What flies without a wing

As if snakes weren't scary enough if they just crawled on the ground or on branches - some of the reptiles are also able to fly from tree to tree. And without wings.

US scientists have now taken a closer look at how they do it. They will present the results at a meeting of the American Physical Society in Long Beach, California.

The peculiar flying reptiles - five related species of adder in Southeast and South Asia - are something of a biomechanical miracle, said Jake Socha of Virginia Tech in Blacksburg, Virginia. They keep their flat bodies in the air while gliding with undulating movements.

Socha and colleagues filmed Paradise Tree Snakes (Chrysopelea paradisi) on their way down from a 15 meter high tower. The distances they covered were up to 24 meters long.

The biomechanics created 3-D reconstructions of the animals during their gliding flight from the recordings from four cameras. Using a model, they calculated the forces that act on the snakes in the air.

Accordingly, the animals never got into a state of real gliding, in which the forces that their undulating movement cause would constantly counteract the force of gravity. Instead, the reptiles evidently use their entire body in a manner similar to how birds use a flapping wing.

This pushes the snake up again and again, even though it moves down overall, Socha explained. Because the buoyancy generated in this way is greater than the weight of the animal.

"In theory, this means that if the snake continued like this, it could soar," Socha said. But the animals only use the effect temporarily and end up on the ground - or on the lower branches of another tree.

It is left to the imagination of the reader why the research agency Darpa of the US Department of Defense supported the scientists in addition to National Geographic Television.

More information, pictures and videos about the flying snakes can be found here.

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