Returning an extirpated native carnivore to its former range: a habitat suitability analysis of Kangaroo Island for spotted-tailed quolls (Dasyurus maculatus)

Native predators have declined significantly in range and abundance globally. In Australia, the spotted-tailed quoll's (Dasyurus maculatus) range has contracted by up to 30% since Europeans arrived in the late 1700s, with its extirpation from Kangaroo Island sometime after 1837. A feral cat eradication program is currently underway on Kangaroo Island which, if successful, will leave a vacant predator niche. The spotted-tailed quoll has been proposed as the most suitable species to reoccupy this niche, however following its local extirpation, over 50% of the island's vegetation was cleared, mostly during the 1940s-50s, resulting in uncertainty about the current habitat suitability for spotted-tailed quolls. We used MaxEnt and fuzzy modelling to determine if Kangaroo Island in its current state is suitable for reintroduction of the spotted-tailed quoll. MaxEnt modelling suggested that mean annual rainfall and temperature, and soil clay and sand percentage have the greatest influence on habitat suitability. Fuzzy modelling identified distinct patterns of potential den site availability, with > 50% of Kangaroo Island providing habitat containing a suitably large proportion of den sites. Cape Gantheaume, south and south-western Dudley Peninsula and large areas of western Kangaroo Island support the highest habitat suitability and could be suitable initial reintroduction sites.