April 1, 2014

Why Zebras Have Stripes


Stripes could protect us from biting flies, scientists claim as they explain zebra markings

Biologists believe they have unravelled the evolutionary mystery of how the zebra got its stripes claiming the markings protect them from biting flies.

A team from the University of California, Davis, believe zebras’ unusual monochrome markings evolved in order to repel biting insects, such as horseflies and tsetse flies, which tend to avoid striped surfaces.
The study, published in the journal Nature Communications, mapped the geographic spread of seven different species of zebras, horses and asses and their subspecies and recorded the thickness, location and intensity of their stripes on several parts of the body.

It compared the animals’ geographic reach with other variables such as woodland habitats, the range of predators, temperatures and the numbers of ectoparasites such as tsetse flies.

After examining where the striped animals and variables overlapped the scientists ruled out all but one of the existing explanations, that of avoiding blood sucking flies.

"I was amazed by our results," said Prof Caro.
Unlike other African hooved mammals living in the same areas as zebras, zebra hair is shorter than the mouthpart length of biting flies making them particularly susceptible to these insects, the team found.
Posted by Jill Fallon at April 1, 2014 2:18 PM | Permalink