A rare contagious facial cancer will kill off Tasmania's devil
(Sarcophilus harrisii) in the wild within twenty-five years. No cure for the disease has been found, but biologists have isolated the cause as
cancerous Schwann cells passed from one devil to another. Schwann cells normally insulate nerve fibers. Previously it was thought the facial tumors might be caused by a virus. The bleak news is offset by a precedent setting partnership between the University of Sydney and the San Diego Zoo. A joint project will reintroduce 50 disease free devils onto Maria Island off Tasmania's east coast. The population will be managed to insure genetic diversity and protection from the disease. The rescued devils will be dispersed back into the wild once it is safe to do so. University of Sydney is known for specializing in sequencing the Tasmanian devil's genome. San Diego Zoo contributed $500,000 to project including the funding of a conservation geneticist at the University. Genetic sequencing revealed that devils' have low genetic diversity and also low genetic immunity for thousands of years before the emergence of the contagious facial tumors. Because of their genetic similarity the have no immune response to invading cancer cells. Probably because of these genetic factors, devils have experienced population extinctions and crashes due to disease outbreaks in the past. The population of devils was estimated at 65,000 to 75,000 in the mid 90's. The population is now around 10,000 to 25,000 due to the disease but also habitat destruction and culling. Devils limit the number of foxes, an introduced species, as well as feral cats and dogs because they feed on carrion. Devils also kill young foxes in their dens. Their absence from Tasmania's forests is considered an ecological problem since the exotic red fox will become established in their absence.
