Energy expenditure of the spotted snow skink, Niveoscincus ocellatus, at two climatic extremes of its distribution range.
The study of energy expenditure between populations of a wide ranging ectothermic species may provide an insight into how organisms respond to variation in environmental conditions. In this study, the energy expenditure of male spotted snow skinks, Niveoscincus ocellatus, living at the two extremes of the species' distribution range (warm lowland versus cold alpine site) was measured using the doubly labelled water method. Males at the cold alpine site expended more energy per gram per hour compared to their counterparts living at the warm lowland site. Lizards living at high altitude were active at lower temperatures compared with those at the low altitude site, which resulted in a longer activity time for the highland population. However, the differences in energy expenditure cannot be explained only by these differences in activity time. We further suggest that at the cold alpine site, lizards compensated for the low temperatures by elevating their metabolism which subsequently increased their energy expenditure. An elevated metabolic rate combined with modified thermoregulatory behaviour is likely an important mechanism allowing N. ocellatus to cope with the cold environments at high altitude sites.
School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
Luh P E K
LP
Yuni
School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia.
Susan M
SM
Jones
School of Biological Sciences, University of Tasmania, Private Bag 55, Hobart, Tasmania 7001, Australia. Electronic address: Erik.Wapstra@utas.edu.au.
Erik
E
Wapstra
D000531:Altitude; D000818:Animals; D001481:Basal Metabolism / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology*; D002245:Carbon Dioxide / Q000378:metabolism; D002980:Climate; D003080:Cold Temperature; D004734:Energy Metabolism / Q000502:physiology*; D006702:Homing Behavior; D008116:Lizards / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000502:physiology; D012621:Seasons; D014867:Water / Q000378:metabolism
D014867:Water; D002245:Carbon Dioxide
Activity time; Doubly labelled water; Energy expenditure; Lizards; Metabolism