Why are they a pest?
Rabbits are a serious threat to our biodiversity and environment. They ruin beautiful landscapes with rabbit holes, and cause soil erosion and degradation. Ten rabbits can eat as much grass as one sheep, which affects pastoral production. They destroy gardens and eat tree seedlings and veges and they breed like, well, rabbits. Rabbits as young as five months’ old can have up to 50 babies a year and may be pregnant for 70% of a year! Ouch!
What do they look like?
Rabbits are a small mammal, grey-brown or sometimes black in colour. They can be 34-50cm in length and can weigh about 1.1-2.5kgs.
Click here to see images
Where can they be found?
Rabbits prefer grassland habitat at low altitudes, lots of sun and not a lot of rain. That’s why Central Otago is so perfect for them and one of the reasons numbers are so high there.
What are the rules?
- All land occupiers must control rabbits on their land to at/below level 3 on the Modified McLean Scale (MMS 3).
- There are now good neighbour rules for rabbits. If you receive written direction from an Authorised Person you must control rabbits to MMS 3 within 500m of a neighbouring property boundary that is controlling rabbits to MMS 3 also within 500m of the boundary. This is so your hard work doesn’t go to waste if a neighbouring property isn’t doing their part. Good neighbour rules bind all landowners including the Crown.
- To put this simply, if your neighbour has reduced rabbit numbers to MMS 3 within 500m of your shared boundary then you need to be a good neighbour and do the same so efforts are not fruitless.
- You must not discharge a firearm within or across a property before or during a control operation using bait unless under the instruction or supervision of an Authorised Person. This will scare all the rabbits and render the operation mostly ineffective.
Modified McLean Scale
The Modified McLean Scale (MMS) is a scale used by councils to determine rabbit levels. It helps with regulation to make sure landowners are managing rabbit numbers to a level set in the Pest Plan. Otago’s Pest Plan has set the scale for Otago at a maximum of level 3.
As a rule of thumb, if you see groups of rabbit droppings less than 10 metres apart, there’s a problem and you need to take action.
No sign found. No rabbits seen.
Very infrequent sign present. Unlikely to see rabbits.
Pellet heaps spaced 10m or more apart on average. Odd rabbits seen; sign and some pellet heaps showing up.
Pellet heaps spaced between 5m and 10m apart on average. Pockets of rabbits; sign and fresh burrows very noticeable.
Pellet heaps spaced 5m or less apart on average. Infestation spreading out from heavy pockets.
Sign very frequent with pellet heaps often less than 5m apart over the whole area. Rabbits may be seen over the whole area.
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.
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.
How can I control them?
There’s no magic fix, but there are a number of humane methods you can choose from or combine to control rabbits.
- Rabbit-proof fencing
- Habitat change
- Night shooting
- Viruses, these are a short-term fix to reduce rabbit numbers. ORC is responsible for any release of viruses. Other control methods still need to be used.
- Science, e.g. sterilisation via gene-driven technology (still in development).
Rabbit management is more effective in autumn/winter, when rabbit numbers are lowest and they aren’t breeding.
Rabbit-proof netting fence is the best way to protect your land. The mesh size should be no larger than 3cm. The fence height should be at least 1042mm, with a 15cm apron or buried 20cm into the ground.
Regularly maintain your fence and make sure rabbits aren’t burrowing under the bottom.
Cylinders of rabbit netting, plastic netting or sheet steel guards are also useful for protecting young trees or shrubs from rabbits.
Removal of vegetation and other materials that hide rabbits such as wood piles and small shrubs/bushes will make it easier to manage them.
Poison using Pindone rabbit pellets
Poisons are a cost-effective approach for reducing rabbit numbers, and Pindone is ideal for lifestyle and semi-rural properties.
- Poisoning works best in winter but can be carried out at other times of the year
- Work with your neighbours so a wider area is covered and the operation is more effective
- To avoid rabbits becoming bait-shy, leave at least three years between poison operations
- Pindone has a low risk of toxicity to domestic pets (e.g. cats and dogs) but is toxic to birds
- Make sure stock and pets (and children!) don’t have access to the area Pindone has been put out
- Follow the Pindone instructions and safety precautions, use a bait station or seek professional help
Fumigation using Magtoxin
Magtoxin is a solid fumigant and easy to use. Magtoxin tablets react with water vapour from the soil and air, and release a poisonous and flammable gas called hydrogen phosphide. This gas is heavier than air, and flows down the burrow.
- Follow the Magtoxin directions carefully. If used correctly, fumigation will kill all rabbits in a burrow.
