Sunday 6 April 2014

Burton's Snake Lizard

Image: Matt
Lialis burtonis
What do you think of when you hear the word "gecko"? Feet, yes? Big eyes and big, sticky feet. Spiderman with a tail.

Rules, however, are made to be broken.

Image: Matt
Gekkota is a gigantic infraorder of over 1,000 species of lizard. It contains all the geckos. Of course there are those most gecko of geckos, the fancy-dandy ones with those toe pads that let them walk around on the glass walls of their tank, the walls of your house when they pop in for a visit, or the leaves and branches of trees when they take a holiday in nature.

There are also other Gekkotans who never acquired those magical toe pads or lost them somewhere down the line. Many are ground dwellers, where such things aren't as useful. Some geckos even have round pupils rather than the spooky slits we usually think of.

Image: Mart Moppel
But there is one family within Gekkota that deviates from the gecko template more than any other. It's Pygopodidae, known as Legless Lizards, Snake-lizards or Flap-footed Lizards. Instead of 4 legs like proper geckos, they have 27 legs! I mean, ZERO legs!

Or maybe it's a tiny fraction of legs? The "Flap-footed" name comes from the small flaps that are all that remains of their hind legs. The front ones are gone entirely.

Image: Matt
Like most Gekkotans, Pygopods can't move their eyelids. They have to lick their eyes clean!
As we can see in the amazing success of snakes, a state of limblessness need not dampen the ambitions of a young reptile about town. Indeed, while Pygopods are only found in Australia and New Guinea, they have pretty well conquered that entire corner of the world and made it their own.

And that brings us to Burton's Snake Lizard, the most widespread reptile in all of Australia. They're everywhere! The only part of Australia that hasn't fallen under their domain is the more chilly south eastern parts. To make up for that they have a tiny patch of New Guinea, which I suppose is where they keep their holiday home.

Image: Matt
Beautiful, angry face. Like Jurassic Park's Velociraptors mixed with Baryonyx
Burton's Snake Lizards are tremendously variable in colour, from light and dark greys and browns to stripes or dots and dashes. They're also quite large. A really big one may have a body up to 30 cm (1 foot) long, but the tail is even longer to give a maximum total length of 75 cm (2.5 feet). That would be a female, since they're about a quarter longer than the males.

And, unlike most Pygopods who satisfy themselves on a diet of insects, Burton's Snake Lizards are inveterate carnivores. They're really good at it, too!

Image: JennyKS
With their enormous range, Burton's Snake Lizards have to adapt their behaviour to local conditions. Their main concern is overheating. They can combat a brutal stomping from Australia's feet of heat by being active in the cool night or by staying half buried in leaf litter or foliage.

They don't need to move too much because they're ambush predators. They can just stay put and snatch any lizard who wanders too close. Their favourite food by far is Skink, but they're not averse to other smooth-scaled lizards and snakes. For small prey, a quick lunge and swallow is all that's required. Larger fare requires the use of more tools in the armoury.

Video: skn0904

Burton's Snake Lizards have to be quick and accurate when they strike at larger prey. A lizard doesn't have to be too big before it has enough of a bite to cause real damage, and Snake Lizards have no venom so they can't just bite and put their feet up relax to watch their food collapse in front of them. Burton's Snake Lizards need to aim for the head or neck, bite and maintain a good grip.

The upper jaw contains a flexible joint near the eye which means the entire snout can bend down to completely encircle prey and suffocate them. It also allows for a pretty good impersonation of a sock puppet. A murderous sock puppet with dozens of tiny, sharp teeth, like Chucky on a budget.

Those teeth are hinged so that they fall backward when pushed from the front, but are locked in mean and pointy position when pushed from the back. This allows a big mouthful of lizard to be walked down into a hungry throat with the help of a muscular, decidedly unsnakelike tongue.

Oh, and remember how they have a huge long tail? Well, if the initial strike doesn't work, Burton's Snake Lizards can wriggle their tail in a most appetising manner to lure a hitherto lucky lizard back within range.

Image: Matt
A juvenile. He's so short and stubby!
They can also drop their tail - amputate the thing to distract predators so they can make their escape. It's a less pleasant use for half their body but hopefully it'll make their next meal all the more rewarding.

Of course, the real reward for all this effort, aside from the sheer satisfaction of killing (they look the type), comes in the form of two, leathery eggs usually laid somewhere around November and January. They're left under logs or leaf litter and hatch to reveal youngsters about 13 cm (5 inches) long.

Such fortunate, young lizards. The whole of Australia lies at their feet... er, ventral surface.


Crunchy said...

Pros: we've finally found an animal in Australia that isn't horrifically venomous.

Cons: it's a sock puppet that will bite you until you suffocate.

So, are we calling this a win, or...?

TexWisGirl said...

very interesting species.

Joseph JG said...

@Crunchy: I think we left too many loopholes in the contract. We just can't compete with their lawyers!

@TexWisGirl: It sure is!

Lear's Fool said...

The cute/malicious ratio is all wrong with these guys!

I kinda like it.

Joseph JG said...

There are so many great ways of going wrong!

BK said...

Snake-mimic geckos!

Joseph JG said...

Yes! You'd think they'd value those funky feet a little more!

Unknown said...

those little guys have really evolved from the rest havent they.