Bye bye bunny: introduction of a new calicivirus aims to target wild rabbit population growth cause by resistance to previous virus strains. Photo: Melissa Adams ACT Parks and Conservation will introduce a new strain of calicivirus next week and expects to wipe out 20 to 40 per cent of wild rabbit population.
The Korean strain of Rabbit Haemorrhagic Disease Virus, known as RHDV1 K5, is part of the national rollout at more than 600 sites.
Local authorities will introduce the virus at Namadgi National Park and on land adjacent to Mulligans Flat Nature Reserve by luring wild rabbits through free feeding sessions and then offering virus-laden carrots as bait.
ACT Parks and Conservation director Daniel Iglesias said rabbits were agriculture’s most costly pest animal and the nationally coordinated biocontrol strategy would be a helping hand for landholders.
“Rabbits are a serious environmental pest as their grazing results in a loss of vegetation and their warrens contribute to soil erosion,” he said. “Rabbits compete with native wildlife for food and their grazing limits the ability of plants to regenerate.”
The new variant of the fast-moving virus was more humane as it killed rabbits more quickly than prior forms, but it was safer too.
Research had shown RHDV1 K5 only affected the European rabbit and could not harm other animals, even those that ate affected rabbit carcasses.
Vertebrate pest officer Oliver Orgill said more than 50 per cent of the ACT Parks and Conservation pest control budget, approximately $150,000, was spent on managing wild rabbit population growth annually.
“That is just on the Parks and Conservation estate, not picking up what private landholder and farmers are doing,” he said.
Mr Orgill said the virus release was one of a suite of tools used to suppress pest population growth and would be used in concert with other methods such as poisoning and the fumigation and destruction of warrens.
“They really are ‘s number one pest species and unfortunately we are going to have rabbits forever in , we are not going to get rid of them,” he said.
“We are going to need to come up with tools and techniques to keep rabbit populations suppressed to a low level to avoid those impacts to agricultural and environmental areas.”
He said mortality rates would not be as extreme as when the first calicivirus was released two decades ago, and as the carcasses were no risk to other species, a clean up plan was not necessary.
Owners of domestic rabbits have been able to protect their pets with a RHDV1 vaccine since 1996 and Mr Orgill said existing vaccination was effective against the new strain too.
n Veterinary Association president, Dr Robert Johnson said extra precautions such as insect-proofing hutches, washing hands between handling rabbits and avoiding feeding cut grass to pet rabbits could all reduce the risk of contamination.