Science and TechAnimals and Insects


Why do zebras have stripes?

Theories suggested the stripes helped them camouflage, or served as identity nametags for zebras to recognize each other.
Posted at 8:21 PM, Apr 13, 2023

There’s fierce competition in the wild, but you're more likely to see lions face off with panthers on the gridiron than in the great outdoors. 

So why do zebras masquerade as NFL referees in the wild? The question,"Why do zebras have stripes?" is one that’s long stumped researchers. 

Theories suggested the stripes helped them camouflage, or served as identity name tags for zebras to recognize each other. But newer research suggests the stripes help them repel those pesky horse flies. 

Researchers from Bristol University studied the benefits of zebra stripes by examining how horse flies behaved around zebras and horses. 

They put patterned coats on horses and discovered those in striped patterns were less bothered by flies than horses in black or white coats. One of the lead researchers told us their greatest finding was the intensity of striping on the animal correlates with the number of horse flies it attracts. 

In updated research, the team looked at more patterns and found horseflies are attracted to large darker objects and are less attracted to dark broken patterns. 

Horses with gray coats experienced the most horsefly landings, followed by horses in coats with large black triangles, then coats with small checkerboard patterns. 

Horse flies were least attracted to horses with striped coats, and stripes with higher contrast meant even fewer flies. 

The researchers say zebra stripes are sharply outlined and thin because this specifically deters horseflies. 

A complicated answer to a black and white question.