The Corvid family (ravens, crows, magpies, jays) of birds is widely regarded as the smartest in the world.
Other than whiskeyjacks (gray jays) we only have ravens up here, and they are huge! Both are very intelligent. It's great entertainment to watch a bunch of ravens tease and torment the local dogs. Illegal to shoot them though.
i think birds could be pretty much be placed into two categories -- predatory(the hunters) and non predatory(the scavengers) -- given a chance, i would eat any one of them...
speaking of what predatory birds are capable of, check this eagle out, i know its been around a while -- but crows can do the same...