Found this really interesting, although I was never really in much doubt at the "intelligence" of these increadible animals. Wendroid is right to point out the magpie example of self awareness, although I would like to know the relative brain mass index of these birds. I have heard of very similar things with that whole family, with Miner birds being notorious for having mastered a small vocabulary.

Had a quick look around for some info on this topic and came accros a great resource : http://ngm.nationalgeographic.com/geopedia/Animal_Minds

I was looking for the study conducted on elephants (Payne, Katherine. National Geographic: "Elephant Talk." National Geographic: USA. August 1989) where they studied the infrasound communications of wild elephant herds. This one always struck me as significant, because it whispers to us of a vast and efficient network that would have spanned large areas of the African continent. I always thought of it like whale song, although being propogated through a denser medium it would travel faster and further (?). So maybe at some point during their ancient past, the elephant herds were in constant communication, following signs of water and congregating on grazing grounds and to mate/socialise.... I think this (like the dolphin superpods that have only recently been described in any great detail) shows of a formidable intelligence.