After a high of 600 million rabbits in the 1940s, the introduction of several rabbit biocontrol agents since the 1950s have played a critical role in reducing rabbit numbers and their impacts.
A new report released on March 21 by Centre for Invasive Species Solutions shows the combined efforts of scientists, governments and land managers to control the pest have resulted in huge benefits for primary producers and threatened species.
“The value of new rabbit haemorrhagic disease virus variants naturalised since 2014 to Australian agriculture is expected to save $4 billion over the next 30 years,” centre chief executive Andreas Glanznig said.
“This builds on the benefits already achieved over a 60-year period of $81.8 billion, following the release of the myxoma virus in 1950 and the first rabbit haemorrhagic disease virus in 1995.”
The report, Benefits of Rabbit Biocontrol in Australia: An Update, also reveals that the removal of rabbits at a landscape scale is hugely beneficial for the environment — allowing native vegetation to thrive, causing feral cat and fox numbers to plummet and native mammals to bounce back.
Mr Glanznig said while older Australians recalled the devastating ability of rabbits to multiply into plague proportions, people should not lower their guard now there were better controls in place.
“You only have to watch some of the old black and white footage from the 1950s to see how destructive rabbits can be in large numbers,” he said.
“They are absolute eating machines, consuming around 15 per cent of their body weight a day, and costing Australian agriculture around $206 million every year.”
He said Australia’s approach to controlling rabbits was underpinned by science, from the myxoma virus release in 1950 — which killed 99.8 per cent of infected rabbits — to the co-ordinated national releases of two rabbit haemorrhagic disease viruses, with the most recent being in 2017.
“We need to be absolutely tenacious in keeping ahead of the rabbit’s ability to develop genetic resistance, because even small numbers of rabbits can have really negative impacts on native vegetation and animals including 322 nationally threatened species and nine ecological communities,” he said.
“We know that mulga, for instance, are impacted by rabbits with densities as low as one rabbit per 100 hectares — that’s the equivalent of one rabbit per 90 rugby league playing fields.”
Mr Glanznig said long-term scientific monitoring had revealed the release of rabbit haemorrhagic disease viruses was the single most important and cost-effective conservation action for small, threatened mammals and a range of ecosystems.
“This shows that rabbit biocontrol is fundamental to protecting Australia’s globally important wildlife and threatened species, as well as generating benefits to agriculture worth several hundred million dollars every year,” he said.
The centre is now working on the fourth phase of a long-term rabbit biocontrol pipeline strategy.
It will look at potential new biocontrol agents that include genetic biocontrol technologies, more efficient ways to monitor rabbit abundance impacts through new satellite imaging methodologies and the use of artificial intelligence.
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