Bird cognition is really cool! I know keas have been known to do all these crazy things. There is a video somewhere where there's a kea and a crow solving all these different puzzles. Each one has one puzzle that they solve much faster than the other. However, the one the raven does better is simply a matter of flexibility: the kea keeps trying to for the object in the appropriate hole to get the reward, and it can't get the stick in quite the right position simply because of the shape of its body. On the one the kea does better, the raven repeatedly walls around the puzzle before figuring out what to do, whereas the kea instantly figures it out.
Ravens are pretty great, as Mr. Poe would tell you. Apparently they can also imitate words.