Scientists think they have solved how the zebra got its stripes – and the answer is far from black and white.
They say the distinctive monochrome pattern keeps the animals cool under the hot African sun.
It is thought that differences in the way the dark and light fur absorb and give off heat create refreshing currents of air.
The theory comes from US scientists who compared the stripes of zebras from 16 different sites with their living conditions.
This included the weather, the vegetation and the presence of lions and biting flies.
The analysis revealed a clear link between temperature and coat pattern, with zebras from the hottest areas having the stripiest bodies.
It has been argued the stripes’ main function is to create an optical illusion that dazzles lions.
But the University of California researchers said that if this was the case, they would have expected to find more lions in areas in which the zebras had few stripes.
They also noted that lions are particularly good at catching zebras, so if the stripes were used as a defense mechanism, it wouldn’t work well.
The researchers were also sceptical of recent research which has suggested the stripes are used to repel biting flies.
And while it is often said the stripes act as camouflage by making the animals harder to spot in constantly changing woodland light, the Californian scientist point out that zebras spend much of their time in the open of the savannah.
Those in the tropics also had the darkest stripes – and so should have the best natural air conditioning, according to the Royal Society journal Open Science.