In the Okavango Delta, in northern Botswana, lions and leopards hunt by surprise. If they sense that their prey has already seen them, they almost always abandon the attack. Ecologist Neil Jordan, from the University of New South Wales, decided to take advantage of exactly that.
For four years, his team painted fake eyes on the rear ends of hundreds of cows in 14 herds. The result: of 683 cows with painted eyes, none died from predators. By contrast, 15 of 835 unmarked cows died, as did 4 of those with only a painted cross.
The researchers themselves warn that the experiment has limitations, because the painted cows were always mixed with unmarked cows. Even so, the finding opens up a simple and inexpensive way for livestock farmers to protect their animals.