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A unifying theory of winged locomotion could explain the magical mid-air maneuvers of birds and insects, and guide the design of flying robots.

Using high-speed video, biologists modeled how hummingbirds and hawkmoths use asymmetrical flapping to make slow, mid-air turns. The model predicted how five other flyers turned at full speed, hinting at a universal turning technique for flying creatures.

“It’s basically an exponential damping system,” said Ty Hedrick, a University of North Carolina animal aerodynamics expert. “The strength of braking increases in proportion to speed.”

Though scientists understand the principles underlying many flight-enhancing physiologies, from birds’ hollow bones to dragonflies’ flexible wings, the biomechanics of turning was in many ways a mystery.

Researchers were unsure whether different species used fundamentally different mechanisms, or variations on a basic theme. Hedrick’s findings, published Thursday in Science, describe a common solution shaped by evolutionary pressures in the 150 million years since dinosaurs took to the air.

Though the dynamics probably can’t work at large scales â?? building-sized robotic birds won’t ever be as agile as a swallow â?? they could be harnessed in small drones used by explorers or the military. Compared to the average hummingbird or fruit fly, such craft are now clumsy and unstable.

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