Science

New Study: Why Do Zebras Have Stripes?

Zebras Have Stripes
12019 / Pixabay

A team of researchers conducted a series of interesting experiments to try to figure out why zebras have stripes all over their bodies. This question has been irritating many people since their childhood, but now a new study published in the journal PLOS ONE supposedly sheds light on zebras’ unique stripes.

Scientists have wondered about the evolution of zebras’ two-tone stripes for over 150 years. A team of researchers published the findings of their study of how those stripes develop and possibly even why zebras have stripes in the first place.

There have been many theories about the origin of zebras’ stripes. Some suggested that zebras have stripes so they can scare away predators, while others suggested that the stripes help the animals regulate their body heat. Still others theorized that the stripes have some sort of social function. Despite all these theories, scientists couldn’t come to an agreement.

Now a group of researchers from the University of Bristol and University of California, Davis believe they have uncovered evidence which suggests zebras have stripes to deter blood-sucking insects and other parasites. Professor Tim Caro and  Dr. Martin How of the University of Bristol and their colleagues say they found this evidence by observing and investigating the behavior of horse-flies which live around captive zebras and domestic horses in North Somerset.

Using video analysis techniques, the researchers said they found that horses and zebras attracted horse-flies at the same rate, which means zebras’ stripes don’t deter flies from a distance. However, their analysis also showed differences in flies’ approach speeds between horses and zebras.

“Horse flies just seem to fly over zebra stripes or bump into them, but this didn’t happen with horses. Consequently, far fewer successful landings were experienced by zebras compared to horses,” Caro said in a statement.

“Stripes may dazzle flies in some way once they are close enough to see them with their low-resolution eyes,” How added.

They also conducted an experiment which involved observing horse-fly behavior around horses dressed in a variety of colored coats, including black, white and zebra-striped. When horses wore coats with striped patterns, there were fewer horse-fly landings than when they didn’t wear stripes.

Horse-flies are an annoying and widespread problem for domestic animals, but researchers believe this problem could be solved with anti-fly coats which resemble zebra stripes. More importantly, this research suggests that would work.

Horse-flies in Africa tend to carry dangerous diseases like trypanosomiasis and African horse sickness which usually end in death. The researchers who conducted the study on zebras believe this is why zebras adopted behavioral defenses and developed stripes to defend themselves.