Klein has studied crows (as opposed to Crowes, as in my maiden name) for 10 years and considers them to be very intelligent, with a body/brain ratio similar to chimpanzees. They demonstrate their intelligence by activities such as placing peanuts in traffic lanes so that cars can run over them and crack the shells, after which they wait for the light (!) and walk onto the road to retrieve the nut. Even more astonishing, they seem to learn this behaviour from each other.
Klein set out to dramatically illustrate crows' intelligence by teaching them to put coins in a vending machine to get peanuts. The picture shows a couple of the trained crows doing their thing on the vending machine. His hypothesis is that these highly intelligent animals could be trained to perform many tasks – picking up garbage would be just a first example. What’s very powerful is that after training a few of them, the training could be passed around a large number of crows.