Why zebras have stripes

In Wired, a scientist set out to determine why zebras have stripes. He investigated all of the more common theories. He was able to use evidence to support findings that shot down most of the existing hypotheses.

He found that stripes did not help camouflage the zebra or help it hide from other predators.

Stripes were not a warning to predators.

They did not confuse predators.

They weren't really used for social recognition or temperature control.

He did find one key benefit to stripes:

“I knew from the literature that certain kinds of biting flies didn’t like landing on black and white surfaces,” he says. He also knew that the insects were attracted to movement. So, he would put on the pelt, trudge for an hour, and have his assistant count the number of tsetse flies that had landed on him. For science, he did the walk again, draped in a wildebeest hide.

And? “I really started to see results at this point,” he says. The flies did not like the stripes! “It was an elevating experience, at last after ten years working on this project I started to see a positive effect on one of these hypotheses.” He did more experiments, including setting up striped fly traps (no more walking down dusty roads). With each new experiment, the evidence lined up to support the anti-insect hypothesis. Eventually, Caro and his colleagues did a map analysis, overlaying the ranges of various biting flies and insects with the places where zebras, and their non-striped cousins like the Asiatic wild ass, ranged. “It’s a slam dunk, if you like,” he says. “You find striping where you have high biting fly abundance.”

Perhaps I should start wearing pinstripes for our next walk in the woods!

Here is a link to the full article:  Wired: The Man in the Zebra Suit Knows the Secret of Stripes