Rabbit control funding gone

But there was nothing in federal budget for the national rabbit control program, which runs out of funding on June 30, jeopardising research into new control measures.

Back when the myxoma virus or "myxo" was released in 1950, it killed 99.8 per cent of infected rabbits. Since then, the effectiveness of Australia's rabbit control viruses has been dwindling. The 2017 release of RHDV1-K5 knocked down just 34pc of rabbits.

In eastern Victoria, Procull's Dave Rowlands can't keep up with demand.

"The virus just isn't working or the rabbits have become immune to it, but we've got rabbit work coming out our ears and the proverbial at the moment," he said.

It reminds the 54-year-old of his childhood on a West Gippsland dairy farm when, aged 6, he learnt to shoot rabbits until myxo brought them under control. Now, Mr Rowlands and his own daughter is out again with his own daughter, shooting hundreds of rabbits a night.

West of Broken Hill at Thackaringa Station, grazier David Lord is seeing numbers explode, too.

In 2002/03, he ripped about 28,000 warrens on his 66,000-hectare station. Together with biocontrols, it held the population at bay for years. Now that the drought's broken and the insects are back to carry the viruses, rabbit numbers should be under control.

"I'm not seeing the numbers decline," Mr Lord said. "Now, that's really, really scary."

Rabbits are developing a natural immunity to the haemorrhagic viruses and, ironically, well-intentioned land managers are making things worse.

Releasing a haemorrhagic virus during breeding season can be disastrous because rabbits less than 10 weeks old won't die. Instead, it provides life-long immunity to the virus.

Research released by the University of NSW in January showed that 74 per cent of releases in Australia were done at the wrong time. In a good season like this one, rabbits could breed year-round, creating a double whammy of ballooning populations and immunisation created by mistimed releases.

That, Centre for Invasive Species Solutions chief executive Andreas Glanznig said, showed why his centre wanted to reintroduce a national coordinator.

"Australia's tended to focus more on on on the science as opposed to the people side of things and that new evidence highlights how we're not getting the best value from the biocontrol agents that we have at the moment," he said.

It's all created a race between the growing immunity of the rabbits and the development of new virus strains.

Scientists have begun culturing viruses in petri dishes rather than in rabbits, hoping they will find new mutations that might evade immunity quicker. Still, it can be years before any new control measures are allowed to be implemented.

"Not only have you got to do the science, then you're going to spend three years or so working through all these regulatory and policy approval processes," Mr Glanznig said.

But hopes of a long-term solution are now pinned on a new form of control: genetic infertility. The question is whether there's enough long-term funding to match, Rabbit Free Australia chairman Adjunct Professor Wayne Meyer said.

"Given the kind of decreased effectiveness associated with viruses, you could see very large numbers of rabbits coming again," Adj Prof Meyer said.

"Unless you've got something in the pipeline and being worked on for 10 years from now, you're simply not going to have anything to replace them."

Thackaringa's David Lord said there was no "plan B" without effective biological controls.

"The government's going to drop the ball by removing funding from biocontrol and what we did in terms of mechanical habitat destruction is not possible in a lot of parts of Australia," he said.

A government spokesperson said it was investing over $650,000 until June 2024 in rabbit biocontrol research with the NSW Department of Primary Industries and test rabbit haemorrhagic disease virus delivery methods.