Like the vegetarian who can't resist the occasional burger, the otherwise herbivorous gorilla might succumb to cravings for its evolutionary cousins, a new study hints.

While some zoo specimens are known to eat meat, wild gorillas eat only plants and fruit, along with the odd insect—as far as scientists know (see video of wild gorillas feasting on figs).

But a recent study found DNA from monkeys and small forest antelopes called duikers in the feces of wild African mountain gorillas in Loango National Park in Gabon.