Lateralization in lizards: evidence of presence in several contexts

Recent research has provided information about the right-eye mediation of predatory tasks in several taxa of ectotherms, while antipredatory and exploratory behaviours are generally mediated by the left eye. This type of visual specialisation allows individuals to hunt and to remain vigilant at the same time. However, very little is known about such specialisation in sauropsids. In this study, we report on several different experiments which have investigated the presence of lateralization in the lacertid Podarcis muralis lizard, for predatory, antipredatory, and exploratory behaviours. We found right-eye control in prey detection in a T-maze and in a detour test. In contrast, in escape behaviour from a simulated predator, we found that lizards significantly preferred to escape to the right, and once at a safe distance, to turn their head back towards the left in order to review the source of the threat, thereby supporting a left-eye mediated processing of antipredatory stimuli. In experiments investigating the exploration of a new environment, a strong left-eye bias was found once again. Finally, with individual lizards tested in experimental situations of both predation and exploration, we confirmed once again a right-eye visual system for controlling predatory cues and a left-eye visual system for controlling exploratory cues, supporting the hypothesis that cerebral specialisation of functions allows the simultaneous performance of important tasks as part of the daily routine.