Are reptiles intelligent? Can they learn? Amazing Reptile Fact 2.

Dr Anna Wilkinson with a bearded dragon. A still from Ingenious Animals
Available on BBC IPlayer till Sept 28 2016.

About 20 years ago I asked a so-called reptile expert whether snakes could think? "No," he replied. "They have a primitive brain."
"How do they find their way about?" I asked him.
"Instinct. Pure instinct." he replied.
Reptiles have a reputation for being stupid animals - " a lower form of life," more "primitive" than mammals, just a bundle of instincts, without feelings, unable to learn.
Wrong.
This slur on reptile intelligence came about for several reasons. One was the rather odd idea we have of the role of intelligence in evolution - a kind of tree of life with clever man right at the top, and all the other animals below, getting stupider the lower they appear. Like an intelligence class system - man as master of the world, animals as peasants or serfs. It's a self-important human idea. Even a mollusc, the octopus, can be pretty bright and may even be able to use tools, something we used to think only humans did. And although reptiles preceded mammals, they have been evolving since then. So even if they started off dumb in the days of the dinosaur (and we have no reason to suppose this) they have been evolving since then.
Work at Lincoln University, under the direction of Dr Anna Wilkinson, has shown that tortoises  can navigate their way through mazes. They can even follow the gaze of a fellow tortoise to find out where it is looking. Lizards can learn whether a food reward is on the left or the right. Tortoises can recognise the difference between a picture of food or the picture of a nonfood object.
Even more extraordinary is that a bearded dragon can learn from watching another bearded dragon tackle a problem. From a video, no less. This was demonstrated in a BBC programme, Ingenious Animals, in which one of Dr Wilkinson's lizards watched a video of another lizard pushing aside a glass door to get at some meal worms. Before he saw the video, he spent a long time trying to learn how to do this. Once he had seen the video, he got the idea far more quickly.
So.... reptiles aren't stupid.

Click here to watch the bearded dragon experiment on BBC until September 28 2016. The bearded dragon part is about two thirds of the way through.

Wilkinson, A.  & Huber, L., (2012), Cold-Blooded Cognition: Reptilian Cognitive Abilities,’ in eds Vonk, J. & Shackleford, T. K. The Oxford Handbook of Comparative Evolutionary Psychology, Oxford, UK, Oxford University Press, 129-143.

Amazing reptile fact 1. Reptiles are cold blooded. Or are they?

Wikipedia

So reptiles are cold blooded. But not always. The Tegu lizard, Salvator merianae, from Argentina warms itself in the sun during spring and summer. At night they retreat to their burrows. In winer (April to September) they hibernate. At the end of hibernation in September the males emerge from their burrows ready to mate.
Their testosterone is high. The muscle in their face, which allows them to bite, swells ready for a fight.  Meanwhile the females are in the borrows, gathering nesting material and laying eggs. She guards them too - a kind of maternal care you see in birds and mammals.
This time of year, the tegus can heat themselves up and keep hotter longer, than would be expected just from basking. Birds and mammals do this all the time, so they don't need to bask in the heat. They make their own warmth.
So why is a reptile, cold-blooded, doing this?  Does this show evolution at work? Is this what was happening when the first mammals or birds emerged from the reptiles?

Read more at Tattersall et al., Seasonal reproductive endothermy in tegu lizards, Science Advances, 2016, 2. 1-7. Found at http://advances.sciencemag.orghttp://advances.sciencemag.org

Sex and the single snake - who needs males?

From Wikipedia

Female reptiles don't always need to mate with males to have offspring. Snakes, Komodo dragons, and lizards have all given birth without sex. These have been females that were kept in zoos, labs or homes, and for some time people thought that parthenogenesis, the scientific name for virgin births, was the just effect of captivity.
But did this happen in the wild? It was difficult to know because some females reptiles can store male sperm for months or years, presumably waiting for a good time to be pregnant, ie a time when there is plenty of food and the right environment. So just because a wild reptile seemed to give birth without mating, it wasn't necessarily so. It was just delayed ordinary conception.
Then scientists, led by Warren Booth, examined 22 litters from broad banded copperhead snakes, A. contortrix,  and 37 litters from pit vipers, A. piscivorus, all from pregnant females collected in the wild. They did a DNA analysis and concluded this was automictic parthenogenesis. This probably means that when the original reproductive cell splits into two, the two new cells merge with each other and then start reproducing themselves (if I understood the process correctly).  The parthenogenesis found in reptiles like a blind snake and some lizards who automatically practice virgin birth is different and I will blog about this later.
This means that if a female snake or lizard cannot find a mate, she can give birth anyway. Aren't reptiles fascinating?  We mammals can't do this!

For more details read: Booth, W., Smith, C., Eskridge, P. H., Hoss, S. K., Mendelson, J. R. & Schuett, G.W., (2012), 'Facultative Parthenogenesis Discovered in Wild Vertebrates', Biology Letters, doi:10.1098/rsbl.2012.0666

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https://www.surveymonkey.co.uk/r/FGJZKLT

The faithful skink - a lizard that practices monogamy.

wikipedia

So called sleepy lizards, the Australian lizards that have large bodies and stubby legs, practice monogamy. When they first meet, they pair up and remain so close together that they are rarely more than 30 centimeters away from each other.
You might think this is just the male's way of keeping a female to himself, and stopping other males mating with her. But he even stays in contact with her after mating though not so closely.
Their pair bonds last better than many human relationships. Scientist spent 31 years studying these animals and found two thirds of them stayed faithful. 31 Partnerships lasted for more than 15 years and, 110 for more than ten years.
So why do they do it? It may be because going steady means a female mate is available, without the male having too much energetic seduction.  She's on tap, so to speak. And the earlier they mate, the better chance they have of having viable babies.
Mind you, not all the females are faithful. About 14% of the offspring are not those of the apparent mate. And it looks as though smaller and less healthy mates are more likely to  be jetisonned by the females.You can read more at

• Leu, S., Burzacott, D., Whiting, M., & Bull, C. (2015). Mate Familiarity Affects Pairing Behaviour in a Long-Term Monogamous Lizard: Evidence from Detailed Bio-Logging and a 31-Year Field Study Ethology DOI: 10.1111/eth.12390

If you have a pet skink, or indeed a pet lizard, snake or tortoise, please do my survey which is here -  https://www.surveymonkey.co.uk/r/FGJZKLT

Why pythons look like boas and boas like pythons.

Black headed python - Wikipedia

It's called convergent evolution.
Different species look alike even though they are not related. Hares and rabbits look alike but they are not the same species. Boas and pythons are another example. They don't even belong to the same family. Yet some of them look just like each other - though their common ancestor was 70 million years ago.
An aquatic python has a head like an aquatic boa and a land dwelling boa has a head like a land dwelling python.  Read more here
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