Energy and Water Metabolism in Free-Living Greater Gliders, Petauroides-Volans

Abstract

Water flux and metabolic rate were measured using a low-level, doubly-labelled water technique in eight free-living greater gliders, Petauroides volans which were maintaining constant body masses at about 1 kg in eucalypt forest near Maryborough, Queensland. Mean water influx was 88.0±3.2 mL d-' and mean metabolic rate was 25.1 L C02 d-' or 520 kJ d-'. These arboreal folivores have field metabolic rates and water influx rates that are 96% and 71% respectively of those predicted for a herbivorous marsupial of their body mass. Assuming that faecal energy losses were 43% of gross energy intakes and that urinary energy losses were 15% of digestible energy intakes, the gross energy intake of the animals was about 1130 kJ d-'. Animals would need to eat between 45 and 50 g of dry matter daily to satisfy these energy requirements. Based on these results, a preliminary energy budget for greater gliders has been proposed.