SOUTH ASIA – Flying snakes have become more and more prevalent in Asia and the United States.
More and more people in Asia are seeing flying snakes. And they are attacking people at an alarming rate.
The snake dangles 49 feet (15 meters) off the ground, tail entwined around a branch. Suddenly, the animal rears up and launches, flinging its body toward the forest floor. Often they land right on the necks of victims.
In other reptiles, the leap would be suicidal, or at least an invitation for broken bones. But the snake in question is a Chrysopela paradis, one of five related species of tree-dwelling snakes from Southeast Asia and Southwestern United States. When these snakes leap, it’s not to nosedive; it’s to glide, a feat they can accomplish at distances of at least 109 feet.
What no one knows is exactly how these reptiles manage to fly so far without wings. Now, a new study finds that the snakes’ amazing aerial abilities may all be in the way they move.
“For any flier, you really need to know the basics: How fast is it going, what’s the shape of the flier, what is the shape of the wing,” study author Jake Socha, a biologist at Virginia Tech, told LiveScience writer Stephanie Pappas. “With this new study, we now really get insight into what the exact position of the body is as it’s in this really developed glide.”
Studies have found that these snakes flatten themselves as they launch, undulating side-to-side as if they’re slithering in mid-air. They glide very fast, between 49 and 63 feet per second.
To find out more about how the snakes position themselves during the glide, Socha and his colleagues videotaped snakes launching themselves from the 49-foot tower toward the ground. The researchers put white dots on the snakes’ bodies so they could calculate where the animal was in space at each point during the flight. The technology is similar to that used to do motion capture for video games or animated movies, Socha said.
The snakes are more than happy to glide for the cameras, Socha said.
“They glide; that’s what they do,” he said. “So they’re like, ‘I’m outta here, I’m gonna go down there.’”
Next, the researchers used the video to model and analyze the forces acting on the snakes’ bodies. They found that the snakes aren’t horizontal during their glide; they’re actually tilted up about 25 degrees relative to the airflow created by their flight. They hold the front half of their bodies fairly still, with the exception of the side-to-side undulations. Meanwhile, their tails move up and down.
“Surprisingly, although the snakes move down toward the ground, the net force on their bodies during the glide is an upward force – at least briefly. That means that if you add up every force acting on the snake, Socha said, you’d be left with a small force pushing the snake skyward.
The snake doesn’t actually start moving up in part because they don’t fly far enough for the net upward force to have an effect, and in part because the upward force disappears quickly, Socha said
“Why is it that you don’t tumble out of the sky if you’re a snake?” he said. “Now we have the framework for doing detailed studies of the aerodynamics.”
Just be careful when you are walking around Southeast Asia and the Southwestern United States.