Imitating the Silent Flight of Owls

Standing on the patio near the bird feeders, I can hear the sound of wings a-fluttering when a customer arrives. It seems that I can even distinguish a couple of different kinds of birds by the sound. If for some reason an owl arrived near the patio, I would not know it.

Credit: Flickr / pics by stefanie (CC BY 2.0)
In fact, I would be mighty startled. Not only are they silent, but many are quite large. Their silent flight has attracted the attention of biomimetics researchers. Their wings and flight have already inspired quieter computer fan blades, and more work is being done for use in flying machines. Of course, some owlhoots give praise to Darwin instead of giving deserved credit to the Master Engineer. Intelligently designing devices based on something they believe happened by chance doesn't make a heap of sense, does it?
If you watch an owl flapping or gliding, it’s like viewing film footage with the sound on ‘mute’—they are so silent. That’s because their wings have velvety surfaces, comb-like serrations (see photo) at the leading edge, and trailing-edge fringes which dramatically suppress the sound of air rushing over the wings. Therefore the owl’s prey (mice and voles) can be taken by surprise.
You can read the rest of this short article by clicking on "As silent as a flying owl".