat. Some have suggested that the stripes may help zebras to hide and escape from lions and other predators, avoid nasty bites from disease-carrying flies, or to control body heat by generating small-scale breezes over the zebra's body when light and dark stripes heat up at different rates.

Now, researchers based at the University of California, Los Angeles (UCLA) have produced one of the most comprehensive zebra stripe studies. The findings suggest that torso stripes may do more to help zebras regulate their body temperature than to avoid predators and Tsetse flies.

The team found that the plains zebras with the most-defined torso stripes generally lived in the Northern, equatorial regions, whereas those with less-defined torso stripes were more common in the Southern, cooler regions— a finding that supports the thermoregulation explanation.

Still, the researchers have not experimentally tested the theory that black and white stripes may generate small-scale breezes over a zebra's body, and some researchers don't think stripes can actually create this effect.

The researchers plan to test their thermoregulation hypothesis, either by studying the behavior of air currents over zebra pelts, or by implanting wild zebras with temperature sensors. If they are granted permission to do so we will be hearing about the results soon.