Thermal biology, energetics, and torpor in the possums and gliders

Possums and gliders are small, ranging in body mass from about 10 g to about 4-6 kg. All species are largely nocturnal and eat a mixture of food ranging from nectar, pollen, other plant exudates and insects, to leaves and buds. Most possums and glides have a low basal metabolic rate when compared to placental mammals, however, basal metabolic rates of possums and gliders are similar to those of marsupials in general. The thermal conductance of most possums and gliders is also similar to that predicted for mammals of their size. To overcome periods of adverse weather and low food availability, many possums and gliders, especially the smaller species, use huddling extensively. Moreover, some species are capable of undergoing daily bouts of torpor, whereas some of the pygmypossums are capable of deep and prolonged hibernation. While the thermal biology of possums and gliders has received considerable scientific attention, most of the work has been conducted in the laboratory. Thus, more fieldwork is needed to gain a better understanding about the functional requirements of possums and gliders in the wild.