PhD Thesis
The northern quoll (Dasyurus hallucatus) is an endangered carnivorous marsupial in the family Dasyuridae that occurs in the northern third of Australia. It has declined throughout its range, especially in open, lowland habitats. This led to the hypothesis that rocky outcrops where it persists provide a safe haven from introduced predators and provide greater microhabitat heterogeneity associated with higher prey availability. Proposed causes of decline include introduced cane toads (Rhinella marina, which are toxic), predation by feral cats (Felis catus), foxes (Vulpes vulpes), and the dingo (Canis lupus), and habitat alteration by changes in fire regimes. The National Recovery Plan highlighted knowledge gaps relevant to the conservation of the northern quoll. These include assembling data on ecology and population status, determining factors in survival, especially introduced predators, selecting areas that can be used as refuges, and identifying and securing key populations. The Pilbara region in Western Australia is a key population currently free of invasive cane toads (a major threat).
The Pilbara is a semi-arid to arid area subject to cyclones between December and March. I selected two sites: Millstream Chichester National Park (2 381 km2) and Indee Station (1 623 km2). These are dominated by spinifex (hummock) grasslands, with rugged rock outcrops, shrublands, riparian areas, and some soft (tussock) grasslands. They are subject to frequent seasonal fires, creating a mosaic of recently burnt and longer unburnt areas. The overall aim of this study was to assess the ecology of the northern quoll in the Pilbara to understand drivers of density and distribution of this endangered species, to enhance species-specific conservation efforts. I collected field data on six one-month trips over three years, predominantly using live-trapping, camera-trapping, sampling invertebrates, vegetation surveys, habitat structure, and den availability surveys.