Rabbit-killing virus set for release

People with pet rabbits are being warned to make sure the animals are vaccinated ahead of a controlled release of the rabbit-killing calicivirus in the Far North this month.


Mike Knight, a Kaitaia-based Pest Management Officer with the Northland Regional Council (NRC), says the virus occurs naturally among wild rabbits in Asia and Europe but was originally introduced into New Zealand illegally in 1997.


Its use has now been legalised subject to strict conditions. (The NRC is a member of a consortium of 10 Regional Councils and two Unitary Authorities which several years ago gained approval to import the virus from Australia and register it in New Zealand as a ‘’rabbit biocide”.)


Mr Knight says calicivirus is already widespread in Northland, but as it is “host-specific” it targets only adult rabbits and poses no risk to humans or other animals.


“Rabbits die from the disease in Northland every year, however, pockets of low or nil infection are still thought to exist here.”


The Council last released the virus in Northland in mid-2006, a move which had successfully reduced populations in some areas, however, rabbit numbers had since built up again in different locations, prompting plans for a new release.


He says the virus is typically released into areas bordering urban centres, with a high public use or a high habitat value where normal rabbit control methods like shooting or poison can’t be used.


“At this stage, we’re currently assessing areas where medium to heavy infestations have been reported to determine where the virus will be released, but it looks likely that there will be three main releases in the Ahipara, Taupo Bay and Kerikeri areas.”


Only qualified Regional Council staff and licensed operators will be involved in the releases, which typically cut rabbit populations by 40 to 60 percent.


However, Mr Knight says it’s important that people with pet rabbits and/or those who breed the animals contact their vet to arrange to have them vaccinated ahead of the release.


“The vaccination costs about $30 and should protect the rabbit for life.”


He says the baits used as part of the campaign are diced carrots laced with a solution containing the virus.


“These operations are typically done during winter to target core rabbit populations as with less food around, it’s more likely the animals will take the infected baits.”


Mr Knight says at this time of year there are also fewer younger rabbits about, which is important as the Council is keen to avoid exposing those less than 12 weeks old to the virus.


“This is because very young rabbits are more likely to catch the disease and survive, which then gives them an immunity which they’ll keep for the rest of their lives.”


Mr Knight says the first releases of the virus are scheduled for the week beginning Monday, 26 July.