Function Over Fashion

Question: Why do zebras have stripes?

Answer: The best-supported hypothesis: It’s a natural insect repellant.

The vast, sun-drenched savannahs of Africa are riddled with seemingly unsolvable mysteries. On one hand, the mystifying lost cities of Gedi in Kenya or Thulamela in Zimbabwe baffle archaeologists and anthropologists alike to this very day. On the other hand, scientists, zoologists, and curious minds have perpetually pondered the purpose behind simpler, more blatant questions—like why zebras have black and white bands adorning their sleek coats.

I mean, how could you not wonder? What could have possibly happened in their evolutionary process to make zebras stick out like a sore thumb in a desert climate riddled with bloodthirsty beasts? At first glance, one might assume zebras adapted to blend into some sort of barren, mountainous setting composed of powdery snow or igneous outcrops—not one dominated by green trees, shrubs, grasslands, and arid plains. It’s almost like a cruel joke by nature, some sort of reverse-Darwinism, where these domino-hued equines evolved to announce their presence to every potential predator in proximity.

For centuries, a range of theories circulated in the scientific community regarding the nature of zebra stripes, but none of them were ever proven—until recently. It was 1981 when researchers added a layer to the zebra stripe saga with a new theory—that zebra stripes are for "shooing flies"—and, since then, numerous studies have substantiated this theory with solid evidence, marking it as the best-supported hypothesis existing today.

For example, a 2012 report published in the Journal of Experimental Biology propagated that zebras’ distinctive black and white patterns serve as a deterrent to horseflies and tsetse flies—which are notorious for transmitting diseases. These pesky, dangerous insects struggle with landing on a zebra's coat: "A zebra-striped horse model attracts far fewer horseflies than either homogeneous black, brown, gray, or white equivalents," the researchers wrote. They concluded that the disruptive visual effect of the stripes throws off the precision of the flies' landing attempts, acting as a natural shield—or bug repellant—against these airborne nuisances and the diseases they spread.

This newfound evidence differs from one of the oldest and most widely accepted theories, which suggests that zebra stripes evolved as a form of camouflage. The popularity of this theory might sound surprising when a zebra pattern doesn’t exactly blend into the African environment, but it has long been posited that the alternating black and white patterns create a visual disruption that confuses predators and makes it challenging for them to single out an individual zebra from the herd. Purportedly, the keen eyes of a lion or hyena can get disoriented by the optical illusion of stampeding stripes—it becomes difficult for the predator to choose what piece of prey they ought to give chase to. Unfortunately, there’s never been enough clear-cut evidence to ring the "camo theory" in as the real deal.

Then there’s the theory of "thermal regulation." With the blazing sun casting its golden rays upon the open plains, Africa is a theater of heat—to say the least. Thus, scientists have speculated whether the zebra's stripes play a crucial role in temperature regulation. A popular hypothesis suggests that the temperature difference between the black and white stripes creates air currents—akin to a natural air conditioning system. As the black stripes absorb more sunlight, the air above them warms up, creating upward air currents that draw cooler air from the surrounding environment. This subtle dance of thermoregulation could provide zebras with a cooling mechanism, helping them endure the scorching African heat.

Finally, the "visual communication" theory has always been a top runner in the race. Zebras are highly social animals, and the distinctive black and white patterns on their coats may serve as a form of visual communication within the herd. Each zebra's unique stripe pattern might function like a fingerprint, helping individuals recognize one another in the vast expanse of the savannah—which is especially crucial during times of danger, when zebras band together in a coordinated defense against predators.

5 Fun Facts About Zebra Stripes:

• Zebra stripes taught the American Navy how to give their enemies the ol’ "Razzle Dazzle": In World War 2, the American Navy adopted zebra stripe camouflage for their battleships—also known as "razzle dazzle" camouflage—to make it difficult for an enemy to estimate a ship’s range, speed, and heading. Breaking up the lines of a ship also interfered with the enemy’s ability to identify the class of the ship and its distance. By doing so, the opponents often believed they were opposing larger, more powerful ships than they were.
• No two zebras have identical stripe patterns: Much like human fingerprints or a snowflake, no two zebras will wear the same prints on their coat (further supporting the visual communication theory). Each zebra's coat is a distinctive work of nature's art, making them easily distinguishable from one another.
• Zebras don't just have black and white stripes: Zebra’s also possess fainter "shadow stripes" in between their bold bands of black and white. These subtle markings contribute to the mesmerizing complexity of their coat patterns.
• Baby zebras have brown stripes—not black: Baby zebras, known as foals, are born with brown and white stripes instead of the iconic black and white. As they grow, their stripes darken.
• Zebra stripes may stick out in the African climate, but that might be why they can see one another so well in low-light conditions: Zebras are known to be crepuscular animals, meaning they are most active during the dawn and dusk hours. The unique contrast of their stripes may provide advantages in low-light conditions (further supporting the "camo theory").

Take a front row seat to a real-life zebra "fashion show" during our Ultimate Africa: Botswana, Zambia & Zimbabwe Safari adventure.