Thermal ecology of a nocturnal invasive lizard along coastal populations in Northeastern Brazil

Abstract

Temperature is an essential aspect for the whole animal biological functioning, especially for ectotherms, which depend on environmental heat and behavior to adjust their body temperature. In the present study, we evaluated body temperatures of seven urban populations of the nocturnal lizard Hemidactylus mabouia along the northeast Brazilian coast and their relationship with air and substrate temperatures. We found a high overall mean activity body temperature (28.60 ± 1.41ºC), as expected for urban environments, which are generally warmer. Along the seven coastal populations studied here, the mean activity body temperature was related to both air and substrate temperature, reinforcing the importance of the microhabitat to lizard’s thermoregulation. However, body temperature was more strongly related to substrate temperature than air temperature, which is in accordance to thermoregulation by nocturnal thigmothermic lizards. The differences in body temperatures found among some sampled populations may be related to adjustments to each local thermal environment. In this species, males and females tend to operate under similar body temperatures. However, body temperature in juveniles and adults differ in some populations. When we excluded the effect of air temperature and substrate, body temperature does not differ between populations (when São Gonçalo population was excluded), which demonstrates that air and substrate temperatures have a strong influence on the body temperature of these lizards. Descriptive studies that access the body temperature of lizards as the present study are important as a primary data source to monitor the effects of global warming in these animals. Keywords: Thermal ecology, Invasive