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Silent in flight and endowed with incredibly keen hearing and vision, owls are the stealth bombers of the animal world. So supremely adapted for nighttime hunting are these creatures, tha they make other nocturnal prowlers seem comparatively inept. Unlike those of other birds, the flight feathers of owls are serrated, or fringed, along the forward edge. This softens the sound of their flight, enabling them to swoop in and snatch prey almost before being detected. The rest of the owl's plumage is unusually soft, also serving to cushion the subtle acoustics of flight.
Because owls patrol the same territories night after night, they become intimately familiar with the landscape. In other words, a mouse doesn't have to make much sound or movement to attract owl's attention.
Renowed for their solems, spooky mien, owls have large eyes that face forward, and arrangement that's rare even among predatory birds. This gives them binocular vision and the resultant depth perception necessary to judge distances with almost pipoint accuracy. These fast-focusing eyes are also equipped with a mirrot-like membrane that lets them sample extremely dim light twice, and a dense concentration of light-sensitive cells in the retina. While owls may not be able to see everything in total darkness, they can see what other nocturnal predatos might miss.
An owl's ears (not to be confused with the tufts that are sometimes called ears) are mere holes in the head beneath the fluffy feathers—but what holes they are. Partly because most owls have asymmetrically shaped ear holes, one ear detects a sound ever so slightly before the other one does. This helps the owl to gauge not only the direction, but its distance as well.
Even among owls, the barn owl is a nocturnal wonder, capable of locating prey by sound alone and capturing it in total darkness, though it may be hiding under snow or vegetative cover. The heart-shaped facial ruff that gives this haunting creature such a baleful look also serves to augment its hearing. The concave, stiff-feathered ruff functions as a reflector, funneling sounds toward the ears. The result: a barn owl can locate the source of a sound to within 1.5 degrees of its actual location, both horizontally and vertically—more precisely than any other species of animal ever tested.
Photo credit: R. Straatman © California Academy of Sciences
Source:American Nature, Reader's Digest
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