Oral Presentation- Symposium 12th International Mammalogical Congress

Vegetation dynamics at refuge sites of the plains mouse (Pseudomys australis) in the western Simpson Desert, Australia (#199)

Catherine E M Nano 1 , Chris R Pavey 2
  1. Northern Territory Government, Alice Springs, Northern Territory, Australia
  2. CSIRO, Alice Springs, NT, Australia

A diversity of rodents and dasyurid marsupials in arid Australia occupy refuges; discrete areas of the landscape in which populations persist during periods of low resource availability (‘busts’). Refuges are assumed to provide shelter from predators, suitable microclimate for thermoregulation and food resources during the low phase of population cycles. During bust periods, refuge-using small mammal populations occur at high density in refuges and individuals are in a body condition that is comparable to that of individuals during population irruptions. Reproduction is also ongoing. These findings imply that refuge populations of small mammals have access to a reliable and high-quality food supply. We examine this issue by quantifying the vegetation dynamics at refuges of the plains mouse (Pseudomys australis) on cracking clay and gibber plains in the western Simpson Desert. In particular we focus on changes in richness and abundance of plants across the population cycle of refuge populations of P. australis. Refuges typically occur in areas of microrelief within the landscape. Vegetation responses in these areas are driven by rainfall. Shallow-rooted, short-lived grasses and forbs dominate the flora. These plants have the capacity to respond to small rainfall events that occur during dry periods. Among these are important food plants of P. australis including Dactyloctenium radulans, Chloris pectinata and Panicum sp.. Thus, the location of P. australis refuges in areas of microrelief is likely to ensure access to suitable food plants even during dry years with some food available in some patches at most times.