The evolutionary driver for zebras’ black-and-white stripes has been identified as biting flies, including horseflies and tsetse flies, which tend to avoid black-and-white striped surfaces.
Research led by Dr Tim Caro, from the University of California, mapped the geographic distribution of seven species of zebras, horses and asses, and compared this to a range of variables. They found that there was greater striping on animal coats in areas where there was more annoyance from biting flies.
Zebras are particularly susceptible to fly bites because their hair is shorter than other mammals living in the region. Further research could investigate this characteristic and the reasons why biting flies avoid striped surfaces in the first place.
Read more at University of California, Davis