Zebra stripes not for camouflage: study

Toronto: The striking black and white stripes that adorn zebras do not camouflage the animals from their predators, a new study has found, dispelling the long-held belief that the stripes protect them from being spotted.

"The most longstanding hypothesis for zebra striping is crypsis, or camouflaging, but until now the question has always been framed through human eyes," said lead author Amanda Melin, an assistant professor at the University of Calgary in Canada.

"We, instead, carried out a series of calculations through which we were able to estimate the distances at which lions and spotted hyenas, as well as zebras, can see zebra stripes under daylight, twilight, or during a moonless night," said Melin.

In earlier studies, the researchers showed that the zebra's stripes provide an evolutionary advantage by discouraging biting flies, which are natural pests of zebras. In the new study, they found that stripes cannot be involved in allowing the zebras to blend in with the background of their environment or in breaking up the outline of the zebra, because at the point at which predators can see zebras stripes, they probably already have heard or smelled their zebra prey.

"The results from this new study provide no support at all for the idea that the zebra's stripes provide some type of anti-predator camouflaging effect," said Tim Caro, a professor at the University of California - Davis.