Reintroducing top predators such as dingoes and Tasmanian devils into landscapes may help protect Australia’s diminishing biodiversity, say researchers. Australia should consider actively conducting a large-scale project
where populations of native top predators – the dingo and the Tasmanian devil –are allowed to recolonise habitats where they once occurred as a way of restoring fragile ecosystems.
In an opinion piece to be published in Trends in Ecology and Evolution, next month, ecology expert Dr Euan Ritchie from Deakin University Australia and international colleagues argue that top predators such as the dingo (Canis lupus dingo) and Tasmanian devil (Sarcophilus harrisii) can help ecosystems buffer against or ameliorate significant environmental challenges, including biological invasion, disease transmission and climate change.
“I acknowledge this is a pretty radical argument and there are some negative effects that must be addressed but we believe it is something land managers need to consider, desperate times need bold measures,” Dr Ritchie said. Australian ecosystems have become fragile and degraded and had a low ability to respond to challenges mainly due to the loss of native species, the functions they fulfilled, the loss of biodiversity, the invasion of pests and the consequent changes this wreaked on habitat. “In the Australian tropics alone, more than 20 native species of mammal might face extinction over the next few decades owing to inappropriate fire regimes, livestock grazing and predation by feral cats”.
The recent introduction of the red fox into Tasmania and the decline of the Tasmanian devil, a native top predator, is predicted to cause extinction of many species formerly abundant on mainland Australia and Tasmania. “We would argue that this grave situation justifies seriously considering management programs where top predators are reintroduced or allowed to recolonise habitats where they once occurred.” Dr Ritchie said recent evidence suggested that the reintroduction of dingoes would produce a cascade of benefits by limiting native and introduced herbivores (e.g. kangaroos and goats) and exotic predators, namely foxes and cats. “This would also have a profound flow on effect for other smaller species and vegetation,” he said.
Dr Ritchie acknowledged some livestock producers would have concerns about the potential impact of the predators on their stock. “But, we believe that livestock guardian animals present a viable option for protecting stock against these top predators, they may also help deter smaller predators like cats and foxes. Dr Ritchie also cautioned that top predators could in some circumstances increase the risk to threatened or endangered prey species, particularly those living in habitats already degraded by humans,” he said. “In areas where the risk to threatened species is too great it would be worth considering management that simulates the top predators’ effects on the local habitat”.
The above news item is reprinted from materials available at Deakin University via ABC Science. Original text may be edited for content and length.