Tasmanian devils are the largest surviving marsupial predator. They have been confined the island of Tasmania for cenuries if not milennia. The future of the animals appeared bleak because of a ravaging disease. But the Tasmanian devil future is now brighter according to the Washington Post.
Dozens of devils have been released in New South Wales, the paper said, and it is now confirmed that seven babies have been born in the nearly wild. The devils are currently in a 1,000 acre fenced off area that allows them to acclimate and engage in normal behaviors prior to full release. It is a process similar to that used with other rewilding projects. the “new” animals are not released into an unfamiliar habitat without monitoring and acclimatization.
This project is being led by Aussie Ark. The organization was founded in 2011 with a specific mission of saving the iconic sharp-toothed predator. It has since expanded its role to protect more of Australia’s threatened wildlife.
Australian wildlife is under threat, much of it from feral cats and other invasive species.
The devils have been threatened by a number of factors, including disease.
Since the 1990’s Australian conservationists have been trying to rescue Tasmanian Devils from the ravages of Devil Facial Tumor Disease (DFTD). The cancer is fatal in more than 80 percent of cases.
he disease is a virus induced cancer exclusive to the species. It has been under extensive study for over 10 years. Early research was handicapped by a lack of knowledge of the disease and a lack of knowledge of the devils. Researchers now have a fuller understanding of the disease and its causes. They also know much more about the devils immune response – and the evasion techniques of the virus. Transmission appears to be through intimate contact. Biting is thought to be a major transmission source.
Tasmanian devils are the largest marsupial carnivore weighing up to 26 pounds. They are mostly nocturnal and are both scavengers and hunters eating prey as small as insects and as large as snakes and reptiles. One discovery has been of a population of devils that seems to show resistance to the disease.
The resistance to the disease exhibited by the colony of devils appears to be counterintuitive. Devils have a low diversity of certain genes that that fight off disease. In most cases the more diverse the genes are, the stronger the immune system. It was assumed that the low diversity was the reason the virus could enter the devils.
Research on the immune devils suggests that low diversity might actually be a strength. The virus passes into the devils because the immune system in most devils does not recognize the virus as foreign. But it may be that the devils with the less diverse immune are more likely to recognize the virus and destroy it.
This is because the devils immune system has two genetic sequences. The virus has parts of both. Since most devils have both genetic sequences the virus is not recognized as foreign. The more immune devils have only one or the other sequence. When the virus enters these devils, the immune system recognizes the unknown sequence and destroys the virus.
This may lead to a change in strategy for the Tasmanian devil future away from interbreeding to expand diversity and toward isolation, allowing the immune devils to survive and eventually, it is hoped, thrive.