Shoo them or scare them but there’s no escaping from the creepy crawly lizards. If at times you wonder how despite your best efforts lizards manage to enter into your well-fortified house then you must know that these reptiles are smart enough to adapt to new and ever-changing urban surroundings by learning the tricks necessary to survive.
This is what has been discovered by the researchers after they studied the “survival of the fittest” motto mechanism adopted by lizards, which are closely related to snakes. They found that lizards in the city’s suburbs were street-smart, and learn faster than their rural brethren, to stay safe. The study has been published in the recent edition of international journal Biology Letters.
The study demonstrates for the first time that suburban lizards have faster learning and reversal learning skills for a key survival-related behaviour, finding safety in unpredictable environments.
Anuradha Batabyal and Maria Thaker, both from Indian Institute of Science, probed the learning abilities of the Indian rock agama after capturing a few male species from rural and suburban parts of Bengaluru and placed them in an enclosure with a perch in the middle and two identical refuge spots.
“The refuge spots, made from PVC pipes, were placed at the two farthest ends of the enclosure. In a set of two experiments, they evaluated how quickly the lizards learned to recognise the safety of these refuge spots.
“In the first experiment, one of these spots was regarded as ‘safe’ and marked with a red square. The researchers aimed to teach the lizards that this refuge was safe by gently tapping on the lizard’s tail with a brush to imitate a predatory attack if it chose any other resting spot. Over time, the lizards learned to opt for the safe refuge immediately,” said the study which has appeared in a website, Research Matters.
In the second experiment, the researchers reversed the scenario - the PVC pipe without red square was considered ‘safe’. The researchers imitated predatory attacks on the lizard if it chose this pipe. During the trial, they documented how the lizards had to reverse their previously created associations and learn which refuge was now safe.
The study found that suburban lizards outperformed their rural counterparts in both experimental setups as they were able to identify safe from unsafe refuges rapidly. They did so in just seven trials, while rural lizards needed roughly 14 attempts. This observation suggests cognitive flexibility as the lizards had to unlearn old associations and relearn new ones.
Interestingly, the results of this study were at odds with another one on the garden skinks (Lampropholis delicata) that did not find any differences in learning abilities of the urban and rural populations. The researchers of the current study attribute this difference in learning abilities of lizards to the different selection pressures they face in their urban environments.
The rapid changes that suburban lizards experience within its lifetime play a substantial role in shaping how quickly it learns about safe refuges. The lizard’s increased cognitive ability could be a result of evolutionary differences between the two populations, the individual experiences of a lizard over its lifetime or a combination of both, as per the researchers.
