Otago Regional Council chairman Stephen Woodhead says while the 47% average is higher than forecast in the import application for the RHDV K5 virus, high immunity levels in parts of the province reduced its effectiveness.
Otago Federated Farmers president Simon Davies has had reports from farmers saying they have not seen any evidence the new strain is working.
The virus was released last autumn but Davies said some farmers feel they have gone backwards in the battle to control the pest.
Some owners of farms on which it was released agreed to a council request to delay rabbit control to ensure adequate numbers to aid its spread.
Davies said some farmers have told him their rabbit problem is greater now than before K5 was released.
“They have probably taken a step backwards in terms of numbers.”
Farmers believe the Otago release of the virus was too late, with cool, autumn temperatures making vectors less active.
The other issue was a lack of co-ordinated rabbit control.
The council might need to encourage neighbours or districts to do rabbit control at the same time to maximise the impact.
“I don’t want a return to the rabbit board scenario but they targeted areas and co-ordinated control programmes.”
There are now three rabbit virus strains active in Otago but farmers are confused about which strain is working, Davies said.
The Czech strain was introduced illegally in 1997, the K5 strain was released last year and a strain initially found at Blenheim is also present.
Woodhead says it is unclear how the Blenheim one will affect the K5 and Czech strains’ mortality rates but farmers have an obligation to control pests on their land.
“We all know that if you can see rabbits on your property you have a problem.
“It is your duty as a landowner to deal with that problem and put in place effective controls.”
That means using multiple tools such as poison, shooting and biological controls.
