Researchers have filmed geckos trying to run up walls and taking tumbles when the going gets too tough for their sticky feet. The resulting videos show the ninja-style tail-flipping actions used by the geckos to stay in place or land the right way up (paper; press release; sample news story on BBC; videos by New Scientist on YouTube).

The researchers first report on just how a gecko manages to stay on track when climbing a vertical surface and its front feet hit a slippery patch. The answer? It braces itself with its long tail. As its front hands go flying off – an action that would peel a human climber off her perch – a gecko uses its tails to lever the top half of its body back towards the wall (see pic below). Not such a surprising result, really, but the videos are good fun to watch (YouTube). The researchers say they’ll be using the results to help better design wall-climbing robots (though I can’t help thinking that a wall-climbing robot would do better if it’s ‘tail’ also had feet… ie if it was just a long, flexible millipede).

The more beautiful still photos (see top snap) show how a gecko rights itself when free-falling towards the ground. Cats twist their bodies to ensure that they land on their feet; geckos instead use their tails to whip their bodies around. The freeze-frame still photos of this action (see below) are not wholly illuminating to the casual observer (I can’t really tell what the tail is doing by looking at these snaps alone, though I’m happy to believe the researchers can). But they look darn cool nonetheless.

Top picture credit Robert Full/UC Berkeley, copyright PNAS/NAS 2008

Images courtesy of National Academy of Sciences, PNAS (Copyright 2008).