No behavioral syndromes or sex‐specific personality differences in the southern rainforest sunskink (Lampropholis similis)

Abstract

Behavioral syndromes, when individuals within a population express consistent behavioral differences across time and context, are widespread in animal taxa. For many species, males and females experience different selective pressures after maturation, resulting in the divergence of life‐history and behavioral traits. However, the potential for sex‐specific differences in individual behaviors and behavioral syndromes has rarely been assessed. Here, we tested for sex‐specific differences in behavior (activity, exploration, sociability) and personality in the southern rainforest sunskink, Lampropholis similis. We found that most behaviors in L. similis did not differ between sexes, the exception being sociality which was higher in females than males. In terms of consistency among behaviors, activity and exploration, but not sociability, were repeatable, and there were no sex‐specific differences in repeatability of behavioral traits. Although a behavioral syndrome among these three traits is present in a congener (L. delicata), we found no evidence for such a syndrome in either sex of L. similis. Our study is consistent with the results of studies on other Lampropholis skinks that have found only limited sexual differences in behavior. More broadly, our study demonstrates there can be considerable differences in the presence or absence of behavioral syndromes in closely related species.

Effects of developmental environment on animal personality in a tropical skink

“…Overall, differences in repeatability because of variation in developmental environment were primarily driven by changes in within-individual variation, which were higher in a greater number of traits for the high incubation treatment and lowest in the wild-caught group. We also found no evidence for a behavioral syndrome involving these behaviors in rainforest sunskinks, similar to previous studies on this species (Goulet et al 2021), indicating that incubation temperature, as well as rearing in a captive compared to wild environment, does not affect between-individual correlations among behavioral traits. While our results further highlight the lasting effects of developmental conditions on an organism's phenotype via behavioral responses, the fitness and ecological consequences of these effects remain unclear.…”

“…In this species, incubation temperature was found to affect dessication rate and short-term critical thermal minima (Llewelyn et al 2018), but effects of incubation temperature on behavior have not yet been investigated. Furthermore, while no behavioral syndrome has yet been found in captive-reared southern rainforest sunskinks (Goulet et al 2021), previous studies have suggested that natural environments may be necessary to generate and maintain repeatability in, and correlations between, behavioral traits (Wilson et al 1994;Urszan et al 2015). As such, a secondary aim of our study was to investigate if skinks that had developed in captivity differed in animal personality from those that had developed in the wild.…”

“…These effects may be driven by different costs of development (Marshall et al 2020) or expression of hormones, such as in leopard geckos, Eublepharis macularius (Rhen et al 2005), which can then affect phenotypic plasticity (Dufty et al 2002). Lizards from the Lampropholis genus are regularly used in studies investigating animal personality (e.g., Michelangeli et al 2016aMichelangeli et al , 2018Goulet et al 2021) as well as effects of incubation temperature on physiology and behavior (e.g., Downes and Shine 1999;Llewelyn et al 2018;Kar et al 2022). Accordingly, we used a species of Lampropholis skink to investigate the impacts of incubation temperature on animal personality.…”

“…We then examined whether there were any differences in the same behavioral measures between the behavior of both incubation temperature groups to that of their fathers, who had been captured from a wild population. We focused on only males, and hence fathers rather than mothers, as there is evidence for limited sex-specific personality in Lampropholis skinks (Michelangeli et al 2016a;Goulet et al 2021), as well as to exclude reproductive state as a confounding factor. Repeatability was expected to be higher in the wild-reared skinks, which may be due to past exposure to factors such as predation, as in agile frog tadpoles (Urszan et al 2015), or due to greater varation in natural environments allowing populations to express greater between-individual variation (Bell et al 2009).…”

Sex-specific behavioral syndromes allow the independent evolution of behavioral dimorphism

“…More recently several studies have also compared syndrome structure among sexes with mixed results. Some studies reported large differences in behavioral syndromes between males and females (Fresneau et al 2014;Han et al 2015;Way et al 2015) while others support a conserved syndrome structure between sexes (Michelangeli et al 2016;Goulet et al 2021). Our results supply an additional line of evidence in favor of sex-specific syndromes.…”