Energetics and Behavior of Active Subnivean Insectivores Antechinus-Swainsonii and Antechinus-Stuartii (Marsupialia, Dasyuridae) in the Snowy Mountains

Abstract

Antechinus spp. respond to a snow-covered environment by increasing their metabolic rate and by occupying an insulated nest while not active. However, the two species occurring in the Snowy Mountains have different behavioural adaptations: Antechinus swainsonii is diurnal (allowing the benefits of basking in the sun), whereas A. stuartii is nocturnal and makes frequent visits to a communal nest. Antechinus stuartii is able to survive the winter with a lower ratio of field metabolic rate to basal metabolic rate, indicating that it is energetically less stressed and better adapted to existence in the cold per se than is A. swainsonii. However, A. swainsonii appears to forgo the energetic benefits of communal nesting in favour of the lesser competition for food afforded by solitary nesting.