Canterbury rabbit calicivirus release results

Environment Canterbury announced the results of its release programme for the new rabbit haemorrhagic virus disease strain, RHDV1 K5.

Regional Leader Biosecurity Graham Sullivan said the result was in line with expectations, reinforcing the important point made throughout the campaign that this release was just one of the tools in the rabbit control toolbox available to agencies and landowners.

“The new strain has certainly helped us in the control of wild rabbit populations by supplementing more traditional control methods,” he said. “An overall 40% kill rate is in line with what we anticipated when the programme started. However, K5 was never going to be the silver bullet for rabbit control.”

The programme released the virus at 92 sites in Canterbury. Analysis across 400 kilometres and 27 high country stations in the Mackenzie Basin, the area with the largest problem, showed an average reduction rate of 40%.

“This reflects the combined impact of K5, the earlier Czech strain, natural mortality and the traditional control methods we are encouraging farmers to continue,” Mr Sullivan said. “On a property basis, the reduction ranged from zero to 70%.”

In Otago, where there were more than 100 release sites (271 nationally, with Auckland yet to start), the average rate of population decline was about 34%.
"Now that the virus is established, it will continue to spread naturally," Graham Sullivan said. "The programme will continue and we will continue to monitor.

“We have also learned a lot, including about the importance of national coordination and ongoing partnership approaches to rabbit issues.

”A self-perpetuating disease that can control up to 40% of the wild rabbit population is a significant benefit to the community, reducing the cost of control for landowners and ratepayers,” he concluded. “However, we strongly encourage landowners to continue with their traditional control methods – these will always be needed to keep on top of the rabbit problem.”