up cigarette ends, paper and other things thrown on the ground. the birds pick up the litter and put it into a special trash can. this delivers bird food as a reward. the more litter the birds put in the trash can, the more food they get.
the head of the theme park explained why it is using the crows. he said there were several reasons. he said: "the goal is not just to clean up...but also to demonstrate that nature itself can teach us to take care of the environment." crows are very sociable and intelligent birds. they may be as smart as a seven-year-old child. the theme park head 