The zebra, with its white and black stripes, is a truly iconic animal. Since the 19th century, many scientific theories have emerged explaining the reason for these stripes. Some theories have been refuted, but one very notable is currently the most accepted by the scientific community. So why does a zebra have stripes?
Zebra belongs to the family of equidae, which includes a single genus Equus and three subgenus - horse, donkey, and zebra. The genus Equus comes from North America, where 4 million years ago the horse separated from the ancestor of a donkey and a zebra. The genus Equus inhabited Eurasia about 3 million years ago, and the zebra separated from the donkey about 2.8 million years ago, and arrived to Africa about 2.3 million years ago. In Africa, the zebra itself has been further divided into several species, of which there are three today, namely the steppe zebra, the mountain zebra and the Grevy's zebra.
The zebra is actually black with white striped fur. The stripes are unique to each individual and their patterns are hereditary. Many scientific theories have emerged regarding the zebra stripes. The famous British scientist Alfred Wallace applied the theory of somatolysis in 1896, i.e. covering coloration of animals that are in their natural habitat. However, this theory was questioned 25 years earlier by another famous British scientist, Charles Darwin. Today we know for sure that lions see the silhouette of a zebra before the stripes and that zebras tend to flee and not camouflage.
Another camouflage theory, the so-called confusion theory, says that the lion does not correctly estimate the direction of the zebra's movement and also that the number of individuals in the herd looks smaller than it actually is. But this theory has also never been generally accepted.
The theory of aposemantism says that the color of an animal gives predators a warning signal that prey is dangerous for them, such as poisonous. Zebras are quite aggressive and can dig and bite. This theory may work on smaller predators, but it certainly doesn't work on lions.
The theory of social function states that stripes play a role in recognition, socialization, and that they provide information about an individual's ability to mate. However, the zebra's ability to mate in relation to stripes was also later questioned.
According to the theory of thermoregulation, the stripes serve to cool the animal. The black stripes naturally warm more than the white ones, creating convective currents that cool the animal. In addition, the zebra is able to erect the fur on black stripes, while leaving it lying on white.
In general, the most accepted theory today is the theory of insect protection. Horseflies are particularly dangerous to the equine family in Africa because they transmit highly contagious deadly diseases. As early as 1930, it was discovered that flies had a lesser tendency to sit on a black-and-white striped surface than on a solid surface. Later, it was also found that horses dressed in a striped blanket make flies less prone to sit on them. Exactly the same behavior of flies has been proven in humans.