November 23, 2010

Researchers Work To Understand Flying Snakes

A researcher at Virginia Tech has been studying an unusual breed of Asian snake that can glide long distances in the air in order to unlock its secrets.

The "flying snakes" of Southeast Asia, India and southern China are able to glide in the air without fixed wings. 

Video of the reptiles show they undulate from side to side to create an aerodynamic system.  It allows the snakes to travel from the top of the biggest trees in the region to a spot about 780 feet away from the tree's trunk.

"Basically they become one long wing," said John Socha, the Virginia Tech researcher who has traveled extensively in Asia to study the snakes and to film them.

"The snake is very active in the air, and you can kind of envision it as having multiple segments that become multiple wings," he told the Washington Post. "The leading edge becomes the trailer, and then the trailer become the leading edge."

The research team set up four cameras and recorded the snakes as they glided.  They then put white dots on the snakes bodies so they could calculate where the animal was in space at each point during flight. 

This allowed the scientists to help create and analyze 3D reconstructions of the animals' body positions during flight.

Socha said the snakes spend most of their lives in the trees.  They are between two and three feet long and about as wide as a finger.  He said the larger snakes generally cannot glide as far as the smaller ones.

The researchers found that the snakes tilt at about 25 degrees relative to the airflow created by their flight, and they hold the front half of their bodies fairly still.

They discovered that some of the snakes can actually turn in the air.  The snakes were able to drop for a while to pick up speed before starting the "air-slithering" movement that helps them stay airborne.

Socha said in a press release: "Hypothetically, this means that if the snake continued on like this, it would eventually be moving upward in the air quite an impressive feat for a snake."

Socha said the snakes are mildly venomous, but "won't hurt a human, though they can be fatal to a gecko."

The National Geographic Society sponsored Socha's initial research, but the Defense Advanced Research Projects Agency (DARPA) funded his most recent work and paper.  Socha said the physical dynamics of snake flight is of great interest to the agency.

Socha's upcoming paper on the dynamics of gliding snakes can be found in the journal Bioinspiration and Biomimetics. 

Chrysopelea paradisi Images Copyright Jake Socha


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