Most birds make noise when they fly. Air rushing over the feathers on their wings creates sound, and some birds like doves, for example, make a whistling noise in flight. Others, like swans have heavy bodies and large wing feathers to support the load and they can be heard flying from a distance. But owls need to sneak up on their prey and have developed specialized leading-edge wing feathers with stiff serrations. These serrations break up the air’s noise as it streams over the wings. Then when the air hits the wings’ trailing edge behind the bird, these feathers have a softer, more flexible fringe-like edge that breaks up the noise even more. Many owls have fluffy legs and underparts with downy feathers which then do their part to muffle the rest of the noise. The result? A silent ambush.
Most owls hunt during the quiet and cover of night, and their specialized senses and bodies make it possible for them to locate prey in darkness. They also have the ability to fly silently making it possible to ambush their prey by flying very close to their target to determine exactly where it is, completely unnoticed. How do they do this?
Most birds make noise when they fly. Air rushing over the feathers on their wings creates sound, and some birds like doves, for example, make a whistling noise in flight. Others, like swans have heavy bodies and large wing feathers to support the load and they can be heard flying from a distance. But owls need to sneak up on their prey and have developed specialized leading-edge wing feathers with stiff serrations. These serrations break up the air’s noise as it streams over the wings. Then when the air hits the wings’ trailing edge behind the bird, these feathers have a softer, more flexible fringe-like edge that breaks up the noise even more. Many owls have fluffy legs and underparts with downy feathers which then do their part to muffle the rest of the noise. The result? A silent ambush.
For more information check out this article in NatGeo. Enjoy a comparison between hawks and owls in this video from KQED. And a more in-depth piece from asknature.org.