Hummingbirds Use Complex Brains to Power Their Impressive Movements

Image: Shravans14/Wikimedia

Hummingbirds may have tiny brains, but they’re unusually powerful. A new study, published in Current Biologysays the way the tiny birds fly — flitting abruptly in every direction and using rapidly-beating wings to hover — requires a lot of brain power.

Hummingbirds are the only species of bird that’s able to truly hover, and to do it they’ve evolved extremely large breast muscles and a specialized wing shape. They’ve also developed a deeply complex brain, which research says is necessary for multidirectional flight.

Most animals move primarily in a forward direction. This includes humans; though we’re capable of moving relatively quickly in a number of directions, instinct still pushes us forward. For instance, when we’re threatened we tend to turn and run in the opposite direction. Most terrestrial animals do the same, and many aren’t even capable of moving backward or side-to-side.

Image: Charles J. Sharp/Wikimedia

The hummingbird, though, is different. In the part of the brain responsible for interpreting visual stimuli, the lentiformis mesencephali, the researchers found that hummingbirds displayed no definitive front-to-back instinct. Instead, hummingbirds move equally in every direction.

The researchers also discovered another big difference in hummingbird brains. They exhibit more of a response to fast movements than they do to slow ones. That makes sense when you consider just how fast hummingbirds can move — about 385 body lengths per second. For comparison, an F15 Eagle fighter jet flies at about 45 body lengths per second.

When you’re moving that fast, one wrong move can mean serious trouble, so a hummingbird has to navigate instantaneously.

The researchers’ motivation for examining the birds’ brains wasn’t just ornithological interest, though. They hope that understanding how hummingbirds move, and think, will help inform technological innovations in flight and robotics.

Perhaps it’s time to redefine the term “bird-brained!”