How the zebra got its stripes - biting flies as selective agents in the evolution of zebra coloration

Zebra stripes have traditionally been thought of as an adaptation against detection by vertebrate predators such as lions and hyaenas. A different hypothesis is suggested: that the stripes are an adaptation against visually orienting biting flies and act by obliterating the stimulus presented by a large dark form, which is important in host-finding by many Diptera. This hypothesis is supported by some indirect evidence, and by a field experiment in Zimbabwe in which biting fly catches were compared on moving and stationary black, white and striped models. Striped models caught significantly fewer tsetse (Glossina morsitans) Westwood and other flies (including tabanids) than solid black or white models, but this difference was much reduced in the presence of olfactory attractants.