Australia Fails to Contain Rapid Spread of Invasive Feral Deer
An unpublished government report reveals that Australia is failing to halt the spread of feral deer, which one advocate warns could become “Australia’s next feral pig”. The national feral deer action plan assessment, covering the period from 2020 to 2025, shows that six established deer species have increased in numbers and expanded their territory, now costing more than $91m in production loss and management time every year.
Rapid Spread Threatens Environment and Agriculture
Feral deer populations have increasingly encroached upon major cities across south-eastern Australia, where densities are highest. Six species are now established in Australia: chital, fallow, hog, red, rusa, and sambar. There are smaller, more localised populations in South and Western Australia and the Northern Territory.
Prof Euan Ritchie, president of the Australian Mammal Society, stated that governments are failing to invest adequately to control the animals. “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,” Ritchie said.
State-by-State Assessment Highlights Wide Failures
The national vertebrate pest management report card evaluated jurisdictions using a traffic light system across four distinct categories. Every state and territory is failing or floundering in their efforts to control feral deer, with one notable exception. New South Wales and Tasmania received reds in all four categories. Queensland and the ACT each received three reds and a yellow.
In contrast, South Australia stood out as the sole exception. The state launched an ambitious statewide eradication plan in 2022 and received a green in all four categories assessed. The report showed – with high confidence – that the state had decreased the abundance, distribution and environmental and agricultural impacts of deer.
Advocates Warn Deer Are the Next Feral Pig
Reece Pianta, advocacy manager for the Invasive Species Council, said the report confirmed what land managers had been seeing on the ground for some years. In May 2025, the council released footage and images that it said showed the Gold Coast “under feral deer siege”.
Pianta pointed to a long-term systemic underfunding of deer control. He said deer did not have the recognition of other more notorious invasives, but controlling them was every bit as necessary. “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.”
South Australia Proves Eradication Is Possible
Prof Andrew Lowe noted that South Australia grappled with its massive problem with deer in earnest from 2022. Agricultural impact estimates at the time projected that annual damages worth $36m would increase to $241m by 2031.
Following a $4m eradication program, deer had “massively declined” in South Australia. However, deer were seeking refuge on the fringes of urban areas, where culling was more expensive. Lowe, who is also a member of the Hills and Fleurieu Landscape Board, estimated that functional eradication of deer from SA would take about another $10m over 10 years.
“If we don’t do that, then the population will go up again and we’re going to be in the same situation,” Lowe said. “So $10m versus $240m – do the math.”
Frequently Asked Questions About Australia’s Feral Deer Crisis
How much does feral deer damage cost Australia annually?
Feral deer cost more than $91m in production loss and management time every year. In South Australia, annual damages were estimated at $36m, which was set to increase to $241m by 2031.
Which deer species are established in Australia?
There are six established feral deer species: chital, fallow, hog, red, rusa, and sambar. The highest population densities are concentrated in south-eastern Australia.
Why did South Australia receive positive marks in the government report?
South Australia received a green in all four categories assessed after launching an ambitious statewide eradication plan in 2022. The report showed the state had decreased the abundance, distribution and environmental and agricultural impacts of deer.
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