Feral deer could become Australia's next feral pig, leaked report warns

Australia is failing to stop the spread of feral deer, an invasive pest that costs the country more than $91m a year in production loss and management time, according to an unpublished government report.

The report covers the five years from 2020 to 2025, over which the national feral deer action plan was assessed. During that period the elusive animals increasingly encroached on major cities, leading to more frequent encounters — including an occasion when two men were fined after becoming lost in the bush when they were spooked by deer while nude sunbathing.

The report describes deer as one of Australia's "most rapidly increasing invasive pests" and says they have both increased in number and spread in territory.

One state stands out

Six species of feral deer are established in Australia — chital, fallow, hog, red, rusa and sambar — with the densest populations across south-eastern Australia. Smaller, more localised populations are found in South and Western Australia and the Northern Territory.

The report card, produced by the National Vertebrate Pest Coordinators, shows every state and territory failing or floundering on deer control, with one exception. South Australia, which launched a statewide eradication plan in 2022, received a green mark in all four categories assessed under the traffic light system, with high confidence that it had reduced deer abundance, distribution and environmental and agricultural impacts.

New South Wales and Tasmania were given reds in all four categories, while Queensland and the ACT each received three reds and a yellow. No jurisdiction other than South Australia received a single green pass mark.

Prof Euan Ritchie, of Deakin University and president of the Australian Mammal Society, said he was "not at all" surprised by the findings. "This report shows that governments are failing miserably to invest enough to control deer populations and the severe impacts that they can have on agriculture, native wildlife and the environment, road safety and culturally significant sites," he said.

'The next feral pig'

Invasive Species Council advocacy manager Reece Pianta said the report, which was leaked to his organisation, pointed to "a long-term systemic underfunding of deer control". In May 2025 the council released footage and images it said showed the Gold Coast "under feral deer siege".

"Deer are the next feral pig," Pianta said. "The difference with deer is that an intervention now could make a significant difference to the population numbers and contain, or even reverse, that spread."

Pianta said deer probably could not be eradicated from the whole continent, but South Australia's results showed it was possible in some states and territories, while others would need a long-term effort to contain the spread and limit the damage.

Prof Andrew Lowe, director of the Adelaide University Environment Institute and a member of the Hills and Fleurieu Landscape Board, called the report a "good news story" for South Australia. He said the state began tackling its "massive problem with deer" in earnest from 2022, after an estimate showed the $36m of damage caused annually by deer there was set to rise to $241m by 2031.

Deer have "massively declined" since a $4m eradication program began, Lowe said, though the animals are seeking refuge on the fringes of urban areas where culling is more expensive. Functional eradication from South Australia would take about another $10m over 10 years, he said, against far larger costs if nothing is done. "So $10m versus $240m – do the math."

Source: The Guardian World.