What does it look like?
Rabbits are usually grey-brown in colour, with other colour varieties occasionally occurring in the wild. They may live in communal warrens (underground tunnels with multiple entrances) or above-ground where sufficient cover exists. Rabbits prefer habitats with free draining soils and open grassland with adjacent taller vegetation, as well as scrub for cover.
Why is it a problem?
Rabbits breed rapidly and populations can recover quickly after being reduced by disease, control pressures or environmental changes. They are a significant agricultural and ecological pest eating a variety of plant matter including grasses seedlings of trees and crops. Rabbits compete directly with stock for grazing and can sour pasture by eating out the most palatable species of grass. This can be a serious problem for native plant regeneration and farm or lifestyle block owners. They also increase the risk of soil erosion.
Rabbits can breed rapidly. Females may be pregnant for 70% of a year and can produce a total of 20 – 50 young each. They are also capable of adjusting litter sizes to food supply, so rabbit populations are capable of rebounding quickly from natural disasters or control pressures. Some wild rabbits may live up to seven years, but life spans are generally much shorter.
The Modified McLean Scale is used to assess rabbit infestations in New Zealand. Plan Rule 17 in the Hawke’s Bay Regional Pest Management Plan states that “an occupier of land shall maintain rabbit populations at or below level 4 of the Modified McLean Scale from mid-January to mid-August over any part of their land”.
The Modified McLean Scale:
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1 |
No sign found. No rabbits seen. |
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2 |
Very infrequent sign present. Unlikely to see rabbits. |
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3 |
Pellet heaps spaced 10m or more apart on average. Odd rabbits seen; sign and some pellet heaps showing up |
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4 |
Pellet heaps spaced between 5m and 10m apart on average. Pockets of rabbits; sign and fresh burrows very noticeable |
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5 |
Pellet heaps spaced 5m or less apart on average. Infestation spreading out from heavy pockets |
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6 |
Sign very frequent with 2-3 pellet heaps often less than 5m apart over the whole area. Rabbits may be seen over the whole area |
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7 |
Sign very frequent with 2-3 pellet heaps often less than 5m apart over the whole area. Rabbits may be seen in large numbers over the whole area |
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8 |
Sign very frequent with 3 or more pellet heaps often less than 5m apart over the whole area. Rabbits likely to be seen in large numbers over the whole area |
Control methods
Fumigation and ripping are good follow-up methods to shooting or poisoning and will kill young rabbits that may otherwise survive. Cleaning up rubbish/slash and burn piles as well as removing harbour such as gorse, broom, blackberry and thistles and other areas rabbits frequent, shelter or hide in will help reduce suitable habitat. Exclusion fencing can be effective where other methods are not able to be employed.
Prevention
Spray or paint chemical repellents on trees and shrubs to discourage rabbit browsing. Start this when the tree is first planted and continue as the plant grows and weathers.
Stopping rabbits from accessing your property or garden is the best long-term method of control in urban areas. Exclusion fences need to be at least 80cm high, 20cm in the ground with a maximum mesh size of 3 cm. Trees can be protected with netting cylinders, plastic sheaths or steel guards.
Shooting
Control rabbits in rural areas by shooting at night with a spotlight and a .22 rifle or shotgun. You must follow all legal and safety requirements for firearms. A successful night shoot can reduce a rabbit population by about 30 percent with two or three shoots necessary to gain good control. It is important to effectively cover all areas as any rabbits that have been missed become wary of a spotlight or the sound of a gun and vehicle.
CAUTION: A VALID NEW ZEALAND FIREARM LICENSE IS REQUIRED UNDER NEW ZEALAND LAW FOR ANY USE OF FIREARMS
Pesticide control
Poisoning is the most cost-effective method of controlling rabbits. Poison is most effective from March to September when there is less food available and outside the main breeding season, when the young are likely to survive in burrows and re-infest an area.
Rabbit poisons can affect all warm-blooded animals including humans. Pindone is a slow-acting anti-coagulant poison which uses the same principle as rat poisons. Rabbits are particularly susceptible to this product. It is available as pellets or a liquid concentrate which is applied to oats or cut carrot. Liquid Pindone is restricted to those certified for its use.
Pindone pellets must be used in bait stations unless you have an Approved Handler Certification. Use Pindone pellets in bait stations in areas where rabbits have been grazing and scratching. Stations may be placed around buildings and residential areas if treated with the same caution as rat poison. Keep away from children and pets and follow label directions. Bait stations such as the NoPests® Multi-Feeder pipe can be closed during the day or during wet periods to prevent bird interference and bait getting wet.
Biocontrol
Three variations of the rabbit haemorrhagic calicivirus (RHDV1, RHDV1 K5 and RHDV2) are known to be in New Zealand and have controlled wild rabbit populations to varying degrees. The virus spreads between rabbits and a rabbit dies quickly once it begins to show symptoms. The virus only affects rabbits and hares, and does not affect cats, dogs or any other animals.
A variation of the virus was released in 2018 as New Zealand's feral rabbits had become increasingly immune to the RHDV1 strain. This was released on private land or in some areas where there is minimal public access. Find more information about this virus from Landcare Research and Ministry for Primary Industries.
Contact your local vet to vaccinate pet rabbits for protection from the RHD virus: pet rabbits should be vaccinated from 10 weeks of age, and boosters given according to your vet's recommendation.
Warren destruction
Ripping and collapsing large warrens is an effective method that takes away the rabbits ability to produce large numbers of offspring. Effective ripping of warrens relies on deep ripping with close ripping lines and the ripping extending past the warren. Ideally, the ripper tines should be to a depth of 900 mm, at a spacing of 500 mm. After ripping one way it should be repeated at 90° — this process is known as cross-ripping.
Particular equipment may be useful for particular jobs. To protect native vegetation, a single ripper tine on a front-end loader or a backhoe can do the trick. Blade ploughs may be adequate for light or loamy soils, and disc cultivators may be successful in cultivated areas where rabbit numbers are low.
Fumigation
Magfume© (formally known as Magtoxin) is available as a small tablet which releases toxic phosphine gas when exposed to moisture. Phosphine is a colourless gas with a garlic smell.
Typically, 4-6 tablets down a rabbit burrow will be enough to kill any animals in it. When fumigating, make sure all burrow entrances are blocked. A small amount of water or damp material can be applied (prior) to make the tablets react if the soil is dry.
More information
Free on-site Advisory Service
To receive a free consultation for recommended rabbit control options tailored to your property, contact our biosecurity team on 06 835 9200.
Related links
For detailed information on how to manage rabbits, download the Rabbit Control Options PDF
Management Programme
Sustained Control Programme
To provide for ongoing control of the subject, or an organism being spread by the subject, to reduce its impacts on values and spread to other properties.
Rules
Plan rule 17
Except where an occupier of land has entered into an active Written Management Agreement approved by Hawke’s Bay Regional Council, and upon receipt of a written direction from an Authorised Person, an occupier of land shall maintain rabbit populations at or below level 4 of the Modified McLean Scale from mid-January to mid-August, over any part of their land.
Taxonomies
FamilyLeporidae
TypeAnimals
GroupMammal
HabitatLand
Management ProgrammeSustained Control Programme
RulesPlan rule 17
