I am very sorry that I could not shoot a shocking picture - on the Khimki forest crow flew and carried in its beak ... a plastic cup. And it is not empty, but with some content, and carried over the edge, so that the content is not shed. Well, is not a model of intelligent behavior?
Judging by the lack of results, the task of finding signs of intelligent behavior many birds seemed too complicated ...
Yes, indeed, to observe and photograph an example of rational behavior of any bird, you must carefully observe them - and do not miss the opportunity when they show something interesting. However, there is another way: put the experiments!
For example, you can leave on the table in the courtyard of food wrapped in a package, and watch as the birds will get it there. And then you can think of and more complex experiments, for example, put a piece of meat in a transparent tube or a narrow slit, where it can not be removed with the help of the beak, and next put a piece of wire. And watch out, if anyone will think of your yard crows proposed use tool!