Study Shows Giving Your Horse Zebra Stripes Will Help Deter Biting Flies

Biting flies come out in droves during the summer months, and the hungry pests pose a particular risk for horses. Horse flies, deer flies, and biting midges see our horses as a tempting buffet. They swarm their faces, backs, and bellies looking for a good place to feast. They leave behind painful bites, and sometimes those bites spread deadly diseases.

Fly control is a priority for every horse owner, and it's also something we struggle with. There are ways to minimize flies at your barn, and some horse owners are turning to a more creative solution. A study shows that a zebra's stripes could be the key to protecting horses from biting flies.

Why Do Zebras Have Stripes?

Scientists have multiple theories as to why zebras have stripes. Some say the black and white pattern helps keep the equids cool in scorching temperatures, and others credit the stripes with being good camouflage. The real reason could be a combination of several benefits, but there's not enough evidence to give us a definitive answer.

A study published in PLOS One, however, shows zebra stripes could have evolved to protect the species from biting flies. It also suggests that same concept can be used to protect horses and other animals.

The Experiment

For the study, researchers observed three captive zebras and nine monochromatically colored horses in adjacent fields in Britain. Horseflies are an annual problem for the area, and researchers were looking for how the flies responded to the different groups of animals.

From a distance, it looked like the flies were equally interested in both the zebras and the horses. Researchers could see swarms of flies around both groups.

With a closer look, however, they discovered something interesting. The flies swarming the zebras seemed to get confused when they attempted to go in for a bite. Researchers observed that the flies failed to slow down and either missed the zebra altogether or bumped into the skin and fell away.

During 5.3 hours of observation, the three zebras didn't receive a single fly bite. The flying pests buzzed by their ears and swarmed above their bodies, but they didn't get close enough to bite. 

In the next field over, the uncovered horses weren't as lucky. Biting flies got to them 239 times in 11 hours of observation.

To continue the study, researchers also covered horses in coats—one black, one white, and one with zebra stripes. In a 30-minute time frame, over 60 flies touched down on the horses with the solid black and solid white coats. At that same time, only five flies landed on the horses dressed in stripes. 

From these observations, researchers theorize that a zebra's trademark stripes deter flies at a close range. They're still not sure why it happens, but their findings show zebra stripes could help horse owners protect their horses from biting flies.

With this encouraging evidence, many horse owners have invested in zebra-striped fly sheets. The stripes are an added defense to protect horses from bites and prevent the spread of disease.

h/t: Science Mag