Complementary lateralisation in the exploratory and predatory behaviour of the common wall lizard (Podarcis muralis)

Abstract

Several ectotherms show lateralisation, particularly visual lateralisation. Such brain specialisation has an ancient origin and is still present in living vertebrates. One important advantage is the possibility for lateralised animals to carry out two tasks at the same time, without altering the efficiency of either one. Recent studies on the common wall lizard (Podarcis muralis) found right eye/left hemisphere bias for attention to the cues of prey, and left eye/right hemisphere bias for controlling antipredatory and exploratory behaviours. However, these studies were independent of each other and therefore were not empirical demonstrations that the directions of visual lateralisation found in this species are present in the same individual, allowing the simultaneous performance of dual tasks. In our study the same Podarcis muralis individuals carried out one exploratory and one predatory test each. We allowed each lizard to move freely in a circular arena, with opaque walls, with either nothing or mealworm larvae in the centre. In the first case the test was an exploratory test, while in the second case it was a predatory one. The results indicated that lizards preferentially used the left eye to observe the environment--i.e., during exploration--and just tended to use the right eye during predation. Hence we conclude that in the Podarcis muralis lizard lateralisation is expressed in the same individual in opposite directions, in accordance with previous observations.

Lateralized Eye Use Towards Video Stimuli in Bearded Dragons (Pogona vitticeps)

“…Most research shows right eye preferences for prey stimuli (Bonati & Csermely, 2011;Robins et al, 2005;Vallortigara et al, 1998). However, the difference in eye use between stationary and moving stimuli suggests that this finding is likely to be an effect of movement.…”

“…Lateralization in eye use has been shown to improve hunting in other lizard species, which predate on similar types of prey (Bonati & Csermely, 2011;Bonati et al, 2008;Robins et al, 2005). Therefore our experiment was designed to investigate (a) whether the response elicited by a female conspecific would be similar to that towards males, as seen in previous research (Hews et al, 2004;Hews & Worthington, 2001), and (b) what level of information is required to elicit any eye preferences.…”

“…Lateralized eye use has been observed in a wide variety of vertebrate species, including mammals (Braccini, Lambeth, Schapiro, & Fitch, 2012;Guo, Meints, Hall, Hall, & Mills, 2009;Racca, Guo, Meints, & Mills, 2012;Smith, Proops, Grounds, Wathan, & McComb, 2016;Versace, Morgante, Pulina, & Vallortigara, 2007), birds (Martinho, Burns, Von Bayern, & Kacelnik, 2014;McKenzie, Andrew, & Jones, 1998;Rogers, 2012;Ventolini et al, 2005;Zucca & Sovrano, 2008), reptiles (Bonati & Csermely, 2011;Hews & Worthington, 2001;Robins, Chen, Beazley, & Dunlop, 2005), amphibians (Vallortigara, Rogers, Bisazza, Lippolis, & Robins, 1998), and fish (Bisazza, De Santi, & Vallortigara, 1999;Bisazza, Facchin, Pignatti, & Vallortigara, 1998;Karenina, Giljov, & Malashichev, 2013). In vertebrates, the right brain hemisphere (which processes information obtained by the left eye) is thought to control emotions and spatial perception, while the left hemisphere (right eye) is responsible for attention, perceptual processing and the control of motor responses (Rogers, Vallortigara, & Andrew, 2013;Vallortigara, Chiandetti, & Sovrano, 2011).…”

“…Various reptile species are known to show considerable lateralization of their behavior (Rogers et al, 2013;Vallortigara & Rogers, 2005), with information about predators and conspecifics being more easily obtained by the left eye (Bonati, Csermely, López, & Martín, 2010;Hews, Castellano, & Hara, 2004;Hews & Worthington, 2001), and information about prey being more easily obtained by the right eye (Bonati & Csermely, 2011;Bonati, Csermely, & Romani, 2008;Bonati, Csermely, & Sovrano, 2013;Robins et al, 2005). These studies exclusively used live stimuli, with restrained male lizards being used to stage conspecific encounters (Hews et al, 2004;Hews & Worthington, 2001), and live mealworms (Tenebrio molitor larvae) used as prey (Bonati & Csermely, 2011;Bonati et al, 2008;Robins et al, 2005).…”

“…These studies exclusively used live stimuli, with restrained male lizards being used to stage conspecific encounters (Hews et al, 2004;Hews & Worthington, 2001), and live mealworms (Tenebrio molitor larvae) used as prey (Bonati & Csermely, 2011;Bonati et al, 2008;Robins et al, 2005).…”