Did you ever see the show about crows by David Suzuki The Nature of Things. When that show passed on TV my cat Nike watched the whole show. We had filmed him and put it up on you tube sitting in a chair his head going back and forth following the crows, it was really funny. Unfortunately when we took it down the computer it was in gave out.
In that episode they showed how crows broke their nuts by dropping them so the cars would run them over, then recuperating them when the lights were red. They would bring them to the where the lights were because they knew the cars would have to stop, they had learned this through observation.
I have a whole family of blue jays here and they scream at around 7, I really hope the neighbors don't complain.