Watch: a gecko runs on water
Reptile strategy could inspire swimming robot design. Nick Carne reports.
This video illustrates a lovely example of making the best of what nature gave you.
The flat-tailed house gecko (Hemidactylus platyurus) is too small to walk on water but too big to take advantage of the surface tension and just float, so it does a bit of both.
And the result, British researchers have discovered, is a not too shabby speed of almost a metre a second.
In a paper published in the journal Current Biology, they reveal that the mouse-sized lizards move over water using a unique mix of gliding and foot slapping – striking the surface with enough force and speed to keep from sinking.
The scientists, led by biophysicist Jasmine Nirody, from the University of Oxford, saw that a gecko’s legs slap and stroke the water surface, creating air pockets that keep most of its body afloat. It then trots across the water much as it does on land.
Its water-repellent skin also helps it skim over the surface, while its swishing tail stabilises and propels it forward.
“Even knowing the extensive list of locomotive capabilities that geckos have in their arsenal, we were still very surprised at the speed at which they could dart across the water's surface,” says Nirody.
“The way that they combine several modalities to perform this feat is really remarkable.”
And possibly instructive. Nirody suggests the gecko’s “multi-modal locomotive strategy” could inspire the design of swimming robots for search and rescue in flooded areas.