Legless lizards are no snakes in the grass, but mistaken identity can get them killed - ABC News
A photo of a slippery-looking character started appearing on Victorian community noticeboards in early December.
Skinny, scaly and emerging as the weather began to heat up, the limbless reptiles bore a striking similarity to something with a far more sinister reputation.
Peter Rowland, author of A Naturalist's Guide to the Reptiles of Australia, says some legless lizards mimic the look and behaviour of venomous baby brown snakes.
"They are not dangerous at all really, apart from the fact that they do in some species resemble juvenile forms of snakes," he said.
"They are actually a type of gecko, and they don't contain any venom at all, but if you don't know what it is then, like any other animal, you should avoid it and give it its own space."
Australia's native snakes are protected but that does not stop them being killed by alarmed campers and property owners. In the process, harmless legless lizards are often innocent victims.
"You're not really supposed to be handling wild animals at all, whether it's a snake or not," Mr Rowland said.
"These won't be giving you a bite, but they might be giving you a fright."
Emerging with warmer weather
Legless lizards usually emerge during the warmer months because they rely on external heat to become active.
During winter months, they go through a period of dormancy. Some bury themselves in the ground while others hide under fallen timber or tin.
When these shelters are removed and the startled reptile attempts to flee, it is hardly surprising they can cause a moment's shock.
For the nature watcher with steady nerves, however, there are some clear differences between a legless lizard and its venomous doppelganger.
Lizards, legless or otherwise, have external ear openings while venomous snakes do not.
And while snakes have the infamous forked tongue used for sensing prey, legless lizards have a fleshy tongue with which they can lick their face and clear their eyes.
A range of subtle differences
Mr Rowland said there were other, more subtle differences.
"You can look at things like the presence or absence of vestigial hind limbs," he said.
"Some species like the scaly-foots have reduced flaps on the back.
"Lizards can lose a tail and regrow a new one but, if they haven't lost the tail, a legless lizard tail is actually quite long when you look at the body shape, whereas snake tails are quite short."
Mr Rowland said the general similarity between legless lizards and the common brown snake was likely caused by what is referred to as convergent evolution.
"They share a similar environment," he said.
"They will hunt within leaf litter and in-and-around rocky escarpments on the surface, so things like forelimbs can get in the way when they're hunting.
"Over the millennia, those limbs have reduced in size and then lost in some species altogether.
"It's more of a hunting or foraging adaptation, rather than losing them so that they can look like snakes."
A spotter's guide
There are about 45 species in Australia, divided into four groups.
They range in size from the very small Delma genus, with adults of some species just 15 centimetres in length, up to more than 60cm for the Burton's legless lizard.
Worm lizards (Aprasia)
This genus includes the mallee worm lizard, the eared worm lizard, and pink-tailed worm lizard.
Appearing more worm-like than snake-like, the mallee worm lizard can be found in far western Victoria and eastern South Australia, while the eared worm lizard is mostly found in the Wathe State Wildlife Reserve.
Slender, and growing to a length of 24cm, worm lizards eat ant eggs and larvae.
Delma lizards (Delma)
Growing to 30cm, members of this genus are most often mistaken for brown snakes.
Species found in Victoria and southern New South Wales include the marble-faced Delma, spinifex Delma and the endangered striped Delma.
Most of the body length is tail and they feed on caterpillars, insects and spiders.
Burton's legless lizards (Lialis)
Also called flap-footed lizards or snake lizards, Lialis lizards are found throughout Australia, except for southern Victoria and Tasmania.
They have a distinctive elongated snout and feed on other lizards, including skinks and other legless lizards.
Scaly-foot lizards (Pygopus)
These are among the largest legless lizards in Australia and grow to about 50cm long.
Their colours range from grey to copper and they are often mistaken for a small snake.
Scaly-foot lizards can be kept as a pet in Australia with an appropriate licence.
They feed on spiders and insects in the wild but will eat fruit in captivity.
An evolutionary advantage?
Mr Rowland said there could be evolutionary advantages to looking like one of the most venomous creatures in the world.
"Having the appearance of something that's bit more fierce or something that can poison you, a predator is likely to give you a bit of a wider berth than something that's more appetising to look at," Mr Rowland said.
"By the same token, the majority of these lizards are cryptic in colour and pattern, so that they can blend in with their surroundings.
"It's a double-edged thing."
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