Abstract
There has been an alarming and dramatic decline in small to medium sized native mammal species in northern Australia over the past 20 years. The causes of this decline are currently under investigation. There is limited historical and/or current information on health and disease in northern Australian mammal species and it is not known what role disease may be playing in the decline of mammals in northern Australia.
The project objective is to investigate the potential role of disease in the declines of mammal species in northern Australia, focussing on the Top End of the Northern Territory. If species declines continue, then mammal populations will become more isolated; genetic diversity of species will diminish and faunal communities will change. Under these circumstances, the negative impacts of disease will increase. It is therefore vital to understand not only the role that disease may be playing in mammal declines at present, but also to gain understanding of the likely impacts of disease into the future.
The disease investigation project will focus field research efforts on four main sites within the Top End: Kakadu National Park, Bathurst Island, Garig Gunak Barlu National Park on the Cobourg Peninsula and peri-urban areas around Darwin. Other potential study sites include remote islands, west Amhern Land and collaborative northern quail study sites in Kakadu NP. Logistics dictate an initial focus on one species from each major taxonomic group undergoing decline:
Brush-tailed possum (Trichosurus vulpecula); Northern brown bandicoot (Isoodon macrourus); Northern quail (Dasyurus hallucatus ); Brush-tailed rabbit-rat (Conilurus penicillatus).
Golden bandicoots (Isoodon auratus) may be targeted however sample size is likely to be limited. Feral species such as black rats (Rattus rattus) and cats (Felis catus), as well as abundant native species, will also be tested including fresh carcasses. Compromised individuals of any native species will be sampled, including post mortem examination of carcases.
Animals will be trapped during routine fauna surveys and examined and sampled. A wide range of biological samples will be collected (generally under field anaesthesia) and submitted for health and disease screening. This is a strongly collaborative project drawing on support from a wide range of researchers across Australia. Results of the first two surveys (Cobourg Peninsula July 2013 and Bathurst Island September 2013) will be presented.