Australia’s 10 worst invasive species

Research has shown that invasive or pest species are a major problem for four out of five Australian threatened species, with rabbits, feral pigs and cats among the most destructive.

Research conducted by the Threatened Species Recovery Hub in collaboration with the University of Queensland identified the top 10 invasive species, based on the number of threatened species they affected. 

UQ School of Earth and Environmental Sciences researcher Stephen Kearney said people might be surprised by the list.

“Rabbits are our most destructive invasive species, having an impact on more than 300 species, including both threatened plants and animals,” Mr Kearney said.

“Rabbits destroy plants and can stop them regenerating by eating the seedlings, they compete with native grazing animals for food, and boost the number of predators like cats and foxes.”

Mr Kearney said the second most problematic species in Australia was a plant disease called rot root fungus, also known as phytophthora, affecting more than 200 threatened native plants.

“Feral pigs, in third place, have a negative impact on about 150 threatened species. 

“We don’t often talk about them, but feral pigs destroy vast areas of crops, wetlands and floodplains in northern Australia, and they dig up and eat sea turtle eggs and hatchlings along beaches.”

“Cats are in fourth place affecting 123 threatened species, and they have a particularly devastating effect on Australia’s small to medium sized mammals.

“Foxes, in seventh place, are frequently in the media, but feral goats, in fifth place, actually affect more threatened species. 

“This does not mean foxes are not a problem, it means there are other really problematic pests out there that as a community we have not been talking about as much.”

The other invasive species in the top 10 are the weeds, lantana and blackberry, and also black rats and feral cattle.

The Threatened Species Recovery Hub is a collaboration of 10 leading Australian universities and the Australian Wildlife Conservancy to undertake research to support the recovery of Australia’s threatened species. 

The research has been published in Pacific Conservation Biology.