The Subalpine Climate at Smiggin Holes, Kosciusko National Park, Australia, and Its Influence on the Biology of Small Mammals

Abstract

Three species of small mammals, Mastacomys fuscus and Rattus fuscipes (both rodents), and Antechinus swainsonii (a small dasyrurid marsupial) live in the subalpine heathlands of southeastern Australia. This study records the climate and microclimate of these heathlands. Temperature was recorded at three sites at Smiggin Holes in Kosciusko National Park--just above the shrub layer, in a runway, and 20 cm below ground. Long-term meteorological data for ambient temperature, rainfall, and thickness and duration of snowpack are also presented. In summer, these small mammals experience temperatures of +5 to + 100C while active and foraging at night, and temperatures of about + 100C in burrows during the day. In winter, the snowpack provides good insulation resulting in a constant temperature of 0 to - IoC in both runways and burrows regardless of the ambient air temperature above the snow. The climate and microclimate in the Australian Alps has many influences on the biology of small mammals; these include a short reproductive season, delay in the time to maturity and initiation of reproduction, reduced activity or torpor in winter, and relatively stable interannual population numbers.