theme park in France has established novel and environmentally-friendly way of keeping its grounds free of litter. It has selected and trained six "intelligent" rooks to pick up rubbish and keep park clean. Rooks are members of crow family and are up to 47cm in length. The clever birds will be put to work at Puy du Fou theme park in west of France. They have been trained to pick up cigarette ends, paper and other things people throw on ground. The birds pick up the litter and deposit it into special trash can, which then delivers some bird feed as reward. The more litter the birds put in trash can, the more food they get.
The head of theme park, Nicolas de Villiers, explained rationale of using crows to the AFP news agency. He said there were several reasons for deploying crows. He said: "The goal is not just to clean up, because visitors are generally careful to keep things clean, but also to demonstrate that nature itself can teach us to take care of environment." Crows are highly sociable and intelligent birds. Some biologists say they are as smart as seven-year-old child. Mr De Villiers said: "In affectionate, supportive atmosphere, they like to communicate with humans and establish relationship through play." The crows are speedy workers and can fill bucket with rubbish in less than 45 minutes