Sprint speed capacity of two alpine skink species, Eulamprus kosciuskoi and Pseudemoia entrecasteauxii

Abstract

As global average temperatures continue to rise as a result of climate change, it is increasingly important to understand how some of the most vulnerable environments may be affected. The alpine environment and specialised biota of the Kosciuszko National Park are strongly influenced by abiotic factors such as temperature. Lizard performance in particular is closely related to temperature change. This study looks at the sprint speed capacity of two alpine skink species, Eulamprus kosciuskoi and Pseudemoia entrecasteauxii, as an indicator of fitness. Lizards were collected from two sites at Rainbow Lake and Charlotte Creek. These were raced over a 1 m distance and their sprint speeds were recorded at 25 cm intervals. Trials were conducted at room and elevated temperatures, and sprint times were compared between trials, species and sex and, for females, between gravid and non-gravid individuals. It was found that fitness, as measured through sprint speed, was greater at an elevated temperature for both species, and that E. kosciuskoi were significantly faster than P. entrecasteauxii. No significant differences were found between sexes or gravid and non-gravid individuals. It is possible that the lizard species studied would benefit from increased sprint performance linked to increased average temperatures; however, if temperatures rise above the skinks’ physiological optima, it may have an extremely detrimental effect on all aspects of the lizards’ biology.