Wings Designed With Silencers

The feathers of most birds make noise as they whir through the air in flight. Not so with owl feathers; they are specially designed for silence. They are soft and downy, with a velvety feel, so wind makes no noise as it passes over them. The flight feathers do not have straight, hard edges like those of most birds, which produce a whirring noise as they fan the air in flight. The barbs on the owl’s feathers are uneven in length, leaving soft fringed edges that make no sound as they sweep through the air.

World Book’s Science Year 1983 explains: “The barn owl’s great sensitivity to sound is largely due to the sound-collecting property of the facial ruff​—the wall of stiff, densely packed feathers that makes a heart-shaped outline around the face. . . . Like a hand cupped behind an ear, the large surface of the ruff collects sound and channels it into the ear openings.”