Long-term wildlife disease control and eradication is a major challenge for wildlife conservationists worldwide and has rarely proved successful. It is especially difficult when disease is caused by pathogens able to be transmitted through the environment, such as the sarcoptes scabiei mite that causes sarcoptic mange in bare-nosed wombats (Vombatus ursinus), and which has proved particularly difficult to control in Tasmania’s north-eastern wombat populations. (The Veterinarian November 2016, June 2017).
New research published recently in the Journal of Applied Ecology has identified how lessons learned from a mange treatment program where the disease was temporarily controlled by a Cydectin drench, have been able to guide the development of more effective and feasible controls for the disease.
“The logistics of this treatment made long-term disease control extremely challenging,” explained University of Tasmania’s PhD student Alynn Martin, who was responsible for designing the remotely-delivered treatment using flaps over wombat burrows.
“After three months of trying to treat each wombat in the Narawntapu National Park population every week, the disease returned, and wombats continued to die. It was very disappointing to see after going to so much effort to save these wombats,” she said.
Instead of giving up, researchers used the study to identify practical solutions to the problem and with the help of UTAS ecological modeller Shane Richards, a combination of a longer-lasting treatment, and improved delivery of the treatment, was discovered that allowed wombats to improve their capacity to control the disease within their populations.
“Slight improvements in multiple aspects of disease control can have dramatic impacts on our capacity to control this disease in wombats, and field results suggest the frequency in which wombats change the burrow in which they sleep is an important factor in disease persistence in populations,” Richards said.
A longer-lasting treatment is also in the pipeline, with researchers currently determining its effectiveness. According to Scott Carver, lead researcher and wildlife ecologist at UTAS, the overarching aim is to make the management of the pathogen much more feasible for individual wild wombats and local at-risk populations.