The Mystery Of Why Zebras Have Stripes Has Finally Been Solved

Zebra stripes bedazzle biting flies, reducing their ability to make controlled landings

by GrrlScientist for Forbes | @GrrlScientist

NOTE: originally published under the title: “Why Horses Should Wear Striped Pajamas”

Throughout the centuries, there have been many explanations why zebras have stripes and horses don’t.
(Credit: Igorowitsch / CC0)

A newly published paper by behavioral and evolutionary ecologist, Tim Caro, who studies animal coloration at the University of California at Davis, and an international team of researchers reports that zebras evolved stripes to reduce predation by biting flies. This conclusion came from an elegant series of experiments using horses, captive plains zebras, and horses wearing striped pajamas, which revealed that striped surfaces prevent biting flies from making a controlled landing (ref).

So many curious people, so many curious ideas

From scientists such as Alfred Russel Wallace and Charles Darwin to popular writers such as Rudyard Kipling, people have long pondered why the zebras are striped whereas their close cousins, horses, are plain. Over the last 150 years or so, the public has entertained a variety of explanations for zebra stripes ranging from providing camouflage (ref), confusing predators (ref & ref), and signalling to other zebras (ref: US / UK), to reducing overheating (ref), but…