Hey, Bird Brain!

Birds have very large brains for their body size. New research is helping scientists understand how they work, and came to be. One part of a bird’s brain, the cerebellum, controls their amazing flight capabilities – their spatial awareness, allowing sudden direction changes through tree branches, or their ability to chart migration over thousands of miles. PET scans taken pre- and post-flight have shown very high brain activity in the cerebellum, especially the neural pathways connected to the eyes. CT scans of the skulls of modern birds and their fossil ancestors help explain how their brains evolved. The brains of early birds stayed the same size, as their bodies shrank. The brains of many bird families, like crows and parrots, then began to grow even larger. Island, nocturnal and insect-eating birds also grew larger brains, to manage difficult environments and chase flying prey. To control what birds do when not flying—building elaborate nests, singing complex songs, even solving puzzles—requires another part of the brain: the cerebrum. Other early bird fossils show that the cerebrum grew in size first, while the sophisticated flight anatomy, and the cerebellum to control it, developed later. Taken together, their cerebrum and cerebellum make a remarkable brain, which gives birds their even more remarkable qualities. So if anyone ever calls you a bird brain… well, say thank you!