CANBERRA, Australia — "The Tasmanian devil, a snarling fox-sized marsupial made notorious by its Looney Tunes cartoon namesake Taz, was listed in Australia as an endangered species Friday because of a contagious cancer that has wiped out most of the wild population.
The upgrade from "vulnerable" under Australian environmental law entitles the world's largest marsupial carnivore to greater protection in the island state of Tasmania, Environment Minister Peter Garrett said in a statement."
"Devils do not exist in the wild outside Tasmania, although mainland zoos are breeding captive populations as a strategy against total extinction."
"Strong action is being taken to find out more about this disease and to stop its spread," Garrett said.
"These mammals have a squat and thick build, with a large head and a tail which is about half its body length. The devil stores body fat in its tail, so unhealthy devils often have thin tails. Unusually for a marsupial, its forelegs are slightly longer than its hind legs. Devils can run up to 13 km (8.1 mi) per hour for short distances. The fur is usually black, although irregular white patches on the chest and rump are common. Males are usually larger than females, having an average head and body length of 652 mm (25.7 in), with a 258 mm (10.2 in) tail, and an average weight of 8 kg (18 lb). Females have an average head and body length of 570 mm (22 in), with a 244 mm (9.6 in) tail, and an average weight of 6 kg (13 lb). This correlates to an animal which is the size of a small dog."
"The average life expectancy of a Tasmanian Devil in the wild is estimated at six years, although they may live longer in captivity. The devil has long whiskers on its face and in clumps on the top of the head. These help the devil locate prey when foraging in the dark, and aid in detecting when other devils are close during feeding. When agitated, the devil can produce a strong odour, its pungency rivaling even the skunk."
Sadly, Tasmanian devils are threatened by a facial cancer which spreads from devil to devil by their habit of biting each other.This results in an affected devil's face being covered with tumors
Scientists have long known the disease is infectious, but nobody understood what caused it. Some suspected that it might be transmitted via a virus.
But Anne-Maree Pearse, a biologist at Tasmania's Department of Primary Industries, Water, and Environment, thought something more exotic might be at work.
Now she and coworker Kate Swift believe they've found the answer: The animals inject cancer cells into each other when they engage in mating battles. When a cancerous animal bites a healthy one, Pearse reported this month of the journal Nature, cancer cells can break off the cancerous devil's face. Some of these cancer cells are then implanted into the bite wound. There they thrive, growing into new tumors. It's a process similar to that by which human tumors multiply within a single individual: by shedding cells that move through the bloodstream.
The idea that something like this could be happening via bites, however, is new.
The smoking gun lies in the tumor cells' chromosomes, structures that contain DNA.
Tasmanian devils normally have 14 chromosomes. But the cancer cells contain only thirteen. And those 13 are "grossly abnormal," Pearse wrote in the new study.
More important, she found that the abnormalities were identical in 11 sick animals collected from widely separated regions.he tumor cells' chromosomes are so similar, Pearse wrote, that all of them must have arisen from the same source.
Presumably, one devil developed the disease several years ago then spread it to its neighbors.
Pearse noted that inbreeding, and the resulting lack of genetic diversity, may make Tasmanian devils particularly susceptible to this type of infection.
Since the animals are so genetically similar, their immune systems may not recognize the new cells as alien invaders that need to be fought.
It's like humans receiving organ transplants, she wrote—the transplant is less likely to be rejected by the body if the new organ is from a close relative. In the case of the devils,
The officials note, however, that there are "significant practical challenges" to attempting to enforce quarantine in the wild. (source:http://news.nationalgeographic.com/news/2006/02/0227_060227_tasmanian_2.html)