Oral presentation- Open Session 12th International Mammalogical Congress

Top-down or bottom-up? Drivers of density and distribution of northern quolls (#258)

Lorna Hernandez-Santin 1 , Anne W. Goldizen 1 , Diana O. Fisher 1
  1. School of Biological Sciences, University of Queensland, St. Lucia, Queensland, Australia

The endangered northern quoll (Dasyurus hallucatus) is a carnivorous marsupial that inhabits the northern third of Australia. It has experienced severe range contraction into rocky habitats and away from lowland habitats. The introduced cane toad (Rhinella marina) is considered a major threat. Being currently free of cane toads, the semi-arid Pilbara region of Western Australia offers a unique opportunity to explore other aspects that may be contributing to the decline of northern quolls. Thus, the main goal of this study was to assess the ecology of northern quolls and investigate drivers of its density and distribution in the Pilbara. We examined top-down and bottom-up processes including predation risk, potential for competition with native species, demography of quolls, habitat structure, den availability, vegetation cover, and prey availability. Our results suggest that prey availability fails to explain range contraction of northern quolls into rocky habitats. Conversely, we found evidence that feral cats (Felis catus) occupy open habitats, excluding quolls form these habitats. Den availability was higher in rocky habitats, offering added protection from introduced predators. The combination of den and prey availability, along with severe droughts, may be limiting factors to quoll density within rocky habitats.