Sociality in lizards: Why do thick-tailed geckos (Nephrurus milii) aggregate?

Abstract

Unusually among lizards, Australian thick-tailed geckos (Nephrurus milii) aggregate in their diurnal retreat-sites. They continue to do this in the laboratory, even when excess shelters are available. We manipulated cues available to captive lizards to investigate three putative advantages to aggregation: enhanced social interactions, avoidance of predators, and control over rates of heat or water flux. Trials in which we prevented physical contact with conspecifics eliminated the aggregative response, suggesting that chemical and visual cues alone do not stimulate aggregation. Adding the scent of a predatory snake did not modify the degree of aggregation, nor did changes in mean ambient tem..