Monkeys pay for porn.

Nature says it’s true: Rhesus monkeys will trade items of value – in this case, juice – in return for sexy monkey booty shots:

The researchers gave captive male rhesus macaques two options: a drink of cherry juice, or a different-sized shot of juice and the chance to look at one of a range of pictures of their troop members for just over half a second.

By varying the amounts of juice, the team worked out how much the monkeys valued each image. “Monkeys are basically juice experts; they’re very sensitive to the differences,” says team member Robert Deaner.

Monkeys would take a juice cut to look at powerful males’ faces or the perineum of a female, Deaner and his colleagues report in Current Biology. But to persuade the monkeys to stare at subordinate males, the researchers had to bribe them with larger drinks.

…[T]he juice-to-picture exchange rate was highest for images of female rears. “Virtually all monkeys will give up juice to see female hindquarters,” Deaner says of his male subjects. “They really value the images.”