Most birds that swoop over ocean waters have one thing in common: dark wings. Now scientists think they know why. Dark feathers absorb more heat, which improves flight efficiency, allowing these birds to fly faster and longer than those with lighter-colored wings.
Researchers had investigated this mystery before. Whereas most scientists have focused on the typical functions of colors, such as how birds’ feathers can help them with mating, hiding from predators, or finding food, others have looked at how darker feathers might improve flight efficiency. These experiments, which included 3D printed wings, led to conflicting results, however.