London, July 18 - Most lizards are content scurrying in and out of nooks and crannies in walls and between rocks. But neon blue tailed tree lizards (Holaspis guentheri) leap from branch to branch as they scamper through trees in the African forest. A new study has found their bones are full of air to enable them to glide.

Bieke Vanhooydonck from the University of Antwerp and her colleagues, Anthony Herrel and Peter Aerts, decided to find out whether neon blue tailed tree lizards really glide.

they began filming dainty neon blue tailed tree lizards, gliding geckos (Ptychozoon kuhli) and the common wall lizard (Podarcis muralis) as the animals leapt from a two metre high platform to see if the neon blue tailed tree lizards really could glide.

Filming the lizards was extremely difficult. Having startled the small animals into leaping off the platform, the team had little control over the animal's direction, and couldn't guarantee that it was parallel to their camera.

But after weeks of persistence the team finally collected enough film, as the lizards leapt, to compare their performances.

At first, it didn't look as if the African lizard was gliding any better than the common wall lizard. Both animals were able to cover horizontal distances of half a metre after leaping from the platform, while the gliding gecko covered distances greater than one metre, aided by its webbed feet and skin flaps.

But when the team compared the lizards' sizes, they noticed that there was a big difference between the common wall lizard and the tree lizard.