You are not permitted to download, save or email this image. Visit image gallery to purchase the image.
Wet and warm springs and summers are keeping rabbit numbers down across Canterbury.
Environment Canterbury biosecurity team leader Brent Glentworth said for the past two seasons warm, wet weather during the first rabbit breeding cycle had been largely responsible for keeping the population in check.
Young rabbits had a low survival rate in those conditions because they succumbed to pneumonia or coccidiosis - a liver disease ''very prevalent'' in warm, wet weather, Mr Glentworth said.
The rabbit breeding season began about August and the young born then could have their first litters as early as November.
But if there was high mortality early in the season, then there were fewer rabbits from those litters to go on to breed, he said.
Rabbit numbers were still of concern in the semiarid, ''rabbit-prone soils'' around the Haldon Rd, on the eastern side of the Mackenzie Basin. More than 10,000ha was affected across five large-scale high country blocks. Runholders were working together and making steady progress with primary poisoning.
Further control work was planned for this winter.
Immunity to rabbit haemorrhagic disease (RHD) had been increasing since 2005, prompting farmers to use traditional control methods - contract shooters and patch poisoning.
''We can't afford to keep the pressure off.
''We're looking at 70% immunity across the region. Immunity is continuing to increase but at a lower rate - it's flattening out.''
It was having its greatest effect in coastal areas where there could be a noticeable increase in young rabbits in spring, then around autumn they ''disappeared'' because of the disease, Mr Glentworth said.