The question "why do zebra have stripes?" is one that has been asked a thousand times.
According to a Namibian folk story, the zebra was once completely white. During a fight with a baboon over the right to drink at a waterhole the zebra kicked the baboon so hard that the zebra tripped into a fire scorching his white coat with thick black bars.
Fables asside, why would zebra need their distinctive colouration?
In a relatively plain environment such as the African savannah, it would seem that any prey animal with striking pattern would have a death wish. Some of the most revered terrestrial predators in the world live on the African continent, lions, hyenas and leopards to name a few, perhaps a dusty, plain camouflage would serve to protect the animal from being seen?
Some species of zebra are abundant in number (although some are gravely endangered) and range throughout Africa in various habitats. Black and white stripes should, therefore, confer a significant advantage to zebra when in surviving to a successful breeding age.
The most common theory is that the black and white vertical striping hide the zebra in any long grass. A similar theory is suggested for the striping pattern of tigers, although this is more widely accepted due to the denser vegetation and mottled shadowing of the tiger's habitat.
Another camouflage theory suggests that the striping may camouflage the zebra within its herd. A group of disruptively camouflaged objects moving against each other are hard to focus on. Any predator would struggle to discern an individual zebra.
It has been noted that the black and white stripes of zebra could serve to ward off biting insects.
Zebra were used as pack animals instead of other equids, such as horses and asses, by colonists due to their apparent immunity to horsefly bites and the trypanosomiasis disease that they carry.
Zebra stripes are unique to each individual, much like human fingerprints. Perhaps zebra can recognise family or specific group members by their unique patterning? It is yet to be fully understood whether zebra use patterning as a means of identification.
Ultimately, the actual function of zebra stripes is probably down to a mixture of various reasons, all further pushing the patterning to the extreme contrasting stripes we can witness today.