Scientists believe they may have finally figured out why zebras have stripes.
It’s a mystery that has confounded scientists for 75 years: just why do zebras have stripes? The most popular theory says that the stripes help to camouflage the animal while in a herd, with one individual being far more difficult to discern from the next.
This has never sat well with scientists as lions, hyenas, and other predators generally rely on smell to locate their prey from a distance, and up close the striping pattern does little to confuse.
Now scientists say they may have figured out what gave zebras their stripes, and it has nothing to do with fooling lions; it has everything to do with fooling flies.
In a study published in the journal Public Library of Science ONE, researchers from the University of California at Davis and the University of Bristol say that the stripes actually serve to confuse the vision of biting flies such as horseflies and tsetse flies.
To find out, researchers from both universities dressed up a bunch of horses in cloaks. One group had a solid black cloak, one group had a solid white cloak, and a third group had a zebra patterned cloak. What they found was that horseflies were equally attracted to each group of horses from a distance, but up close, the zebra patterned horses received less successful landings from flies than the other two groups.
Research fellow at Bristol University Martin How told the Associated Press that stripes might be a defense mechanism against biting flies in zebras. “This reduced ability to land on the zebra’s coat may be due to stripes disrupting the visual system of the horse flies during their final moments of approach,” he said.
“Stripes may dazzle flies in some way once they are close enough to see them with their low-resolution eyes.”
Once close in, horseflies tended to either miss or bump into and bounce off the horses covered in zebra cloaks. In general, those horses received far fewer successful landings--and far fewer bites--than the unclothed and single-color horses.