A Wilder View: Why do zebras have stripes?

Posted at 3:34 PM, Mar 29, 2023

MISSOULA - Sometimes we answer questions that are quite complex and other times our questions are more black and white — like zebras.

This edition of A Wilder View takes a look at why zebras have stripes.

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

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

Theories suggested it helped them camouflage or that stripes served as an identity nametag 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 horseflies 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 and then coats with small checkerboard patterns.

Horseflies 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.

It is a complicated answer to a black-and-white question.