The Tasmanian devil (Sarcophilus harrisii) is the world’s largest surviving carnivorous marsupial. This stocky, black-furred creature is found exclusively on the island of Tasmania, where it once thrived as a top predator and scavenger. Known for its powerful jaws, fierce appetite, and unsettling nocturnal screeches, the species has faced a rapid decline in recent decades.
Current Conservation Status
The Tasmanian devil is officially classified as Endangered. This designation is consistently applied by leading conservation bodies, including the International Union for Conservation of Nature (IUCN) Red List, the Australian Commonwealth government, and the Tasmanian state government. Being listed as Endangered means the species is facing a very high risk of extinction in the wild in the near future.
This status reflects the devastating loss of the wild population, which has plummeted by an estimated 80% overall since the mid-1990s. The most recent population estimates suggest fewer than 25,000 mature devils remain in the wild.
The Devastation of Devil Facial Tumor Disease
The primary driver of the Tasmanian devil’s decline is Devil Facial Tumor Disease (DFTD), a rare and aggressive form of transmissible cancer. Unlike most cancers, DFTD is a clonal cancer—meaning the living cancer cells themselves are transferred between individuals. The disease spreads primarily through biting, which is a frequent behavior during social interactions like mating and fighting over food.
Two distinct strains, DFT1 and DFT2, have been identified, with DFT1 being the most widespread across Tasmania. Once an animal is infected, tumors begin to form around the mouth and face, quickly growing into large, ulcerating masses. The tumors interfere with the devil’s ability to eat, which means the disease is almost universally fatal, often causing the animal to die of starvation within six to twelve months.
The lethality and mode of transmission have allowed DFTD to spread rapidly through the wild population, causing localized declines that have exceeded 90% in some areas. The disease disproportionately affects sexually mature adult devils, which are the most likely to engage in the aggressive social behaviors that transmit the cancer.
Other Threats to Survival
While DFTD is the most destructive, other human-related factors compound the pressure on the wild population. Roadkill is a significant cause of non-disease mortality, particularly in areas where devils forage near human settlements. The devils are nocturnal and naturally drawn to roads to scavenge on other animals killed by vehicles. The dark color and low stature of the devil make it difficult for drivers to spot at night, and it is estimated that about one devil is killed on the road every night.
Habitat loss and fragmentation also contribute to localized threats, forcing devils into closer contact with human infrastructure. Though the devil is adaptable to different habitats, the destruction of woodland remnants and the disturbance of traditional den sites pose a threat to breeding success.
Saving the Species
Conservation efforts are intensely focused on preventing the devil’s extinction, utilizing a two-pronged approach centered on population management and disease research. A comprehensive captive breeding program has established an “insurance population” of healthy, disease-free devils to safeguard the species’ genetic diversity. These animals are housed in biosecure facilities, including some on mainland Australia and on disease-free islands like Maria Island, to ensure a genetically representative backup exists should the wild population collapse.
In parallel, scientists are working on strategies to allow devils to coexist with the disease in the wild. Research is actively pursuing the development of a vaccine that could protect wild devils from DFTD. There is also a focus on identifying and managing naturally resistant devils, as some wild populations have shown signs of rapid evolutionary adaptation and even tumor regression. Efforts to mitigate roadkill, such as using soft release tactics to acclimate captive-bred devils and installing virtual fence technology, are also being implemented to reduce non-disease mortality.