The Genius of Birds

by Jennifer Ackerman

Clearly there’s more to a brain than mere size. But the truth is, birds have long had a bum rap in the size arena. Contrary to the cliché, the brains of many birds are actually considerably larger than expected for their body size. This is the result of an extraordinary process that also gave rise to our own oversized brains—although through a completely separate evolutionary path. Bird brains range in size from 0.13 gram for a Cuban emerald hummingbird to 46.19 grams for an emperor penguin. Tiny indeed next to the 7,800-gram brain of a sperm whale, but compared with animals of roughly the same size, not so small at all. The brain of a bantam bird weighs about ten times as much as the brain of a similar-sized lizard. Consider a bird’s brain relative to its body weight, and it comes out more like a mammal.