Eyes On Their Back

Radford’s team got the idea for the experiment from nature. Some animals have markings called eyespots to protect themselves from predators. “Some butterflies have eyespots on their wings,” says Radford. “And they’re found on other animals, like fish and birds too.” Sometimes these fake eyes make an animal look like a larger or more dangerous animal, like an owl or a snake. That makes a predator think twice about attacking it.

Eyespots may also trick a predator into thinking it’s been seen by its prey. The predator gives up the hunt because it believes it’s lost the element of surprise. Radford wondered if painted-on eyespots would fool predators like lions and leopards in the same way. No one had ever tried using this trickery to protect livestock. So Radford’s group decided to test it out.

The scientists got help from farmers in Botswana. “We drove around to farmers and herders, talked about their problems with predators, and asked if they wanted to help with the experiment,” says Radford.

The scientists created eye-shaped foam cutouts and coated them with paint. Then they stamped large eyes on the rumps of some of their herd. An equal number of cattle got stamps in the shape of an X. And another equal number of cattle were unmarked.

At the end of the four-year study, 15 of the unmarked cows had been killed by predators. Four of the cows marked with X’s were killed. But all the cows marked with eyespots survived!

“We were surprised that something as simple as eyes painted on cows’ bums stopped these impressive predators,” says Radford. 

Other researchers are now testing fake eyes on cattle in Brazil and India. Radford says he hopes the study helps people and animals live together: “Sometimes, experiments produce cool results that give us hope.”