Seasonal energetics and water turnover of the frillneck lizard, Chlamydosaurus kingii, in the wet-dry tropics of Australia

The field metabolic rates and water fluxes of frillneck lizards, Chlamydosaurus kingii, were studied in the field during three seasons. In the wet season, energy expenditure and water influx rates were relatively high (83.7 kJ kg^-1 day^-1 and 27.5 ml H₂O kg^-1 day^-1, respectively), but they declined substantially during early dry (22.8 kJ kg^-1 day^-1 and 13.6 ml H₂O kg^-1 day^-1 and dry (23.3 kJ kg^-1 day^-1 and 5.6 ml H₂O kg^-1 day^-1 seasons. Dry season values represent a 77% reduction in energy expenditure and an 80% reduction in water flux. During the wet and early dry seasons, the lizards gained small amounts of mass (0.14 and 0.16% mass day^-1), but during the dry season, they lost mass at a rate of 0.06% mass day^-1. During the dry half of the year, the lizards are much less active, and they remain perched in trees. This represents a relatively exposed site for a period of inactivity in a warm climate, but frillneck lizards are nevertheless able to maintain rates of water flux and energy expenditure that are similar to over-wintering lizards and lizards in underground refugia during summer conditions.