Integrating Personality and Thermal Physiology Traits in a Specialist Liolaemus Lizard: Is There a Syndrome?

Abstract

Physiological mechanisms underlie behavioural responses that have important implications for individual fitness. While personality variation is well established in reptiles, the underlying physiological mechanisms are less understood. Studies on lizards have yielded mixed results regarding the relationships between behavioural traits and physiological parameters, with behavioural syndromes, and particularly the connection between personality and physiology, remaining largely unexplored. We assessed the relationship between personality and thermal physiological traits in Liolaemus multimaculatus, considering sex as an intervening factor. Exploration and boldness were compared between familiar and novel substrates, and we assessed correlations with thermal preference and thermal locomotor performance. We found no repeatability in any of the behavioural traits studied, in contrast to thermal preference and thermal locomotor performance parameters, which exhibited high repeatability. Our results do not support the occurrence of a behavioural syndrome, as no correlation was found between boldness and exploration. Exploratory behaviour differed between familiar and novel substrates and sexes, with females being more exploratory than males. More explorative individuals, particularly females, exhibited enhanced performance at lower temperatures, revealing an inverse relationship within the observed thermal-behavioural type. Intersexual differences in lizard behaviour can be attributed to both ecological pressures and physiological mechanisms. Intraspecific variation in thermal-behavioural syndromes can increase a species' niche, potentially favouring its adaptability to environmental change. Previous studies on Liolaemus lizards have independently explored behavioural and physiological responses to environmental pressures. However, a comprehensive understanding of how these traits interact to influence ecological outcomes remains elusive.