Scientists at Virginia Tech and the University of Virginia are working to uncover this mystery, and determine if the same technology could be applied to robots.
Inside a lab on Virginia Tech’s campus, Jeffery Anderson holds a green and black snake so gently, he’s almost cradling it.
“I grew up watching Animal Planet with my grandfather, and I just loved everything creeping and crawling,” Anderson said.
The snake, a paradise tree snake (Chrysopelea paradisi) is originally from southeast Asia. It's one of the few types of flying snakes on the planet.
Anderson is a phD student at Virginia Tech. He and his mentor, Jake Socha, have been studying why and how these snakes fly.
“So before we started, we have no earthly conception of how this should work,” Socha said. He’s spent the past several years measuring how far they fly. He uses a lift to give the snakes some height, and then watches as they leap for a nearby perch. The higher a snake is, the further they tend to glide.
“The best snake I’ve ever seen was able to go 21 meters (nearly 70 feet),” Socha said. “When that happened everyone was screaming with excitement. And something got into the snake and that snake was just cruising through the air.”
Socha said the snakes aren’t injured by these experiments, as far as they know. What they’ve seen is that the snakes change the shape of their bodies to be more aerodynamic. They actually flatten their bodies, almost like a triangle pancake.
“It sort of wiggles in the air, it looks like it’s swimming in the air. And when you see it, you’re really just kind of blown away,” Socha said. “Because you’re like, a snake should not be moving through the air like this.”
“In the batman movies he can flare out his cape to form a flexible wing,” Anderson adds. “And he catches air. So our snakes are loosely copying that.”
One question they haven’t figured out for sure is why these snakes have evolved to fly in the wild. This is partly because Socha and other researchers have a really tough time trying to track these snakes in the wild.
“It’s been frustrating at times where like you’re inches away from grabbing the snake, and they’re like, ‘I’m out of here.’ And they just jump away and they’re gone. And you never see them again.”
There are a couple of theories about why they fly, either for food, or to find a mate, or to escape a predator. Flying snakes are only known to live in areas of southeast Asia where there are contiguous forests, so there are plenty of opportunities for snakes and other animals to leap from tree to tree. In these areas there are other flying animals, including frogs and squirrels.
Scientists don’t know for sure why only a few species of snakes have evolved to fly.
But now, thanks to a collaboration with an aerodynamics researcher at the University of Virginia, they are starting to better understand how they fly.
“This animal [is] capable [of] generating the same kind of force as an airplane, and can fly in the sky,” said Haibo Dong a professor at UVA. He said technology that adapts the mechanics of flying snakes could be applied to robots. It could be used to assist with search and rescue efforts, like after an earthquake, or another major disaster.
“If they could ever use this gliding, or so-called flying capability, [that] can give them lots of opportunities in the future,” Dong said. “To do the rescue, to search for the survivors. Hopefully we can learn something really useful and improve the quality of our life, the human life.”
In addition to flying, Socha said these snakes also climb and swim. “We don’t have a robot that can do all those things,” Socha said. “But a snake does it, so if we understand how a snake does it, then we can transfer that knowledge toward engineering design and robotics.”
Socha, Dong and other researchers on the team published their findings last year in the journal “Physics of Fluids.” They’ll continue their studies into the mechanics of flying snakes in the next few years.