- Make sure you follow all safety precautions carefully, including handling and storage instructions
- Be aware of the symptoms of poisoning and the recommended first aid treatment
- Many burrows have more than one entrance so make sure you locate all of them
- We recommend using a dog to hunt the area first, which will help drive the rabbits into the burrow. Make sure the dog is restrained before you start fumigating
- Note that Magtoxin will only work in burrows and is not suitable for rabbits living in piles of rocks or under buildings
- If there are cobwebs over the burrow entrance, it’s probably not being used. We advise blocking the entrance to prevent rabbits using it in the future.
- If you are using Magtoxin in very dry conditions, we recommend scrunching some damp newspaper down the burrow after the fumigant has been applied. This will speed up the generation of the poisonous gas.
- Regular shooting is effective to keep rabbit numbers low
- Note that you cannot shoot a rifle in urban areas and you must hold a firearms licence
- You can use an air rifle without having a firearms licence if you’re over 18 years of age and follow safety precautions
- Check out https://safershooting.co.nz/nz-police/
- We suggest you contact neighbours before carrying out any shooting
- Make sure you positively identify your target before shooting – safety first!
- Shooting is most effective at night, when the sky is overcast and there is little or no wind
- Shine a spotlight within the range of the firearm. Don’t look too far ahead for rabbits as they may move if disturbed by the light.
- Work into the wind where possible
- Return to areas where rabbits may have been missed and, if possible, approach from a different direction
Take note of any holes or warrens so they can be fumigated. Also look for rabbit habitat such as piles of fallen trees or scrub cover so these can be removed. Where possible, fumigate holes while night shooting.
- We recommend trapping as an option only for those with experience in trapping
- The law states you must check traps at least once every 24 hours
- Check with your local council that traps are permitted under by-laws
- Trapping is time-consuming when compared with other methods, but can be useful for lower rabbit numbers
You can purchase rabbit-proof fencing, traps, bait stations, Pindone and Magtoxin at rural supply stores, or you can look online. Care is required with poisons so follow all directions.
Commercial pest controllers
There are some professional pest controllers in Otago who may be able to help you with rabbit management.
Rabbit Haemorrhagic Disease Virus (RHDV) also known as rabbit calicivirus disease was introduced to New Zealand illegally in 1997. Although viruses can provide a good knock back in numbers, they are no silver bullet and ongoing rabbit management is needed to keep numbers down.
In 2018 a controlled release of the RHDV1 K5 (K5) virus around New Zealand, led by the Ministry for Primary Industries (MPI), took place. This is a different strain of RHDV but not a new virus. The K5 virus is only harmful to rabbits and doesn’t affect any other animals. It was hoped that this new strain would provide enough of a knock back for landowners to get on top of rabbit control. Results are still being studied by Landcare Research as the viruses will continue to work into the future.
For more information on the K5 virus, go to:
Click here to see an information sheet on the RHDV1 K5 virus.
The RHDV2 virus has been confirmed in New Zealand. Cases of this have been picked up as part of monitoring the effectiveness of the controlled calicivirus K5 release. Biosecurity New Zealand will continue the surveillance programme to help us understand the new strain's spread.
Steps pet and farmed rabbit owners can take to minimise the risk
There are a number of practical steps rabbit owners can take to minimise the risk to their rabbits of contracting a rabbit virus.
- Controlling insects (especially flies and fleas) as much as possible both indoors and outdoors. Flies are the main vector through which the virus is spread.
- Remove uneaten food on a daily basis as to not attract flies.
- Keep pet rabbits indoors where possible.
- Rabbit-proof backyards to prevent access by wild rabbits.
- Regularly decontaminate equipment and materials (eg. cages, hutches, bowls) with either 10% bleach or 10% sodium hydroxide. Leave for 10 minutes, then rinse off.
- Limit contact with and handling of unfamiliar pet rabbits. Take special precautions if attending any events where unfamiliar rabbits are present, such as petting zoos, rabbit shows and rescue centres.
- Use good biosecurity measures (eg. wash hands, shoes and clothing) after handling other people's rabbits.
- Isolate new rabbits for 7 days before introducing to other rabbits.
- Rinse all leafy greens well before feeding them to rabbits. While feeding rabbits leafy greens remains a risk for introducing rabbit viruses, the benefits of feeding these is considered to outweigh the risks.
The RHDV2 strain is unique from the RHDV1 K5 virus so ensure your pet rabbits have been immunised with the vaccine Filavac to protect them against RHDV2. Please see the information Biosecurity New Zealand have put together regarding:
Authorised Person – for the purposes of our pest plan an authorised person is a warranted officer under the biosecurity act, for example one of our biosecurity officers
Land occupier – An occupier is the person who physically occupies the place, whether they own it or not. For example if you are renting a house owned by someone else that does not live on that property, you are the occupier. You can see more about the responsibilities of occupiers (including owners) in 3.3.1 section 3.3.1 of the pest plan.
Sign – this is referring to rabbit holes, disrupted vege gardens, any evidence of rabbits being present.