Small mammal species in northern Australia have undergone catastrophic declines, including in key reserves such as Kakadu National Park. The project aims to guide management priorities to recover threatened mammals in monsoonal northern Australia, especially in relation to fire and feral cats. The team is compiling and analysing a large dataset (from Kakadu and comparable other sites in the Top End) on the occurrence of cats, native mammals and fire to evaluate landscape-scale relationships. It is also contributing to the analysis and documentation of responses of native reptiles and mammals to cat-exclusion at established fenced sites in Kakadu National Park.
Small mammal species have undergone catastrophic declines across a broad area of northern Australia, including in many of Australia’s key conservation reserves. This problem of decline has been difficult to resolve because its causes are difficult to pinpoint. Researchers have therefore found it difficult to provide explicit advice about response priorities to managers. This project is addressing this problem by investigating the links between fire management, feral animals, and threatened species in Kakadu National Park and adjacent northern savanna environments.
The research is providing evidence on where feral cats occur across Top End landscapes and the factors that may influence this occurrence. The research team is using existing large datasets to investigate current relationships between mammal diversity, cat and dingo occupancy, fire regimes and habitat characteristics. The data is elucidating the role of cats relative to other potential threats in the observed mammal declines, and assess potential suppressive effects of dingoes on cat.
Although many studies have demonstrated that predation by feral cats and inappropriate fire regimes are likely to be factors contributing to the decline of many mammal species (including threatened species) in northern Australia, it has been difficult to establish landscape-scale responses to these factors, even in conservation reserves. This research is forming part of the evidence base that justifies and helps to effectively target an enhanced management response, particularly by relating cat occupancy to particular fire regimes and/or dingo management, and abundance of native mammal fauna to cat occupancy and fire regimes. This information is helping to assess current fire management initiatives in Kakadu National Park, and to refine future management. It may also help inform the need (or not) for more targeted and effective cat control.
The project is analysing data collected from Kakadu, and other large parks in the Top End (including Nitmiluk, Litchfield, Cobourg and Gregory), the Anindilyakwa, Warddeken and Djelk Indigenous Protected Areas, Tiwi Islands and Fish River Station managed by the Indigenous Land Corporation.
Many small- and medium-sized mammals are in rapid decline in northern Australia with many now restricted to offshore islands. We undertook the most comprehensive assessment of the causes of these declines in the Top End to date. We found that the role of feral herbivores (buffaloes, horses, and cattle) in mammal decline has been underestimated.
Stobo-Wilson, A.M., Stokeld, D., Einoder, L.D., Davies, H.F., Fisher, A., Hill, B.M., Mahney, T., Murphy, B.P., Scroggie, M.P., Stevens, A., Woinarski, J.C.Z., Bawinanga Rangers, Warddeken Rangers & Gillespie, G.R. (2020).
Bottom-up and top-down processes influence contemporary patterns of mammal species richness in Australia's monsoonal tropics. Biological Conservation, Volume 247, 2020, 108638, ISSN 0006-3207. https://doi.org/10.1016/j.biocon.2020.108638.
Stobo‐Wilson AM, Stokeld D, Einoder LD, Davies HF, Fisher A, Hill BM, Mahney T, Murphy BP, Stevens A, Woinarski JCZ, Djelk Rangers, Warddeken Rangers, & Gillespie GR. Habitat structural complexity explains patterns of feral cat and dingo occurrence in monsoonal Australia. Divers Distrib. 2020; 00: 1– 11. https://doi.org/10.1111/ddi.13065
This project is being led by the Northern Territory Government’s Department of Environment and Natural Resources who are working in collaboration with Parks Australia, Anindilyakwa, Tiwi Island, Warddeken and Djelk Traditional Owners and rangers.
Project leaders are NT Government Director of Terrestrial Ecosystems Dr Graeme Gillespie and Charles Darwin University’s Professor John Woinarski.
This project is due for completion in 2020.
Graeme Gillespie, Northern Territory Department of Environment and Natural Resources
John Woinarski, Charles Darwin University