Prey quantity discrimination and social experience affect foraging decisions of rock lizards

Abstract

Animals often face situations that require quantity discrimination for decision-making. Differentiating between more and less amounts might be adaptative in different contexts such as in social relationships, navigation, or foraging. However, feeding close to conspecifics might change foraging behavior decisions due to changes in predation risk perception and competition for resources. Here, we tested the quantity judgment abilities of foraging rock lizards (Iberolacerta cyreni) in a spontaneous choice test between 5 and 10 cricket prey. Lizards tested had been previously housed alone or in a group to examine how social experience affected foraging decisions. Our results showed that “grouped” lizards had greater foraging activity than “solitary” lizards. Furthermore, all lizards demonstrated some ability to discriminate between the two amounts of prey. These results reveal the capability of quantity judgments in rock lizards and also that foraging decisions may be modulated by the previous social experience. The presence of food sources differing in quantity, together with the proximity of conspecifics, can strongly affect foraging decisions. Previous studies showed various levels of quantitative abilities on different taxa, but results with reptiles are scarce and inconsistent. On the other hand, previous research showed that grouping may have a notable effect on foraging behavior. Here, we demonstrate that male rock lizards can discriminate between two amounts of prey and that there is an effect of the previous social experience on foraging behavior, as lizards that had been housed alone showed less interactivity with food. These outcomes reveal the existence of quantitative abilities in lizards and the importance of the previous social experience in foraging decisions.