A fatal and grotesque facial cancer is decimating the Tasmanian devil population.
For the last ten years the facial cancer has contributed to the deaths of up to eighty per cent of infected devils. The animals develop facial tumours that prevent them from feeding properly. They become emaciated, usually dying within six months.
The Tasmanian devil, Sarcophilus harrisii, is the largest surviving carnivorous marsupial and usually lives to the age of around five years. Hunted to extinction on the Australian mainland, the Tasmanian devil is now only found in Tasmania.
Scientists, many from Tasmania's Department of Primary Industries, Water, and Environment (DPIWE), are studying the animals to try and understand the disease but also to try and find ways to save the threatened population before it is too late.
Biologist Anne-Maree Pearse found that the cancerous cells from infected animals seem to have identical abnormal chromosomes. This could mean the disease originally came from one individual. This idea seems possible as devils have a low genetic diversity due to the small numbers of animals in the wild - lack of genetic diversity can hamper the animal's immune response making it more susceptible to infections or cancerous cells transmitted when the animals bite each other during mating battles.
The discovery of three partly resistant individuals is encouraging. These animals have tumours but have survived much longer than expected so could be extremely important in developing a vaccine.
Another avenue for investigation is whether removing infected animals from the population helps to prevent the cancer spreading. So far, a trial in an area that is separated from the Tasmanian mainland by a bridge, proved successful at first but later failed because devils managed to swim across the small canal.
Another twist in this tail is that devils living in western Tasmania seem to be genetically distinct from the eastern population. Scientists are studying the animal genes to look for any genetic variation between the groups that may be responsible for this resistance.
These different scientific approaches, including looking at captive breeding programmes and even saving tissue samples for possible cloning in future, mean there is still hope that the Tasmanian devil population will be able to recover from this terrible disease.
The research is published in the journal Nature .
A new book, Tasmanian Devil: A Unique and Threatened Animal , looks at the impact the disease is having on the long-term survival of the devils.
The book reveals the true nature of the Tasmanian devil - far from being a scavenging, ferocious oddity, it is a treasured and valuable wildlife species, and one that needs protection.
Tasmanian Devil: A Unique and Threatened Animal is written by David Owen and David Pemberton, published by the Natural History Museum, can be bought from the online bookshop.