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Wednesday, 9 January 2008

Lounging lizard

While on the volcanic island of Fogo in Cape Verde recently, I noticed a small lizard that often placed all four feet on its back (see Photo). Why would it do this? It was midday, about 20 °C and in strong sunlight.

Gerben de Jager, Rijswijk, Netherlands

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It has snake envy? :)
By Anonymous Anonymous on January 09, 2008 6:20 PM  
The sun can heat barren volcanic soil as pictured beneath the lizard to very high tempuratures in the zone where Cape Verde lies.

I'd say the lizard's actions are its attempt to prevent its feet from overheating.

Being an ectomorph it's not as easy for it to maintain the temperature of its extremities in a 'safe zone' as it is for mammals.

By lifting its feet off the ground they won't get overheated and possibly suffer damage sufficient to cause the loss of the limb.

This technique does require the lizard's body to be more exposed than it would be lofted off the ground by its feet, BUT even as small as it is, its body is large enough to cope much longer with the extra heat than its feet alone are.

While you didn't say it. I'm sure this pose was just a temporary one, as it moved around hunting for prey or shelter from the sun.

Whenever it felt like its feet were about to fry, it assumed the pose.

Once they cooled down, it resumed its quest.

Its a solution that allows the lizard to survive and exploit a niche it would otherwise not be able to in order to find prey.
We regularly watched little skinks like this 'sunbathing' whilst laying on our balcony sofa when we lived in Seychelles. They found a good, sunny spot, settled down, then raised all four legs behind and above them. In some cases skinks would hang down the front face of the sofa, hooked in by their rear toes and with front legs raised.

Despite being in direct, tropical sunlight, the surface of our sofa definitely didn't hit foot-burning temperatures. So I can only conclude that this position is not, as proposed above, an attempt to avoid burnt toes. I always assumed it was simply a matter of comfort as it seemed to be a favourite position for the skinks to adopt before taking a snooze.
Maybe it's trying to look dead on its back in some kind of antipredator strategy. I'm just guessing...
By Anonymous Anonymous on January 10, 2008 4:16 AM  
Perhaps it is an effort to reduce the total surface area exposed to direct heating from the sun, after the lizard has reached its preferred temperature. The lizard's skin is rather dark and would absorb sunlight well.

Contrary-wise,if the ground is pleasantly warm, perhaps this helps the lizard press more of its body against the ground to absorb the heat.
By Anonymous Barbara Robson on January 10, 2008 4:59 AM  
I have observed my Joburg garden skinks doing the same as described by Steve Copley. They were doing this on the hottest flattest surface available in warm sunlight. I doubt it has anything to do with reducing heat, as the option of shade was nearby.

I noticed that the usually skittish skinks are not easily disturbed from this pose. If prodded they will move off, but will often assume the position again rather than sprint for safety.

My impression at the time was that they were trying to maximize heat absorption, but that doesn't explain the boldness (or was it lethargy?).
Most likely an anti-predator pose used when stationary or basking. Some lizards play dead, some just freeze and others actively defend themselves.

I would doubt that heat was an issue at 20c, however, my observations are Mojave based. Some reptiles here have basking temps of 40-45c.
By Anonymous Anonymous on January 10, 2008 11:54 AM  
I agree with above, it is most likely a posture it takes to give the impression of being deceased. There are a lot of animals which do this while sleeping or basking. Some even go as far as secretion of a scent to mimic rotting flesh.
By Anonymous Anonymous on January 10, 2008 1:43 PM  
The lizard is trying to warm its feet, which would otherwise be shaded beneath their body; the stance may protect against predators as the skink looks dead; it is much safer stance for the animal than trying to roll onto it's side or it's back to warm itself.
By Anonymous greggorino on January 10, 2008 2:54 PM  
Perhaps it does it to appear venomous – like a snake!
Maybe it is dead.
By Anonymous Anonymous on January 10, 2008 5:50 PM  
Easy... Yoga!
By Anonymous Anonymous on January 11, 2008 5:56 PM  
I took a predator's eye view of the picture and it looked pretty much like a stick - with it's legs out it only looks like one thing.....food !
By Anonymous Anonymous on January 11, 2008 6:04 PM  
Even if the immediate environment were not hot, the lizard could be in that pose out of a hard-wired habit to avoid overheating its feet. Rather like chickens that peck all the time even when they "know" there's no food.

Another possibility is that it wants to deliberately heat its feet to rid them of bacteria or parasites.
By Anonymous Anonymous on January 11, 2008 11:13 PM  
To me, it looked, with its feet up, like a snake. Perhaps a way of deterring predators?
Or perhaps it knows something we don't...
By Anonymous The anonymous man on January 12, 2008 2:22 PM  
I believe it is for temperature regulation- I see this pose frequently in basking skinks in Tasmania when the sun has a "bite" but the temperature of the rocks is not particularly warm- in fact they could well be warming the toes up on the body, in my opinion, rather that trying to stop them from getting too hot. I have only ever seen lizards do this in the sun, not on warm rocks in the shade. I have a photograph of a Niveoscincus greeni on Cradle Mountain, Tasmania, in which the lizard has flattened and positioned its body to absorb maximum heat an has its front legs raised over its back. I believe that by pressing the limbs against the warmed skin of the back the lizard raises its temperature more rapidly than by having them splayed over a cold rock in cold air.
By Anonymous Lizardguy on January 13, 2008 11:25 AM  
I seem to recall a kind of desert lizard that stands on 2 legs (diagonally opposed) to keep the other 2 off the ground. How does this compare?
The answer is actually very simple. This lizard is drawn from the genus, loungous lizardous potatae (the common couch potato lizard) and was obviously lacking access to a lay-z-boy recliner and cold beer...
By Anonymous Anonymous on January 14, 2008 1:43 AM  
Its probably just trying to warm its legs, this position is safer than lying on its back because if it did happen to get attcked, it will just have to drop its legs rather than roll over. thats my guess anyway.
I also think the lizard is trying to warm up more quickly. Note that the color of the feet and legs is much darker than the color of its back. Thus, the legs and feet will absorb relatively more sunlight than its back. By wrapping the feet around the back, rather than placing them outward on the ground, the lizard also conserves body heat by skin-to-skin contact. Finally, it does make the lizard look like a stick (when I first glanced at the picture I thought it WAS a stick). So perhaps it's a combination heating/ defense mechanism.
By Anonymous Anonymous on February 07, 2008 7:35 PM  
Could be dead, or posturing (it must be female - only they can touch their elbows behind their back).

But I reckon, as all lizards do, it's just moulting. The rear legs are pushing the skin off. You have all noticed it is trying to look inconspicuous,as one would do when defenceless.

I mean, how long do you spend prone after a skin graft?
You're not the only one with some good news. I've discover a new lizard specie in Angola, it has 2 legs in the back tail. Some people told me that maybe it could be an angolan unique species. People don't even know how to call it. Here's my e-mail; edu_tenente@hotmail.com. Write to me if you want check it, ok? I'll send to you guys the pics and the video.
By Anonymous Anonymous on April 23, 2008 11:40 PM  
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