Why the Tasmanian Devil Is Endangered

The Tasmanian devil (Sarcophilus harrisii) is a raccoon-sized marsupial—the world's largest carnivorous marsupial, in fact—found almost exclusively on the Australian island state of Tasmania. The stocky critter, with its characteristic black fur and distinctive white markings, is thought to have become extinct from the mainland hundreds if not thousands of years ago. However, a small population has been reintroduced in New South Wales due to threats of extinction.

The International Union for Conservation of Nature (IUCN) declared the "Tassie" devil endangered in 2008, the first time populations had been assessed since 1996, when it was listed as a species of least concern. Australia's native marsupial has faced many challenges, including an infectious facial cancer and widespread persecution at the hands of humans, which have caused its numbers to drop from up to 150,000 in the '90s to as few as 10,000 now, and populations are ever decreasing.

Learn about the threats these endangered devils face and what we can do to help save them.

Threats

A species-specific disease has nearly wiped the Tasmanian devil completely out since the '90s; now what's left of the endangered animals must weather the perils of human encroachment and climate change.

Devil Facial Tumor Disease

The IUCN has identified Devil Facial Tumor Disease (DFTD) as the primary threat to Tasmanian devils. DFTD encompasses the only two known contagious cancers in the world, DFT1 and DFT2, which are transmitted through biting. Because biting is a common mating behavior and DFTD is fatal in almost all cases, the infectious disease has decimated the Tasmanian devil population—by as much as 95%, in some cases—since it was first observed in 1996.

Predators

Back when Tasmanian devils roamed the big island, dingoes were their top predator. The introduced wild dogs played a large part in the devils' local extinction, but even in Tasmania, where dingoes couldn't get to them, a different kind of canine would eventually become a threat to remaining populations.

At the time of the IUCN assessment, domestic dog owners reported about 50 devils killed by dogs per year, believed to be a small fraction of the estimated "several hundred" instances that went unreported.

Human Activity

Humans are another major predator. Road kills are the second biggest threat to Tasmanian devils after DFTD, killing an estimated 2,205 devils per year at the time of the IUCN assessment. The report revealed that car accidents were responsible for 50% of Tasmanian devil deaths in Cradle Mountain National Park, a popular tourist destination that sees more than 200,000 visitors annually.

In 2017, a University of Sydney study reported that devils that were reintroduced to the wild after periods of captivity were more likely to be hit by vehicles because they had become "naive to wild conditions," lead study author Catherine Grueber said. This adds extra complexity to captive breeding programs and other conservation initiatives to re-establish devil populations.

To a lesser extent, persecution has impacted the animals. More than 5,000 reportedly died per year after being poisoned by sheep farmers. "Current persecution is much reduced," the IUCN said in its assessment, "but can still be locally intense with in excess of 500 devils thought to be killed per year."

Climate Change

The IUCN's 2008 report does not list climate change as a major threat, but a later study of the largest ever genetic dataset of Tasmanian devils suggested that climate is a bigger issue than previously thought. Increasingly arid conditions across Australia leads to a lack of prey availability and habitat, the study found, and as the devil population dwindles, the gene pool gets smaller and smaller—which leads to lower resistance to diseases, among other complications.

What We Can Do

Until 1941, hunting Tasmanian devils was legal in Australia. After seeing the Tasmanian tiger be hunted to extinction, though, laws were passed to protect the species. Following the hunting ban, devil populations flourished. They might continue to flourish without the threat of DFTD. Here's what experts are doing to save the Tassie devil from extinction.

DFTD Research

It wasn't until 2010, 14 years after DFTD was first discovered, that researchers identified its origins as Schwann cells using a technique called deep sequencing. Research is advancing all the time to better understand the disease and why it spreads so wildly. In the 2014 study that delved into the impact of climate change on devils, for example, the authors asserted that smaller populations are more susceptible to DFTD because of low genetic diversity.

Alongside exploratory research, prospective treatments and DFTD prevention methods are being discovered all the time. Among them is a cholesterol-lowering drug that could help delay the spread, proposals to isolate local populations, and a vaccine that could be given to wild devils via edible bait.

Captive Breeding

Breeding programs such as the Tasmania Zoo's Devil's Heaven and Aussie Ark's Devil Ark breed the devils methodically for maximum genetic diversity. The animals are kept in large enclosures and reintroduced to the wild in both Tasmania and mainland Australia. Updates from Devil Ark reveal that efforts to curb DFTD this way have not proven successful yet, but experts remain hopeful that the species' resiliency will benefit from higher genetic diversity and greater numbers.