Researchers looked at why zebras have those iconic black and white stripes.
The scientists found the stripes could be an evolutionary response to pests such as horseflies and tsetse flies, a University of California, Davis news release reported.
Past research has shown that these flies tend to avoid landing on black and white striped surfaces, but were not sure if this phenomenon was the evolutionary driver behind zebras' unique pattern.
In the past researchers have suggested a number of functions for the striped pattern, including; "Disrupting predatory attack by visually confusing carnivores; A mechanism of heat management; Having a social function; Avoiding ectoparasite attack, such as from biting flies," the news release reported.
Researchers looked at the distribution and fur pattern of a number of zebra, horse, and donkey species and compared the results with regional factors such as "woodland areas, ranges of large predators, temperature, and the geographic distribution of glossinid (tsetse flies) and tabanid (horseflies) biting flies," the news release reported.
The researchers were able to rule out all of the factors as driving factors for fur pattern except for biting flies.
"I was amazed by our results," lead author Tim Caro, a UC Davis professor of wildlife biology, said in the news release. "Again and again, there was greater striping on areas of the body in those parts of the world where there was more annoyance from biting flies."
The distribution of tsetse flies has been well documented in Africa, but insects such as horseflies and deer flies are not as well documented. The researchers mapped out the ideal breeding conditions for these insects, dubbed tabanids.
Zebras living in regions with high concentrations of these pests have shorter fur than other local hooved animals, making them more susceptible to biting flies. This could explain why only zebras have such dramatic stripes.
"No one knew why zebras have such striking coloration," Caro said. "But solving evolutionary conundrums increases our knowledge of the natural world and may spark greater commitment to conserving it."
In the future researchers hope to gain insight into why biting flies tend to avoid striped surfaces.
