Last chances: A bold plan to remove all infected Tassie devils is failing, according to a new study.
Credit: Tasmanian Department of Primary Industries and Water
SYDNEY: Culling Tasmanian devils afflicted with an infectious facial cancer – once hoped to be the solution to saving the iconic Australian carnivore – is not slowing the progress of the disease, scientists say.
Capturing and euthanising Tasmanian devils infected with the fatal and disfiguring 'devil facial tumour disease' (DFTD) seems a desperate solution to the epidemic, but new research suggests even this may not be enough.
The Tassie devil population has plunged by more than 50 per cent since the epidemic was first detected, and spreads when animals bite each other around the face and neck while mating and during fights.
Population models
For two years, infected devils have been captured and removed from isolated test populations. Now, an analysis of the results from field trials in the Forestier Peninsula and Fraycinet National Park, both in eastern Tasmania, indicate that an exhaustive program to remove almost every single infected animals would be required to have an impact on the progress of the disease.
"Our most accurate model predicts the need to remove 89 per cent of all infected devils, every three months, just to avoid extinction, and 97 per cent removal to totally eliminate the disease," said Nick Beeton a mathematician who models biological populations.
Beeton, who worked alongside marsupial carnivore expert Hamish McCallum, presented the results of the study today at the Ecological Society of Australia conference held at the University of Sydney. Both experts are based at the University of Tasmania in Hobart.
Losing the game
The study analysed the effect of various disease-fighting strategies on the spread of the disease. Computer models revealed that current efforts are unlikely to succeed without a significant increase in resources and the concurrent use of additional measures.
"Removing devils every three months, as they are [proposing to do] in most of Tasmania, can never succeed," said Beeton. This is because devils contract the cancer long before recognisable symptoms appear.
Menna Jones is a wildlife management officer with the Save The Tasmanian Devil project, co-ordinated by the Tasmanian Department of Primary Industries and Water, and has conducted removal trials in the field. She told Cosmos Online that the exhaustive level of removals predicted by Beeton's model, reflect the results she is seeing in the wild.
"We're slowly losing the game," she said. "This research, and other studies show the current trial is insufficient and removal in the field may not be feasible... additional measures may be needed"
