Rooks trained to pick up cigarette butts

Park president Nicolas de Villiers said the idea came from one of their falconers, Chris­tophe Gaborit, because the birds are intelligent and “given a conducive environment, like to communicate with humans and establish a playful relationship”.

Mr Gaborit invented  a box which delivers a crunchy snack when the rook places a butt inside. “The birds are very fast, they can fill a bucket in less than three-quarters of an hour,” he told France Info.