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These stealth creatures inhabit various places throughout the world. This Jung Owl lives in the Amazon Basin of Peru. See more pictures of birds.

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How can owls fly silently?

Few creatures are surrounded by as much myth and mystery as the owl. Identified as ominous predictors of death and hardship, they're also steadfast symbols of wisdom and prudence. The owl holds an important place in the folklore of a variety of cultures throughout history. Whether they appear in ancient Greek texts to popular Harry Potter books and movies, owls captivate people by their silent flight. These fascinating animals are capable of some amazing physical feats, such as the ability to fly through the air in virtual silence.

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Many myths developed to explain this mystery. The Greek goddess of wisdom, Athena, has long been associated with the wise and silently flying owl. Preferring this creature as her favorite feathered friend, Athena offered special protection to the owl. As a result, many owls lived in the Acropolis. The stealth-hunting owl also served as a protector to Greek armies. Images of the owl often decorated warriors' shields. Since people believed owls predicted victory when one appeared before battle it signaled triumph. But others saw owls as predictors of death. Legend has it that the hoot of an owl announced the death of Julius Caesar.

What's more, Hindu culture associates the owl and its noiseless flight with the goddess Lakshmi, and considers the owl as a symbol of luck and prosperity. Native American cultures also revere this winged wonder. For instance, Apaches believe that if you dream about an owl, death may be soon to follow. Other tribes, such as the Dakota Hidatsa, view the owl as protectors to warriors. Even today, owls hold a special place in pop culture. How could mail delivery at Hogwarts function without the trusty, noiseless owl postal system?

Let's learn just what's behind the mystery.

Owls' Feathers and Wing Structure

While it adds to the owl's mystique, silent flight serves a very practical purpose. It helps this nocturnal creature sneak up on its prey. But how do owls fly silently in the first place?

While it adds to the owl's mystique, silent flight serves a very practical purpose. It helps this nocturnal creature sneak up on its prey. But how do owls fly silently in the first place?

The design of owls' wings allows them to fly in almost absolute silence. Different parts of their wings and the characteristics of their feathers contribute to their silent flight. Owls have broad wings with large surface areas that help them to float through the air without flapping too much. Less flapping makes less noise.

The main reason owls can fly silently is the uniquely designed leading edges of their primary feathers. When most birds fly, turbulence -- created when air gushes over the surface of their wings -- causes noise. Owls' wings, however, are unique because they reduce noise caused by turbulence.

The main reason owls can fly silently is the uniquely designed leading edges of their primary feathers. When most birds fly, turbulence -- created when air gushes over the surface of their wings -- causes noise. Owls' wings, however, are unique because they reduce noise caused by turbulence.

An owl's primary feathers are serrated like a comb. This design breaks down turbulence into smaller currents called micro-turbulences. Then the edge of the feather muffles the sound of air flowing over the wing and shifts the angle at which air flows. These soft feathers allow air to pass through which eliminates sound. Some people suspect that, as the owls flies, these feathers may also shift sound energy created by the owl's wing to a higher frequency that prey can't hear.

Owls' hertz -- the measure of frequency -- which eliminates all sounds that owls' potential prey can hear [Source: Roach].

So, the secret's in the wings. But does this noise-reducing design have a place in your next airplane flight?

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Using the wise old owl's secret to silent flight may just be the key to reducing airplane noise.

Photo courtesy: NASA

Owl Influence on Aeronautics and Aircraft Design

Engineers constantly search for ways to improve aircraft technology, and nature inspires the greatest innovations. They look to the design of owls' wings to reduce the noise created by aircraft while keeping takeoff energy efficient.

Geoffrey Lilley, a professor emeritus of aeronautics and astronautics at the University of Southampton in England, studies owl flight and the ways it can help aeronautics. Lilley works in conjunction with the Quiet Aircraft Technology project within the Vehicle Systems Program located at NASA's Langley Research Center in Hampton, Va. He and his colleagues are forging the path of owl-influenced aircraft design.

So how can engineers modify an enormous aircraft to mirror the anatomy of the owl? Researchers propose the possibility of creating retractable fringe to mirror owls' trailing feather. For the owl, this fringe reduces turbulence and noise. Some researchers think that applying a velvety coating -- similar to that of an owl -- on landing gear will absorb noise just as it does for the owl [Source: Roach].

Could owls' feathers change your next flight? Airports like Chicago O'Hare and Heathrow have strict noise restrictions on aircrafts take-off. If engineers find a way to reduce noise, more flights can take off every day, and revenue can increase. For an industry struggling with fuel costs and other problems, the wise old owl may provide some solutions.

Lots More Information

Sources

 

 

  • Cornish, Jim. Gander Academy. Owl Myths and Folklore. http://www.cdli.ca/CITE/owl_myths.htm
  • Feathered Facts. Rare Species Conservatory Foundation. July 12, 2008. http://www.rarespecies.org/kids/feath.htm
  • Greeka.com. The Greece Gods of the Mount Olympus in the Greek Mythology. Greece Mythology: A guide to the mythology of Greece and the Greek Island. http://www.greeka.com/greek-mythology.htm
  • Lane, Carolyn and Kennedy, Mike. Lesson -1. Radical Raptors. Raptor Center. College of Veterinary Medicine. Academic Health Center. University of Minnesota. Lesson 1 - Radical Raptors - Raptor Center at the University of Minnesota
  • Lew, Karen. Alaska's Bird of Prey. Division of Wildlife Conservation. Alaska Department of Game and Fish. Teacher Resources. http://www.wildlife.alaska.gov/index.cfm?adfg=birds.raptors
  • North Caroline State University Forestry Extension. Wildlife Publications. Owls (WWW-22). July 10, 2008. http://www.ces.ncsu.edu/nreos/forest/pdf/www/www22.pdf
  • Roach, John. "Owls Silent Flight May Inspire Quiet Aircraft Tech." National Geographic News. December 17, 2004. http://news.nationalgeographic.com/news/2004/12/1217_041217_owl_feathers.html
  • Seife, Charles. "Deathly Hush." NewScientist. March 6, 1999. http://www.newscientist.com/article/mg16121761.100-deathly-hush.html