Dingoes could be the answer to Australia’s wildlife decline

Australia’s mammals are going extinct at an alarming rate. Invasive rabbits are gobbling up all the native plants, and feral cats are preying upon the rabbits when they can, and just about everything else with a pulse when they can’t. Introduced red foxes do a fair bit of damage as well. Attempts to curb the plague of invasive creatures are met with resistance because lethal methods are unpalatable to many folks, because they’re costly, and because they require long-term planning and persistence to have even a minute chance of being effective.

But one strategy for restoring order and an ecosystem out of balance that’s tried and true is restoring apex predators to those landscapes after they’ve been wiped out. If it isn’t yet called the “Yellowstone strategy,” it probably ought to be. For Australia, the analogue to the grey wolf would be the dingo, Canis dingo.

Throughout much of their historic range, dingoes have been wiped out due to exclusion or lethal control. But theoretically, dingoes should be able to suppress smaller predators like feral cats and red foxes through competition, which would benefit small rodents and marsupials due to reduced predation. Dingoes should also be able to suppress medium-sized herbivores like feral goats and native kangaroos through predation. Left alone, those herbivores would proliferate and overgraze the vegetation down under. Still, other researchers have argued that the dingo doesn’t control smaller predators as well as might be expected, and that the large canid comes with its own problems in terms of over-predation.

Still, University of Sydney researcher Thomas M. Newsome argues, together with his colleagues in the journal Restoration Ecology, that there is a need to “further define the ecological role of the dingo” to see whether it merits a reintroduction analogous to that of the Yellowstone wolf. They propose a large, landscape-scale experiment to determine what reintroducing the dingo might mean for Australia’s wildlife.

Here’s what it might look like:

There is currently a 5,500 kilometer-long dingo-proof fence separating New South Wales from Queensland and South Australia, meaning that New South Wales (NSW) is essentially devoid of the predators. Newsome’s idea is to relocate part of that fence to the opposite side of Sturt National Park, located in the northwestern edge of the state. That would open up the park to colonization by dingoes, while continuing to protect the rest of NSW.

The park isn’t just an ideal site because of its location adjacent to the fence; it’s also ecologically ripe for the experiment. Dingoes, red foxes and feral cats are all extant within the park, and dingo abundance would increase if the dingo-proof fence was realigned and if the park ceased its lethal control of the dingoes. In addition, the park is home to numerous red kangaroos and emus, and a fair number of feral goats, European rabbits, and feral pigs, all of which would provide opportunities to assess the effects of dingoes on a variety of bird and mammal species. There are also many populations of native rodents and smaller marsupials within the park, allowing researchers to assess whether the dingoes suppression of smaller predators would prove beneficial to the smallest critters. The 3,000-square-kilometer park is large enough to sustain several individual packs of free-ranging dingoes.

Such an ambitious plan would require adjusting state laws currently requiring Sturt National Park to control dingoes. Livestock farmers and local communities adjacent to the park would have to be convinced of the plan’s long-term value.

Researchers would need to divide the park up into monitoring plots and spend 1-3 years establishing baseline data before moving the fences and adjusting the park’s dingo policies. Newsome recommends that monitoring continue after dingoes are allowed to roam the park for at least five years, or longer if prolonged dry periods impede their ability to recolonize or enhance their ability to suppress other predators. “It would be ideal to run the experiment over multiple wet and dry cycles,” he writes.

From a scientific standpoint, the plan seems sound. From a cultural standpoint, things are trickier. The researchers point out that it took twenty years of divisive debate before wolves were eventually allowed back into Yellowstone. Similarly, “it is likely that the idea of a dingo reintroduction in Australia would spur a strong and emotive debate,” they say. However, the tale of the Yellowstone wolf also provides evidence that such a plan could work – the challenge would be to effectively communicate that to various stakeholders. The key, they say, would be to focus on the positive effects of predator reintroduction, rather than focusing on advising people on how to avoid negative encounters with large carnivores.

Newsome and his colleagues acknowledge that the plan is bold, and say that it is purposefully so. “Our proposal—a controlled dingo reintroduction experiment at a scale large enough to generate meaningful results—would, if implemented as suggested, actually resolve the long-running debate: whether the dingo can help halt Australia’s biodiversity collapse and help to restore degraded rangeland environments.” And that would allow policymakers to have actual, empirical information in their hands when making wildlife management decisions. – Jason G. Goldman | 20 February 2015

Source: Newsome T.M., et al. (2015). Resolving the value of the dingo in ecological restoration, Restoration Ecology. DOI: http://dx.doi.org/10.1111/rec.12186

Header image: Bob Tamayo.