Stripes serve as camouflage for zebras in motion

BBC : The zebra’s striking striped coat has long mystified scientists, because it does not blend into the background as do the coats of many other animals. Now Martin How of the University of Queensland in Australia and Johannes Zanker of the Royal Holloway University of London have developed computer models to analyze photographs and video footage of the animals’ coat patterns as they move. What they found was that the stripes on their backs and sides create visual illusions, like a spinning barber’s pole whose stripes appear to move up or down the pole, or a rotating spoked wheel, which can appear to be moving in the opposite direction. The researchers propose that the illusory effects of the motion signals generated by different parts of a zebra’s body are meant to confuse observers, such as biting insects in the air or predators on the ground. Their findings could be applied to military camouflage and possible other uses.