Tasmanian devils, known for their fierce temperament, have been plagued by a contagious facial cancer in recent decades. Courtesy photo: AUSSIE ARK
Written by JASON BITTEL
Tasmanian devils have disappeared into the forests of mainland Australia for 3,000 years. Now, thanks to ongoing re-introduction efforts, 26 of these endangered critters have been able to return to Australia.
Tasmanian devils are marsupials, the size of pet dogs, and are known for their powerful jaws, which can tear large animal carcasses to pieces in minutes. However, in the 1990s, the Tasmanian devil species contracted a deadly form of infectious oral cancer, which reduced its remaining wild population to just 25,000, all of which are found on the Australian island of Tasmania.
The cause of the extinction of the Tasmanian devil on the Australian continent three thousand years ago is unclear, but it is likely caused by human behavior. When early hunters hunted most of the continent's megafauna, the Tasmanian devil lost its food source.
As scavengers, Tasmanian devils play a vital role in maintaining a healthy balance in the ecosystem, which is why scientists have worked so hard to bring them back.
Tim Faulkner, president of species recovery group Aussie Ark, said: "We worked hard for more than a decade to reach where we are today. The group works closely with the nonprofit Global Wildlife Conservation Society and WildArk to release captive Tasmanian devils into barrington Tops National Park, which is about 405 hectares north of Barrington Mountain National Park in eastern Australia.
Despite their ferocity, "they are actually no threat to humans or agriculture," he added.
Even so, the reintroduction of animals remains fraught with uncertainty, so scientists tried to introduce 15 Tasmanian devils in March. The team used radio collars to examine released Tasmanian devils, while also placing kangaroo carcasses as food to help them adapt to their new homes. Scientists were optimistic after all the Tasmanian devils showed signs of thriving, so on Sept. 10 they released 11 more Tasmanian devils — now largely on their own.
"They're free, they're free to live in the wild," Faulkner said. "We have some basic ways to keep an eye on them. Fundamentally, though, it's time for Tasmanian devils to live freely. ”
Resist invaders
In preparation for the arrival of the Tasmanian devil, Faulkner's team circled a large protected eucalyptus forest, cleared out invasive plants, cleared away fallen leaves that could lead to forest fires, and used humane means to euthanize red foxes and stray cats, both introduced predators that destroyed small mammal populations on the australian continent.
Tasmanian devils enter their new home in eucalyptus forests in eastern Australia. Courtesy photo: WILDARK
Stray cats do not prey on Tasmanian devils. In fact, perhaps more important are these felines.
"The presence of Tasmanian devils seems to have had some impact on cats," said David Hamilton, an expert on Tasmanian devils and a research assistant, who was not involved in the Tasmanian devil reintroduction program. Tasmanian devils usually do not feed on cats, but rather cats are forced to prey at dusk and dawn to avoid conflict with Tasmanian devils.
This may seem trivial, but this small shift in behaviour could actually protect nocturnal native species such as the possum, several of which are listed as endangered in Australia. Interestingly, Hamilton said, there is an increase in the population of Tasmanian devils (as opposed to cats).
That's exactly what Faulkner and others hope Tasmanian devils can do for Australia: stabilize the continent's ecosystem and fend off invaders.
But what will happen when the Tasmanian devil confronts the Red Fox is a "huge unknown," Hamilton warned. The red fox is larger than a cat and is comparable in size to a tasmanian devil.
In addition, it remains to be seen whether the reintroduction of Tasmanian devils will have unforeseen consequences for other sensitive species. For example, in 2012, tasmanian devils were introduced to Maria Island off the coast of Tasmania, resulting in the extinction of several short-tailed stork communities.
Stray cats and broom-tailed possums are not native to the island, and both have begun to prey on seabirds. Although Tasmanian devils began to suppress these predators, they also began to eat seabird eggs and juveniles.
Hamilton said: "Theoretically, they should not have a negative impact [on Australia]." However, when you do something like this, you have to consider the entire ecosystem, which is a very important requirement. ”
That's why it's important to do the reintroduction in a vast and closed environment, he adds.
'Ecological Moment'
If all goes well, the three conservation groups plan to release another 40 Tasmanian devils in the same protected forest over the next two years. They will have companions.
Since the removal of stray cats and red foxes, Faulkner's team has also begun releasing other endangered native species into the same habitat, including the round-shielded kangaroo, the long-nosed kangaroo, the proboscis kangaroo and the red-brown kangaroo.
In addition to the Eastern Possum, Broom-tailed Rock Kangaroo and australian brown short-nosed possum, AussieArk plans to release more of these species over the next six months.
These small mammals can scatter seeds, dig up fallen leaves and accelerate their decomposition, thereby reducing the intensity of wildfires, which is essential for keeping the environment clean and healthy.
Faulkner said: "It's really thanks to these small terrestrial ecosystem engineers who flip the fallen leaves. A tasupet weighs the same amount of soil as an elephant each year. Just one possum is so powerful. ”
If the experiment is ultimately successful, he added, there are nearly 150,000 hectares of protected land nearby that could serve as habitat for reintroduced species.
Faulkner said: "I truly believe that over time we will see Tasmanian devils become a normal part of the Australian continent. They were here 3,000 years ago. This is just a blink of an eye ecologically. ”
(Translator: Stray Dog)