Fresh thinking on tropical lizards

WHEN IT comes to solving a problem about how to access food, some lizards can more than hold their own.

That's a finding from new research at Duke University which put individual Puerto Rico anoles lizards, Anolis evermanni,(above) to the test.

The setup used a block with two wells in it, one containing food. The trick was to remove a plastic cap from the food-containing well and get the reward that lay beneath.

Some of the lizards solved the problem and removed the cap by biting or bumping it out of the way. In one of a series of tests, the food was switched to the previously empty well and both were capped, but a couple of the reptiles – which were dubbed Plato and Socrates – soon twigged to go for the other cap instead, rather than the previously lucrative one.

"This flexibility was unexpected because lizards are commonly believed to have limited cognitive abilities and highly stereotyped behaviour," write the research's authors in Biology Letters,published online.

McGill University biologist Louis Lefebvre, who was not involved in this study, noted that it could be down to brain size in this species. “We know birds and mammals have bigger brains and that within bird species and within mammal species, the bigger the brain is, the higher the chance of that . . . species making it when moving to a new environment. It may be the same with lizards.”