Dingo poisoning found to disrupt ecosystem

13 March 2014

A study published this week by Dr Mathew Crowther and collaborators has found that the systematic poisoning of dingoes- the top predators in the Australian bush - has a deleterious effect on small native mammals.

Poisoning the top predators in the Australian bush has a negative effect on small native mammals
Poisoning the top predators in the Australian bush has a negative effect on small native mammals

"The study compared national parks in NSW that have been baited with those that haven't been," explained Mat. "There are generally more foxes in areas that have been baited, due to lack of competition with dingoes." It is these foxes that cause the problems for small native mammals, many of whom are endangered.

"In the baited areas there are also more non-endangered kangaroos and wallabies, as they are the main prey of dingoes." The resultant increase in macropod grazing decreases the understory vegetation. "We found the understory vegetation is depleted where the dingoes have been baited, which is where the small mammals live."

"In contrast there are more small native mammals, including native rodents, dasyurid marsupials and bandicoots where there is no baiting."

"If you bait to get rid of dingoes, you cause the loss of small mammals due to increases in foxes, and decrease in cover."

It is the first study to show how removing large carnivores can result in simultaneous population outbreaks of herbivores and smaller predators. And that these population outbreaks, in turn, can have deleterious effects on smaller mammals.

"These findings also add to our body of work from arid Australia demonstrating the major role dingoes have in regulating ecosystems throughout the continent, and their effects is great in both forest and arid ecosystems."

The research is published in the Proceedings of the Royal Society B and the research team included collaborators at the University of Western Sydney and the University of New South Wales.

Co-author Dr Mike Letnic (UNSW) said "Dingoes should not be poisoned if we want to halt the loss of mammal biodiversity in Australia. We need to develop strategies to maintain the balance of nature by keeping dingoes in the bush, while minimising their impacts on livestock."