The six rooks pecking at litter within the Puy du Fou theme park in Les Epesses, France, aren't unwelcome pests: They're part of the staff. As AFP reports, the trained birds have been dispatched to clean up garbage and cigarettes butts from the park grounds.

Rooks are a member of the corvid family, a group of intelligent birds that also includes ravens and crows. At Puy du Fou, an educational amusement park with attractions inspired by various periods from French history, the rooks will flit around the park, pick up any bits of litter that haven't been properly disposed of, and deliver them to a receptacle in exchange for a treat. At least that's how the system is set up to work: The full team of six rooks has only been on the job since August 13.

Employing birds as trash collectors may seem far-fetched, but the experiment has precedent. The Dutch startup Crowded Cities recently started training crows to gather cigarette butts using a vending machine-like device. Once the crows were taught to associate the rig with free peanuts, the machine was tweaked so that it only dispensed food when the crow nudged a cigarette butt resting on a ledge into the receptacle. The cigarette butts were eventually removed, and the birds figured out that they had to find the litter in the wild if they wanted to continue receiving their snacks.

Crowded Cities had planned to conduct more research on the method's effectiveness, as well as the potentially harmful effects of tobacco on crows, before bringing their vending machines to public spaces. Puy du Fou, meanwhile, has become one of the first—if not the first—businesses to fully implement the strategy on a major scale.

Even if it doesn't prove to be practical, Puy du Fou president Nicolas de Villiers told AFP that cleaning up the park is only part of the goal. He also hopes the birds will demonstrate that "nature itself can teach us to take care of the environment."

[h/t AFP]