Archive for » June, 2013 «

Bird-brained or reptile-brained?

Birds and reptiles are commonly held to be lacking in    smarts.   ‘Bird-brained’ was, for instance, often used with reference to the dullness of George Bush – that celebrated blight upon humanity. And a critic who once said, ‘He has the brains of a gecko (Beluwama hoonek ge molayakne thiyanne)’, referring to what lay beneath the presumed shrewdness of Sri Lanka’s first Executive President, certainly wasn’t implying that reptiles were of high intellect. I want to set the reptile intelligence record straight.


Claims that fictional portrayals (such as ‘Jurassic Park’) made for the cunning of prehistoric reptiles may have appeared unrealistic:  dinosaurs turning doorknobs, and the like. But their cousins of today do show remarkable abilities that we tend not to notice. Household geckos, garden lizards and monitors are capable of quite complex mental operations. I was reminded of some sundry observations made over the years whilst reading today that over half of our reptile species will soon be extinct.

Our ubiquitous gecko, I have discovered, is a competent geometrician. To get from a point at the bottom of a wall to one at the top of the wall opposite, it will cleverly follow the shortest line. It plots the correct angle of climb, for a route traversing three walls, despite the three-dimensional projection involved.  More impressive is how it responds when approaches to a window it wants to use to get outside are repeatedly interrupted. At one point it suddenly gives up the effort, goes right out the door opposite – and gets out through the window in the adjacent room. Its purposeful trek suggests a deliberate decision to use the alternative route, outside its present field of vision.


Leave food on a table and the watchful gecko will not make its move from a hidden observation point on the wall until it is satisfied you are not coming back in the next ninety seconds!








The cleverest geckos I’ve met lived in Mount Lavinia.  Right outside our property was a street lamp, which was lit some time between 6.15 and 7.00. Numerous little flying insects that crowded round this lamp provided easy fodder for three or four geckos that spent the night perched strategically on the lamp’s support and the illuminated portion of the post. The geckos did not become prey to birds during daytime because they retired to our roof in the morning, along the wire that fed electricity to the house.




We chanced once to observe, in fading light, our geckos trekking along that wire – to their regular restaurant, for dinner. And they were moving to their post before the lamp had been lit. Instinct could explain their remaining under cover until predatory birds had retired to rest. But to move to their lamp, anticipating it being lit, reflects some fancy learning.

What could have been the cue that told them when to move? Repeated observations showed they moved at around the same clock-time irrespective of ambient light. But the time did change over months, in keeping with the slow shift in time of sunset. I couldn’t work out the solution to this mystery before I moved out of Mount Lavinia.





The geckos around my new abode haven’t yet provided exciting examples, to match these, though monitor lizards have. But monitors aren’t endearing, are they? Obduracy is their thing, and also cunning, more than cleverness.