Scientists favour return of Tasmanian devils; say they will restore ecosystems

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Extensive dingo culls in Australia have led to an ecological imbalance and to restore this balance reintroduction of Tasmanian devils to the mainland could be one of the best ways, researchers have suggested.

According to ecologists from University of New South Wales, if Tasmanian devils are reintroduced they will improve biodiversity by limiting the spread of red foxes and feral cats in habitats where dingoes have been culled. Tasmanian devils (Sarcophilus harrisii), which once lived across the Australian continent, went extinct on the mainland about 3,000 years ago and scientists believe that dingoes are to blame for that.

However, recent extensive dingo culls to protect livestock has not only created an ecological balance, but has also paved way for restoration of the devils that will help put brakes on the worsening Australia’s extinction crisis.

Owing to dingo culls, there is an urgent need of a predator that can suppress fox numbers, which have wreaked havoc by targeting native mammals. Researchers have, for the first time, studied the impact of reintroducing Tasmanian devils to forest ecosystems in South Eastern parts of New South Wales and the outlook seems positive.

“The devil is the obvious answer. It doesn’t pose as serious a risk to livestock, and it has played a major role in stopping foxes from establishing a foothold in Tasmania”, says PhD candidate Daniel Hunter from the UNSW School of Biological, Earth and Environmental Sciences.

In a study published in the journal Biological Conservation, the authors have suggested that the marsupial could restore important ecosystem functions once performed by dingoes. Further, this reintroduction could help ensure the long-term survival of the devil, which has seen massive population decline over the last two decades from devil facial tumour disease.

The team reviewed previous studies to understand more about the ecological impacts of dingoes, devils and foxes, and then applied this information to their models, which tried to predict how a range of ecosystems would respond to the presence of devils.

These models mapped out different scenarios in which the re-introduced devil co-existed with varying populations of the two other predators: ranging from completely eradicated, to reduced, and abundant.

Their results suggest that reintroducing devils would result in fewer foxes and feral cats, as well as grazing herbivores such as wallabies, which remove vegetation that helps smaller animals hide from predators.

“We suspect that they help control the fox and cat populations by directly attacking them and their young,” says co-author Associate Professor Mike Letnic from UNSW. “There is very good evidence from Tasmania that cats modify their movements and numbers are lower where there are healthy devil populations.”

The research also suggests there would be benefits for small and medium-sized animals, such as bandicoots and ringtail possums, as well low-lying vegetation. However, threatened species vulnerable to fox predation benefited little from devil introduction.

“Devils aren’t a silver bullet, but we think that they could do a lot of good on the mainland, and this study indicates that a monitored process of reintroduction could actually work,” says Associate Professor Letnic. “We need to take action to arrest the extinction crisis we have in Australia, and that requires being bold and trying something new.”