Australia’s legless geckoes
Everything that slithers is not a snake.
Tim Low lives in a state of perpetual surprise at everything wild and alive. His response is to write searching books, Australian Geographic articles and this blog. His book Where Song Began (Penguin, 2014) recently became the first nature book ever to win the Australian Book Industry Award for best general non-fiction. Tim’s newest book is called The New Nature.
AFTER A MEAL it licks its eyes. It has a hinged head and little flaps instead of feet. This is Burton’s legless lizard, an animal worth getting to know.
My first childhood encounter with one was both thrilling and disappointing. In a small pocket of bush near my grandmother’s house I was excited to have seen my first wild snake, but there was none of the liquid motion I had expected. What fled from me was clumsy in its haste, and looked ridiculous, with a pointy snout on a short thick body. It was a caricature of a snake.
I later realised I had seen a legless lizard, a member of a family special to Australia and New Guinea. Burton’s stands apart from most legless lizards by operating, like a death adder, as a sit-and-wait predator. Hiding in leaf litter, possibly for days at a time, it lunges at passing lizards. It can wiggle its tail as a worm-like lure. Speed and grace are not necessary for this ‘lazy’ lifestyle.
A serious predator, a Burton’s can gulp down lizards as thick as itself. Small snakes are eaten as well. It has a hinged head so its snout can flex down at a 40 degree angle to maximise tooth grip on large prey. The long hinged teeth can be folded out of the way when not in use.
Here, you can see the immense variation in colour patterns. (Image Credit: Matt Clancy)
What is surprising about legless lizards is evidence showing them to be specialised geckoes. Like typical geckoes they make sounds and lick their faces to remove dust, and they have internal features that conform as well. As for the flaps, these are vestiges of the hind legs of their forebears. A 2004 DNA study found that leaf-tailed and knob-tail geckoes are much more closely related to legless lizards than to most geckoes.
But how would evolution help a gecko by disposing of its legs? There must have been a species that, by hunting spiders down burrows, became slender and ultimately snake-like.
Legless lizards deserve our appreciation, but their image suffers for lack of a consistent common name. Some experts like to call them ‘flap-footed lizards’ and others ‘snake-lizards’. The ideal name in my view is ‘legless geckoes’. In a recent scientific paper they are ‘slithering geckoes’. Long may these geckoes slither.