I'll begin this thread with one of my personal favorites, Corvids:
They are considered the most intelligent of the birds, and among the most intelligent of all animals, having demonstrated self-awareness in mirror tests (European magpies) and tool-making ability (crows, rooks)—skills until recently regarded as solely the province of humans and a few other higher mammals. Their total brain-to-body mass ratio is equal to that of great apes and cetaceans, and only slightly lower than in humans.
More corvidae content to come, also: Timneh parrots, cockatoos and bald eagles.
Prohibited: Canada geese. Do not post about them here, don't even mention them. No one cares.