Birds pack more cells into their brains than mammals

New research reveals the secret behind the remarkable intelligence of some bird species

Related: Blind cave fish evolved a shrunken brain to save energy

Calling someone "bird brain" used to be considered as an insult. Birds' brains are very small compared to those of mammals, and what's more, they lack the heavily wrinkled cerebral cortex, which is characteristic of the human brain, and widely believed to the seat of intelligence. It was, therefore, widely assumed that birds aren't very clever creatures, but recently this has started to change.