The Gecko Tail and Its Feats

A study of the biomechanics of geckos discovered that the animals use their tails for extra control when they slip or fall, helping them steer and move their weight as they climb or even glide.

Biomechanical scientist Robert Full of the University of California–Berkeley, who has studied how geckos get around for more than a decade, had previously conducted experiments to try to determine exactly what role the gecko tail plays. When running on high-traction surfaces, the geckos never used their tails.

But when engineers designed robotic “geckos” to climb walls, they were forced to add tails to keep the machines from tumbling. Full wondered if he had overlooked the role of the gecko tail, and set up experiments to re-examine it.

The team Full led “challenged” geckos with a track designed to make them slip. For instance, the researchers had their gecko examinees run up a vertical track that included a section of slippery whiteboard. ScienceNOW’s Elsa Youngsteadt explains, “When their front feet reached the slick spot, the geckos lost traction and began to tip away from the wall. That’s when the tail took over, making the lizard’s body act like a seesaw anchored at the hind legs.” In other words, as Full put it, the gecko tail is an “emergency fifth leg.”

The team also placed the geckos upside-down on the bottom of a platform that “jiggled like a quaking leaf.” Unsurprisingly, the geckos lost their grip, yet in less than a tenth of a second of falling to the floor, they were universally able to rotate to land on all fours. How? Full says the lizards swept their tails around swiftly to rotate their bodies into “superman” or “skydiving” posture, allowing them to land on all fours. This gave Full’s team yet another idea: were the geckos able to control themselves in the air and “glide”?

Who knew a gecko could someday help us make better robots or maneuver ourselves in outer space?

To answer the new question, the team put the geckos in a vertical wind tunnel. Most animals that can’t fly would have just tumbled around out of control, but the geckos glided neatly, turning and waving their tails to steer and keep themselves upright. Apparently there’s far more to the gecko than meets the eye!

Full says learning more about geckos’ tails may bring improvements to both aircraft and spacesuit design, in addition to helping engineers perfect the gecko-imitating wall robots. Biophysicist Kellar Autumn of Lewis and Clark College, calling the research an interdisciplinary success story, adds, “Who knew a gecko could someday help us make better robots or maneuver ourselves in outer space?”

And of course, while evolutionists have no choice but to chalk this incredible design up to the blind watchmaker of evolution, creationists see that this is just one of the millions of signs of God’s brilliant handiwork in nature.