Thermoregulation across thermal environments in a nocturnal gecko

Abstract

Thermoregulation is a complicated paradigm in ecological physiology, yet is crucial to understanding species' response to climatic change. With an ectotherm's ability to exercise a continuous range of thermoregulatory strategies, describing thermoregulatory behaviour can be complex. The characterization of such behaviour depends critically on measuring the available thermal environment. Here, we examined thermoregulatory behaviour of a nocturnal gecko Gehyra variegata across different thermal environments using the standard index of effectiveness. We measured field body temperatures (T<inf>b</inf>), preferred temperatures determined in the laboratory (T<inf>p</inf>) and environmental (operative) temperatures (T<inf>e</inf>) to compare how closely field body temperatures matched preferred temperatures in comparison with environmental temperatures. We found out that G.variegata largely thermoconforms at night but also shows variation in thermoregulatory behaviour. In particular, there was a significant relationship between the effectiveness of thermoregulation and air temperature, which supports the conclusion that G.variegata can modestly alter their nocturnal thermoregulatory strategy when the costs and benefits change.