This project sought to characterise the conservation status of the mammal fauna in northern Australia, investigate factors that may be implicated in the decline of this fauna, and identify effective management responses.
The current rate and severity of decline of the mammal fauna in at least parts of northern Australia is exceptional, with analysis indicating that it exceeds that elsewhere in Australia. This is of considerable conservation concern because northern Australia has previously experienced relatively little loss of biodiversity (since European settlement) and has acted as a refuge for many species and species-groups that have exhibited substantial declines elsewhere in Australia. The current declines in the mammal fauna in northern Australia are also exceptional in a global context, because most declines and extinctions elsewhere in the world have occurred in areas affected by substantial land clearing, habitat modification or hunting, issues that are not (yet) major concerns in northern Australia. A notable feature of the decline of mammals in northern Australia is that declines have been reported from some large and relatively well-resourced conservation reserves, indicating that reservation alone has been insufficient to maintain biodiversity and that the intensity, scope or approach of management in reserves may need substantial refinement.
This project comprised multiple components, including:
Study components demonstrated that predation by feral cats caused local extinction of an experimentally reintroduced population of a native mammal species, and that feral cat impacts were much more severe in areas that had been extensively burnt; but a cat exclosure fencing study in Kakadu failed to demonstrate beneficial response by native mammals, possibly because the study period was too brief and mammal populations in the area were too depleted.
Mammal surveys across combinations of fire and grazing treatments in the Kimberley showed that the benefits of improving fire patterns to mammal richness and abundance were significantly muted if introduced herbivores were present.
The first substantial assessment of the incidence of disease in mammal assemblages of northern Australia indicates the presence of some pathogens that may have lethal or sub-lethal impacts on native mammals, but there is uncertainty around their role in the current decline.
The research took place in Kakadu, Garig Gunak Barlu and Litchfield National Parks, on the Tiwi Islands in the Northern Territory, at Australian Wildlife Conservancy properties in the Kimberley, Northern Territory and Cape York and in the Balangarra Indigenous Protected Area.
Stokeld D, Fisher A, Gentles T, Hill BM, Woinarski JCZ, Young S & Gillespie GR. 2018. Rapid increase of Australian tropical savanna reptile abundance following exclusion of feral cats. Biological Conservation 225: 213-221. https://doi.org/10.1016/j.biocon.2018.06.025.
Conservation Physiology, Milenkaya, O, Weinstein, N, Legge, S, Walters, J, 2013
Ecological Management and Restoration, Woinarski, JCZ, 01/2014
Emu, Woinarski, JCZ, Legge, S, 09/2013
Innovation for 21st Century Conservation, Legge, S, Fleming, A, ISBN: 978-0-9871654-1-1
Austral Ecology, Lindenmayer, D, Gibbons, P, Bourke, M, Dickman, CR, Ferrier, S, Fitzsimons, J, Freudenberger, D, Garnett, S, Groves, C, Hobbs, R, Kingsford, RT, Krebs, C, Legge, S, Lowe, AJ, McLean, R, Possingham, H, Radford, J, Robinson, D, Thomas, D, Varcoe, T, Vardon, M, Wardle, G, Woinarski, J, Zerger, A, 05/2012
Australian Journal of Zoology, Legge, S, Skroblin, A, Lanfear, R, Cockburn, A, 2012
International Journal of Wildland Fire 2012
Conservation Letters, Cawardine, J, O'Connor, T, Legge, S, Mackey, B, Possingham, HP, T.G., M
Biodiversity and Environmental Change: Monitoring, Challenges and Direction , Russell-Smith, J, Edwards, AC, Woinarski, JCZ, Fisher, A, Murphy, BP, Lawes, MJ, Crase, B, ISBN: 9780643108561
Wildlife Disease Association Australasian Section Annual Conference, 29 September - 4 October 2013, Reiss, A, Warren, K, Gillespie, G, Jackson, B, Skerrat, L, Brennan, K, Stokeld, D
PNAS, Woinarski, JCZ, Burbidge, AA, Harrison, PL, 02/2015
Global Ecology and Biogeography, Woinarski, JCZ, 2014
Global Ecology and Biogeography , Fisher, DO, Johnson, CN, Lawes, MJ, Fritz, SA, McCallum, H, Blomberg, SP, VanDerWal, J, Abbott, B, Frank, A, Legge, S, Letnic, M, Thomas, CR, Fisher, A, Gordon, IJ, Kutt, A, 02/2014
The project was led by Dr Graeme Gillespie, with researchers from Charles Darwin University, the Australian Wildlife Conservancy, the Northern Territory Department of Land Resource Management, University of Sydney, the University of Technology Sydney and Murdoch University. The team received valuable assistance from Parks Australia, Kakakadu Traditional Owners, the Tiwi Land Rangers and Balangarra Rangers.
Dr Graeme Gillespie
Department of Land Resource Management
Northern Territory Government
08 8995 5025