It has taken 150 years but scientists have finally figured out why zebras have stripes and it all has to do with flies, or more specifically, deterring biting flies from landing on the black and white animals. How scientists arrived at their findings is possibly as interesting as their discovery.
For years Tim Caro, a biologist of University of California at Davis, has pondered the role of zebra stripes,
The Atlantic noted. In a final attempt to understand the phenomenon, he and a team of experts trekked to a stable in southwest England where captive zebras were living alongside domestic horses -- the ideal scenario for his experiment. After observing the two different species, the team then dressed the horses in zebra-striped coats. They then noted that the striped pattern appeared to deter horseflies.
"We found that zebras and horses received a similar number of approaches from horseflies, probably attracted by their smell — but zebras experienced far fewer landings," Caro wrote for
Quartz. "Around horses, flies hover, spiral and turn before touching down again and again. In contrast, around zebras flies either flew right past them or made a single quick landing and flew off again."
After cloaking the horses in the comical striped costumes, the scientists observed a similar trend.
"When we placed black coats or white coats or striped coats on the same horse so as to control for any differences in animal behavior or smell, again flies did not land on the stripes," Caro explained. "But there was no difference in landing rates on the horse’s naked head, showing that stripes exert their effect close up but do not impede fly approaches at a distance."
The findings open up doors for research however, as Caro noted in a paper published in
Plos One, the reason as to how exactly the striped pattern deters flies from landing is still to be established.
"One idea is that the stripes set up an optical illusion that disrupts the expected pattern of movement the fly experiences as it approaches the zebra, preventing it from landing properly. Another idea is that flies don’t see the zebra as a solid entity but a series of thin black objects," he wrote for Quartz.
Meanwhile, the discovery could greatly benefit the horse-wear industry, having the "potential to make riding and horse maintenance less painful for horse and rider alike," Caro concluded.