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Tassie is facing its greatest menace: if people and foxes have not managed to exterminate the Tasmanian Devil, a contagious facial
cancer could do it, a new epidemic never seen before and against which researchers are desperately looking for a vaccine.
The disease also turns upside down the rhythm of the Tasmanian Devils, the largest carnivore marsupials, after the man-made extermination of the (also) Tasmanian tigers: they mate too early and give birth in the wrong season (winter), when cubs cannot survive. The mysterious cancer was first detected 11 years ago and the strange deadly tumors have killed about half (over 75,000) of the raccoon-sized devils and it is already present in two thirds of the island.
"It is extremely unusual to have this extreme degree of death," explains Nick Mooney, a wildlife biologist with the Tasmanian government.
More worrying, the tumors are contagious: the bad cells can pass from one animal to another, where they grow and eventually dissolve its bones, muscles and tendons like an acid bath.
Some areas have been completely depleted and the island's icon and tourist attraction will become extinct if not protected against the cancer.
"That would be unforgivable," says ecologist Mooney.
The Tasmanian Devil fills a niche similar to that of the hyena in Africa: they devour any corpses (even of other devils), bones included and jaw power is as strong as that of a leopard, the strongest mammals' bite related to their size.
The first Europeans who settled the island in the early 19th century, unprepared for this, were terrified by their nighttime. The Devil has one of the most ghastly vocal repertoires of the animal world, and even worse, it expels a stench stronger than a skunk's one.
"They're sensitive, they're very intelligent and they're cheeky."
The screeching noises are part of a complex threatening behavior, as these lonely carrion-eaters many times feed in teams, eating from large carcasses and kangaroos to cows. They are not social animals and have to keep a pecking order without engaging in dangerous fightings. But it is this behavior of gathering around corpses that turns the Tasmanian Devil vulnerable to cancer.
The malignant cells are transmitted from one animal to another through bites, while feeding or mating (which is not quite tender in this species). This is proven by the fact that most diseased individuals are over three years old, when they reach sexual maturity.
The tumor, known as Devil Facial Tumor Disease, starts its destructive development in the mouth: small lesions on the gums or lips turn into lumps and gaping wounds. The teeth fall out and the tumor develops even through the eyes: the animal's face rots while the it is still alive.
In just a few months, the victims die of starvation as they can no longer bite or swallow.
The cancer is triggered by the cancer cells themselves that are infecting the animals, not by a virus.
All tumor cells displayed very similar genetic material and just 13 chromosomes, or less than healthy cells. The cancer seems to have rooted in a single mutant cell from a source animal, the originator of the epidemic. A similar type of cancer exists in dogs, but in this case, the tumor is relatively benign.
To save the devil, the researchers are trying to understand how the deadly cells circumvent the body's immune defenses, if they can develop a test to detect infected animals before the first lesion appears in the mouth and eventually develop a vaccine.
47 healthy animals have already been put in prolonged quarantine to the mainland, to form an "insurance population." If the disease wipes out the wild Tasmanian Devils, these animals could be used to repopulate their habitats. But, by then, researchers fear that foxes that entered Tasmania by late 1990s could have snatched the Devil's niche.
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