Scientists have for the first time quantified the toll of a deadly facial cancer disease that has decimated the Tasmanian devil population.
From a peak number of about 53,000 in 1996, when the disease was discovered, there are about 17,000 devils remaining, research from the University of Tasmania shows.
“Devil facial tumour disease has caused severe population decline … but previously we didn’t have a good grasp on what factors influenced the spread of the disease or how many devils remained in the wild,” ecologist Calum Cunningham said.
The disease is found in about 90 per cent of Tasmania, and almost all of the devils’ habitat, he said.
“We traced the spread of [the disease] across Tasmania and put numbers on the total size of the devil population, which was a deceptively difficult task,” Dr Cunningham said.
Researchers spent almost 2000 nights trapping devils and analysed “spotlight counts” and trapping records from the past 35 years, to come up with a paper that has been published in Ecology Letters.
The paper includes a prediction that the decline in devil numbers due to the facial cancer will stabilise.
“There are some glimmers of hope and the outlook for devils is better than it was a decade ago,” Dr Cunningham said.
“No monitored populations have gone locally extinct, and our model forecasts the decline should plateau within the next decade at about 12,000 devils.
“These findings suggest the species is at lower risk of imminent extinction than we thought 10 years ago.”