After being absent for three millennia, Tasmanian devils have returned to mainland Australia.
Tasmanian devils have been reintroduced into the wild in mainland Australia for the first time in 3,000 years. Scientists hope that the predators’ release can help balance ecosystems devastated by invasive species. Species recovery organisation Aussie Ark has collaborated with non-profits Global Wildlife Conservation and WildArk to release 26 captive-raised individuals into an expansive 1,000 acre fenced sanctuary named Barrington Wildlife Sanctuary in Barrington Tops, eastern Australia.
Tasmanian devils are marsupials renowned for their ferocity and powerful bone-crushing jaws. Their name originates from their high-pitched squeals and they are famous for their gritty fights over access to animal carcasses. The species is classified as endangered, with the population of wild individuals in Tasmania estimated to be less than 25,000. It is suspected that dingo packs contributed to their eradication on the mainland and, while some do still inhabit the island state of Tasmania, their numbers have declined over the past two decades.
During the 1990s, there were as many as 150,000 but the animal population was hit by a deadly and contagious mouth cancer that dramatically reduced numbers.
It is not known exactly why the species disappeared from Australia thousands of years ago, but researchers suspect that it was due to human activity; it is likely that, when early hunters destroyed the majority of the continent’s megafauna, the devils were left without food.
The individuals have been placed in the sanctuary to increase their chances of survival. The first group of 15 were released in March, with the team using radio-collars to monitor them and putting out kangaroo carcasses while they adjusted. Following indications that all the individuals were thriving in their new environment, a further 11 were released in September. It is hoped that the young, healthy individuals selected will be ready for the breeding season beginning in February. Over the next two years, another 40 individuals are set to be released and Aussie Ark hopes that over time they will be able to release further animals into unfenced areas.
Tim Faulkner, president of Aussie Ark, says, “They’re free. They’re out there. We’ve got some basic means of keeping an eye on them. But essentially, now it’s over to the devils to do what they do.”
To prepare for the release, the team fenced off a large area of protected eucalyptus forest, removed invasive plants, cleared leaf litter that cause forest fires, and used ‘humane lethal control’ to get rid of red foxes and feral cats – introduced predators that have decimated the continent’s small mammal populations. The devils’ presence causes predators such as these to hunt at dawn and dusk to avoid run-ins with the nocturnal devils. This small behavioural shift can protect night-dwelling native species, such as bandicoots, which increase in numbers where devils are more prominent than cats. The team hope that the devils’ release will thus stabilise the continent’s ecosystems against invaders.
Other threatened native species have also begun to be released into the same sanctuary, such as Parma wallabies, long-nosed bandicoots, long-nosed potoroos, and rufous bettongs, with plans for further species to be released over the next six months. These miniscule mammals are vital in maintaining a clean and healthy environment by dispersing seeds and reducing wildfires by digging up leaf litter and accelerating its decomposition.
“It really comes down to these smaller, terrestrial ecosystem engineers that turn over leaf litter,” explains Faulkner. “A bandicoot turns over an elephant’s [weight] of soil each year. One bandicoot.”
If the releases prove positive, there are 370,000 acres of further protected land nearby in which the reintroductions could potentially spread.
“I really believe that over time, we’ll see the devil become a normal part of mainland Australia,” says Faulkner. “It was here 3,000 years ago. You know, that’s an ecological blink of an eye.”