Property owners need to get tough on controlling rabbits on their properties, especially around Taupo and along the Waikato River, according to Environment Waikato.
The Regional Council says rabbits are grazing pasture, reducing ground cover and pasture carrying capacity in these areas where they are in large numbers on sandy, pumice soils. They add to soil erosion by burrowing and removing ground cover, damage seedlings and cause damage in urban gardens.
Because they breed continually throughout the year, females can produce 45 to 50 young each year. They tolerate a wide range of climates, and prefer close-cropped pasture, scrub cover and areas where there are few predators such as cats and ferrets.
Landowners are responsible for rabbit control under the Regional Pest Management Strategy. The aim is to reduce populations to acceptable levels, and Environment Waikato will monitor land infested with rabbits on complaints from neighbours with a common boundary.
Landowners can discourage infestation by reducing warren sites and habitat such as logs and blackberry patches. Crops and gardens can be protected with rabbit-proof fencing and repellents can be used around the base of seedling trees to discourage browsing.
Rabbits are repelled with mix of egg yolk and resin or using chemical repellent. Burrows can be fumigated, and rabbits can be poisoned with pindone, trapped or shot.
Rabbit Calicivirus can also be used as a biological control. Rabbit Haemorragic Disease (RCD) appears to spread in cyclical patterns, with pockets of rabbits showing signs of resistance. Long-term resistance does not seem to be established in the Waikato.
Landowners wanting more advice can call Environment Waikato's Freephone 0800 800 401.