Across northern Australia mammalian diversity and abundance has declined dramatically in recent years. Many mammal species native to Northern Australia now occur only in areas of high topographic complexity and high rainfall such as the north Kimberley. I was interested in why mammal species persist in this region when they have declined so extensively elsewhere in northern Australia. A number of threats are thought to be causing mammalian declines in northern Australia, and our study focused on understanding the impacts of two key threats: changing fire patterns and feral cats. Our results suggest that the topographic complexity and high rainfall in the north Kimberley may support species persistence in the region. Topographically complex areas may buffer resident species from the impacts of frequent intense fires, and feral cats. Occupancy of feral cats was lower in topographically complex landscapes. Also, two mammal species of conservation concern, the golden-backed tree-rat (Mesembriomys macrurus) and the scaly-tailed possum (Wyulda squamicaudata) used fire-sensitive habitats and resources, potentially more available in landscapes where rock features protect them from fire. High rainfall may also support species persistence, as the northern quoll (Dasyurus hallucatus) populations appear to be genetically well connected in such areas. While these features appear to support mammal persistence in the north Kimberley, the decline of mammal species in topographically complex landscapes elsewhere in northern Australia suggests that management of threats including fire and feral cats is required to prevent the loss of multiple mammal species from northern Australia in the near future.
About the speaker
Rosemary is an ecologist and postdoctoral research fellow at Charles Darwin University, studying the response of the Kangaroo Island dunnart (and other threatened mammals) to cat eradication on Kangaroo Island (as part of the National Environmental Science Programme Threatened Species Recovery Hub). She is interested in understanding the drivers of threatened species decline, and spent the last four years examining factors contributing to patterns of mammalian decline and persistence across remote parts of Northern Australia. Since completing her PhD she has worked as an ecologist for Australian Wildlife Conservancy, helping to manage research and contribute to wildlife conservation on their sanctuaries across the Kimberley region of Western Australia.
Short title for tweet: Investigating species persistence in NW Kimberley