Pigeons have surpassed mammals in brain efficiency.

A gram of pigeon brain consumes, on average, 2.5 times less glucose than the brain of mammals of comparable size, and 3.5 times less per neuron, the German scientists found. The reason for such a high energy efficiency of avian neurons has not yet been precisely determined, but, most likely, the matter is in the histological features of the nervous tissue and the temperature of the brain.