Flying snakes offer lessons to military

Posted by Emma Woollacott

Researchers funded by the Department of Defense have been analyzing the way certain species of snake can glide from tree to tree.

A Virginia Tech team studied Chrysopelea paradisi - one of five species of 'flying' snake - as they launched themselves from a branch at the top of a 15-meter tower.

Flying snakes, they say, show the most complicated glide patterns of any species, thanks to the eleborate undulations of their bodies as they move through the air.

Four cameras recorded the snakes as they glided, allowing Jake Socha and his team to create and analyze 3-D reconstructions of the animals' body positions during flight. These were coupled with an analytical model of gliding dynamics and the forces acting on the snakes' bodies.

The snakes, they found, were able to travel up to 24 meters from the launch platform, but never achieved an 'equilibrium gliding' state - one in which they were able to move at a level height and consistent speed.

Nor, though, did they simply drop to the ground. In fact, the team found that the snakes displayed a 'net positive acceleration in the vertical axis' - or vertical lift.

"The snake is pushed upward - even though it is moving downward - because the upward component of the aerodynamic force is greater than the snake's weight," says Socha. "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."

But the modeling suggests that the effect is only temporary, and eventually the snake is forced to hit the ground.

The military applications are obvious.