Water and Energy Turnover in a Small Monitor Lizard, Varanus-Acanthurus

Abstract

The field metabolic rates and water influxes of Varanus acanthurus were determined by means of doubly-labelled water during late spring. The mean metabolic rate was 0.101 +/- 0.032 mL CO2 g-1 h-1, which was equivalent to an energy expenditure of 63 kJ kg-1 day-1 and a fresh food consumption rate of 13.2 g kg-1 day-1. The mean rate of water influx was 15.9 +/- 6.8 mL kg-1 day-1 and it is suggested that up to 30% of water influxes are via pulmo-cutaneous exchange and drinking. It is considered that V. acanthurus is a secretive 'sit and wait' predator and that this accounts for the lower than predicted water influx and metabolic rates of this species.