If I told you that after a recent visit to Tasmania I found the place beautiful, enchanting, magnificent, gorgeous, exceptional and awe-inspiring then I would only have begun the list of applicable superlatives. This large, well-watered island hangs improbably beneath the dry Australian continent to which it bears little resemblance. Because of its abundant rainfall and mountainous terrain, Tasmania is incredibly different from the traditional Aussie outback and looks like a slice of prehistoric New England or northern Europe. If you can imagine that a wild clone of Ireland had somehow been towed down to the southern hemisphere and anchored off the coast of Australia, then you have a feel for “Tassie.” The island is also the unwitting host to a bizarre epizootic that threatens one of the state’s best-known symbols.

Carnivorous Marsupial

Curious and energetic, Tasmanian devils travel long distances each night in their pursuit of food, sometimes covering as much as 16 kilometers.  The mostly black animal is about the size of a modestly sized dog. Males weigh about 15 kg while females are slightly smaller.

The devil, however, makes up for its small size with a well-stocked personal arsenal and a very bad attitude.

The typical devil has very large teeth, jaws as powerful as a crocodile and a well-earned reputation for facing down anything and everything that gets in its way.

Imagine an unearthly, eerie cacophonous choir of terrifying, blood-curdling shouts, screams and groans and you will have an idea of a Tasmanian devil in full throat

As carnivorous marsupials, Tasmanian devils are basically carrion eaters, scavenging anything that comes their way. But they also hunt live prey such as small mammals and birds. Because of their powerful teeth and jaws, devils can eat most of a carcass, including the bones. They are nocturnal hunters, and use their keen senses of smell and hearing to find prey or carrion. By day, they find shelter in caves, bushes, old wombat burrows, or hollow logs. As they amble along with their stocky bodies and large heads, Tasmanian devils may look slow and awkward in their movements, but they are the top carnivore in Tasmania .

The devil is also famous for its vocalizations. Imagine an unearthly, eerie cacophonous choir of terrifying, blood-curdling shouts, screams and groans and you will have an idea of a Tasmanian devil in full throat.

Originally, the devil was found throughout the Australian continent. It, along with the Tasmanian Tiger (another marsupial predator, also known as the thylacine), were at the top of the food chain. However, about 20,000 years ago the Australian aborigines introduced the dingo to Australia . This barkless dog slowly out-competed both the devil and the thylacine. In addition, the aborigines themselves destroyed most of the large Australian prey species that the devil and the thylacine relied upon. As a result of these twin ecological pressures, the devil and the thylacine retreated to Tasmania . There, protected by the rising ocean levels, populations of both species survived into modern times.

The thylacine became extinct in the 1930s while the devil hung on and prospered reaching a population of 150,000 to 200,000 by the mid-1990s.

Epizootic of Facial Tumors Causes Mass Die Off

But with dramatic suddenness and relentless pressure an unusual epizootic (an “epidemic” in animals) of facial tumors has taken hold among Tasmanian devils and threatens to bring the animal to the brink of extinction.

Called devil facial tumor disease (DFTD), the sinister disease manifests itself with an innocuous wound on the snout accompanied by small lesions and lumps similar to those devils inflict on each other when they squabble over carcasses.

This progresses into a bleeding ulcer that typically develops into one or more large and sometimes grotesque tumors. For the next three to five months, the devils go through hell before they die a miserable death from starvation due to large tumor burdens in the jaw and the collapse of bodily functions.  

The first cases were reported in the island’s south and southeast in the mid-1990s but the disease has spread to almost all regions of the island. Official estimates put the number of devils that have fallen victim to this epidemic at about half of the original population.  The disease kills more than 90% of adults in high-density areas and 40-50% in lower density areas. It is now projected that up to 80% of the devil population will be wiped out in the next couple of years.

The disappearance of Tasmanian devils has been noted in unusual ways. Raids on chook houses (henhouses) are down as are reports of devils making dens under homes and tourist shacks. And sightings of untouched roadkill are way up, Tasmanian devils are scavengers--they eat dead animals--and make short work of animals hit by cars.

Cause Remains Elusive

Devil facial tumor disease has resulted in the deaths of 90% of devils in high-density areas

Initially investigators suspected a new form of retrovirus, speculating that the devils were catching the virus from one another during fights over carrion, a common devil behavior.  The yet unidentified retrovirus was believed to initiate a fast-spreading and fatal cancer in the afflicted animal; a fact supported by the fact that all the devils had the same type of tumors. Retroviruses that cause cancers are not unknown; in recent years a number of other cancer-causing viruses have been identified. However, a sudden epidemic or epizootic of such cancer-causing viruses has never before been witnessed in any species.

In mid-April, the Tasmanian Environment Minister Judy Jackson announced that the preliminary results suggested the cause lay elsewhere.  "It's more or less been ruled out that there's a virus causing this tumor and it appears that it is a single-cause cancer tumor that's causing the problem," she said.  While attempts to halt the spread continue, said Jackson, the challenge is daunting. "At the moment we still don't know exactly what it [the cause of the disease] is and, as we know with cancer generally for humans, there's no silver or quick cure."

This may lend credence to arguments by Tasmanian environmentalists that the cause lies elsewhere. Mike Foley of the Far South Wilderness Center- located in the extreme southeast corner of the state, suggests that the government-promoted forestry industry could also be responsible for the outbreak of the disease; as outside the national parks natural bush and old-growth forests are being cleared to make way for tree plantations. The fast growing eucalypt species Blue Gum is commonly planted, which is exported to Asia among others, and is processed mainly into paper. In order to keep the new plantations free of “vermin,” Foley points out, the laying of poison, which ultimately has to end up in the devils' systems by way of the food chain, is practiced on a large scale.

Recipe for Ecological Disaster

Regardless of the cause, the epidemic is interesting from an epidemiological and medical point of view. First, it is taking place in a very unusual species that deserves to be protected both for its rarity and novelty. Fortunately however, this epidemic will not completely annihilate the Tasmanian devil as a species. Contrary to popular myth, natural epidemics are virtually never fatal in species with sufficiently large populations. There are always a few individuals who, by luck or by genetics, survive to carry the species forward. It is expected that such will be the case for Tasmanian devils. To be on the safe side the Australian government is planning, just in case, to have disease-free devil populations established on offshore islands, which are currently free of the disease.

Second, the devil’s decline opens the door for the spread of European red foxes into Tasmania, which could threaten the entire range of less well-known wildlife that has thrived in relative seclusion on the island state.

Foxes have caused environmental destruction on the Australian mainland since their introduction for hunting in the 1850s. It is believed that devils acted as a buffer, stopping them from taking hold in Tasmania. But in 2001 a handful of fox cubs were smuggled into the state then let go for sport. These have multiplied, with the estimated number of foxes now being between 50 and 100. This factor, it is thought, is having an impact on Tasmanian devil population.

The deliberate release of foxes, likened to eco-terrorism by some local environmentalists, has a potential for devastation that compounds the current epizootic and raises the specter of extinction.

The fox threat even has unsentimental Tasmanian farmers on the side of the devil, which they once cursed as a threat to lambs and poultry, and trapped and poisoned, before it was declared a protected species in 1941.  Farmers say they prefer the devil, which has a role in cleaning up the carcasses of dead animals, to the more destructive fox.  

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