FARMERS need more funding, data and tools to hold the line against an advancing army of feral deer, pigs and goats, a long-await parliamentary inquiry report has found.
The Environment and Communication Committee, which took three-years to investigate the issue, estimated the annual cost to agricultural businesses from the three feral species "runs into hundreds of millions of dollars".
The committee's final report recommended long-term funding to implement the feral pig and deer national action plans, regular updates on their rollout and sharing best practice strategies.
Many of the recommendations were deer-specific, such as encouraging all states and territories to classify them as environmental pests rather than a game animal.
Invasive Species Council chief executive Andrew Cox said while still incredibly destructive, farmers had learnt to live with pigs and goats, but deer were a new and rapidly expanding threat - in NSW alone deer were expanding by a million hectares every year.
The latest ABARES pest survey found feral deer were the most commonly reported pest animal that recently arrived on properties, more so than kangaroos, feral pigs and wild dogs.
"The inquiry reinforced the alarming finding that the potential distribution of deer could occupy almost the entire continent," Mr Cox said.
"We're at a point where we need to hold the ground, draw a line in sand and stop the advance."
The committee heard evidence from landholders that feral deer had caused water spoilage, erosion, damage to fences, tree crops and shelter belts, along with increased competition in grazing pastures.
The report recommended all levels of government commit to eliminating feral deer populations in World Heritage Areas, areas of national environmental significance and national biodiversity hotspots.
It also suggested a standalone Key Threatening Process listing for feral deer under the EPBC Act be adopted, accompanied by a Threat Abatement Plan, to elevate the focus on controlling deer impacts.
Centre for Invasive Species Solutions was singled out by the committee for more long-term funding beyond its current 2022 grant.
Six of the recommendations were specifically focused on continuing the work already developed through the centre, including the National Feral Deer Action Plan.
CISS chief executive Andreas Glanznig said his organisation had a strong track record of delivering results, pointing to the rabbit biocontrol program and the National Wild Dog Action Plan.
"We have known feral deer are an emerging national issue for many years now," Mr Glanznig said.
"Sustained funding [would] ensure we have the same number of integrated tools to manage feral deer as we do for rabbits and wild dogs."
Committee chair Senator David Fawcett, said landholders should be empowered to manage feral animals on their land.
"The impact of feral species is expensive and landholders bear much of this cost," Senator Fawcett said.
"Feral pig management alone is estimated to have cost Australian landholders $47.7 million in 2019.
"The Committee also recognised that effective feral species management is delivered through the coordinated efforts of all stakeholders including landholders and all three tiers of government."
Mr Cox applauded the committee's recommendation to direct the Productive Commission to review the costings and funding models necessary to manage invasive species.
"I think it'll highlight the benefits of early action," he said.
"If we act now, we can give relief to future landowners that would be measured in the billions of dollars."
Of the 17 recommendations, Mr Cox was "a bit nervous" about the one calling for the commercial harvesting of feral deer.
"That could be of benefit, but it's at risk of locking in the damage," Mr Cox said.
"Goats are a good example of how commercialisation has aided and abetted the situation, with farmers harbouring goats to the detriment of the environment."