See How They Run: Observing Lizards Helps Researchers Aim for Innovation

Through millions of years of evolution, geckos and anoles have developed curved claws and sticky toepads that make them expert climbers.

A team of researchers in the College of Arts and Sciences has been examining how those physical traits could inspire innovations such as new super adhesives and robotic climbing technologies, research that has the potential to not only help humans, but also contribute to the conservation of the lizard species.

Postdoctoral scholar Benjamin Wasiljew and a group of biology student research assistants have been putting a group of anoles and geckos through their paces—having the animals run, jump and climb on various surfaces and at differing inclines.

The group has included doctoral student Aaliyah Roberts ’29;  former research assistant Sierra Weill ’24; former undergraduate student researcher Natalie Robinson ’25; and Maya Philips ’26, who is currently using the research to write her undergraduate thesis.

Foot structure, Tokay gecko (Photo by Austin Garner)

Impressive Climbers

“We are testing their clinging ability on various surfaces and inclines, which helps explain what combination of toepads and claws work best on different surfaces,” Wasiljew says. “We believe adhesive toepads are more effective on smooth surfaces like leaves or glass windows, whereas claws perform better on rough surfaces like tree bark or concrete walls. Anoles and geckos encounter all those types of surfaces depending on whether they live in urban or natural settings. Combining the abilities that both claws and toepads provide is likely what makes geckos and anoles such impressive climbers,” he says.

Benjamin Wasiljew

The research provides a better understanding of how clinging and climbing are handled in nature. Wasiljew believes that knowledge could be used to build physical models based on gecko and anole feet that could lead to new types of climbing equipment, robotic climbing technologies or other innovations.

These new developments could provide better access to hard-to-explore terrains and assist search and rescue efforts when people are trapped in challenging or remote geographic locations or stranded during hurricanes and earthquakes, he says.

Wasiljew and the Garner Lab team work with Syracuse University engineers to discuss ways to implement their biological findings into bio-inspired adhesives and robots. They also collaborate  with biology professor Susan Parks and researchers at her Bioacoustics and Behavioral Ecology Lab. Her group is studying how to build better biologging tags that adhere to the skin of endangered whales to improve tracking and protection.

A Role in Conservation

Understanding how geckos and anoles function in their various habitats is crucial to their conservation, Wasiljew says, because urbanization can threaten their existence. Urban habitats can cause some species to be unfamiliar with how to dwell and move in natural settings that have flexible twigs and branches, versus the concrete and glass materials they encounter in urban areas. Some species don’t adapt well to  habitat changes, which could lead to their eventual extinction, Wasiljew explains. Other species may adapt so well to urban settings that they can come to be regarded as pests.

“Our findings are important because they show how different surfaces affect tree-dwelling lizards and how urban environments can change how lizards behave and how their surroundings can shape their bodies and abilities. It’s research that can both help protect endangered species and limit their negative impacts in urban locations. Understanding how animals respond to human influence or habitat disturbance is crucial to their conservation.”

Jumping Experiments

The researchers discovered that all groups of anoles are negatively affected by having a flexible springboard from which to jump. Urban brown anoles are better jumpers than the naturally-dwelling green anoles and jump further and faster than the brown anole species.

That difference is largest when jumps are made from a stiff springboard and smallest when jumps are made from a very flexible springboard. Surface flexibility affects brown anoles more than the green anoles because the brown urban anoles are more accustomed to the rigid surfaces of urban life than the green species.

From a stiff springboard, brown anoles (like the one pictured) jumped 9 to 10 centimeters further and went 50% faster on average than green anoles. The longer hind legs (averaging 1.5 millimeters more) of brown anoles make them better jumpers. (Photo by Austin Garner)

Watch: Lizards in Action

The first video shows a flexible surface jump of a brown anole. When a highly flexible springboard was used, jump distance and velocity for both brown and green anole species were almost the same.

The second video demonstrates a rigid surface jump of a brown anole. When jumping from a rigid surface, tests showed that brown anoles take off faster but move at a lower angle than green anoles do.

(Videos by Sierra Weill)