Morphological and physiological determinants of performance and associations to thermoregulatory preferences in an alpine skink, Eulamprus kosciuskoi

Abstract

Performance is dependent on a combination of morphological and physiological features in the context of present environmental factors. Sprint speed is important in the fitness of many animals and is used to represent performance. This study explored the effects of temperature and features of body condition on performance of an Australian alpine skink, Eulamprus kosciuskoi, along with reproductive costs, using sprint speed to represent performance. Further, the effect of size on preferred body temperature was analysed to investigate the determinants of behavioural thermoregulatory responses that are associated with performance. A sample of 21 lizards consisting of juveniles, males and gravid and non-gravid females were caught in December in the Kosciuszko National Park, Australia. Lizards were raced at cold and hot temperature treatments, temperature preference tests were conducted and morphological features measured. Performance was significantly greater at higher temperature and correlated positively with body mass but not with relative tail length. Gravidity incurred no significant performance cost, and no significant correlation was found between preferred body temperature and size. Understanding the determinants of performance, along with temperature regulation effects, has conservation implications in the context of rising temperatures associated with climate change.