This is an article about a study done with ravens that proved that they can plan in advance, just like people do, but what is interesting is that the scientists are considering doing it with parrots so let's all hope they do it so we can learn from it. I don't know if parrots can plan a day or more in advance but I know for a fact they are smart enough to figure out strategy to get what they want.
http://www.npr.org/sections/thetwo-way/ ... y-can-plan