Our environment is our most important asset. We work with the community to ensure the sustainable use of our natural resources. The future of our beautiful region starts with protecting and caring for it today.
We work with the community to promote the sustainable management of natural physical resources. The Resource Management Act sets out how we should manage our environment and forms the foundation for the majority of our work.
Feral rabbits (Oryctolagus cuniculus) are small mammalian herbivores that inhabit grasslands at low altitudes across the Otago region. They were introduced to New Zealand in the early 1800s for meat and hunting, but in the absence of predators they have become a significant pest in Otago. Rabbits are a serious threat to our biodiversity, environment, and economy. They graze native seedlings and vegetation, compete with stock for pasture and crops, and cause soil erosion and degradation.
Rabbits reproduce rapidly. Females can be pregnant for 70% of the year and are capable of adjusting their litter size according to food supply, so rabbit populations are capable of rebounding quickly from natural disasters or control pressures. Rabbits as young as five months old can produce up to 50 offspring each year.
There is also good neighbour rules for rabbits. If you are controlling feral rabbit levels to at or below MMS 3 within 500m of your property boundary, then your neighbours must do the same if they receive written direction from an Authorised Person. 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 (e.g. Department of Conservation, Land Information New Zealand).
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.
The Modified McLean Scale (MMS) is a scale used by councils to determine rabbit population levels through examining rabbit sign . It helps with regulation to make sure landowners are managing rabbit numbers to a level set in the Regional Pest Management Plan. Otago’s Regional Pest Management 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.
Scale
Rabbit infestation
1
No sign found. No rabbits seen.
2
Very infrequent sign present. Unlikely to see rabbits.
3
Pellet heaps spaced 10m or more apart on average. Odd rabbits seen; sign and some pellet heaps showing up.
4
Pellet heaps spaced between 5m and 10m apart on average. Pockets of rabbits; sign and fresh burrows very noticeable.
5
Pellet heaps spaced 5m or less apart on average. Infestation spreading out from heavy pockets.
6
Sign very frequent with pellet heaps often less than 5m apart over the whole area. Rabbits may be seen over the whole area.
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.
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.
Table: Modified McLean Scale (Credit: National Pest Control Agencies).
How can I control them?
Rabbit management needs to be coordinated and ongoing. Control options need to be tailored to the size, type, and location of a property. Depending on the severity of the rabbit problem on a property, you may need to engage a professional contractor. A good contractor will advise which type of control would be most effective on a property, when to carry out control, and discuss any other factors that may impact the result e.g. property rabbit fencing.
We strongly recommend that you develop a long-term plan for managing rabbits on your property, to maintain rabbit numbers at low levels, rather than reacting only when numbers reach crisis levels.
Ongoing monitoring will help you to assess the effectiveness of any control methods used and will also help to detect and address any future rise in rabbit numbers before they become a problem again.
Fencing your property can be expensive, but it is an effective way to protect your land and to maximise the effectiveness of any control work that you undertake. To be effective, a rabbit fence should:
be at least 600 - 900mm high (the higher the better)
be made from galvanised wire netting (plastic can be eaten through)
have a mesh size no larger than around 40mm
have the bottom of the fence buried at least 150mm into the ground or bent as an apron and pegged/stoned in the direction that the rabbits will attempt to enter
be regularly checked for signs of rabbits climbing, digging or making holes and repaired/maintained accordingly
Gates should be kept closed when not in use, preferably with a concrete sill under them to prevent rabbits from squeezing their way underneath.
Alternatively, rabbit netting can also be used to prevent rabbit movement under or around the gate.
Cylinders of rabbit netting, plastic netting or sheet steel guards are also useful for protecting young trees or shrubs from rabbits.
Primary control
Primary control is used as an initial knock-down for rabbit numbers. Primary control can reduce rabbit numbers significantly but will never eradicate the population completely, and if the remaining rabbits are not addressed then rabbit numbers will bounce back.
The most common form of primary control is poisoning.
An effective rabbit poison is the anticoagulant, Pindone. This is available in bait form as liquid Pindone, usually laced carrots, or Pindone pellets. The optimum time to use Pindone poison is in winter, as this is when food sources are most scarce and fewer young rabbits are present due to other mortality factors. Like most anticoagulants, Pindone is slow acting and requires the rabbit to consume baits over several days to be effective, with this in mind it is considered to be a humane poison.
It's always best to ensure that no domestic stock or pets have access to the areas being treated. It is, therefore, essential to plan stock movements in advance to accommodate the intended poisoning operation. An effective antidote (Vitamin K1, phytomenadione) is available from veterinarians either as an injection or as a tablet, if required.
Warning signs must be erected at all access points to the areas being treated and ideally you will be undertaking control work in collaboration with your neighbours but if not, you should notify all adjacent land occupiers (and any others who may have access to the area) of your intention to undertake a poison operation.
Caution: When using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.
Pindone carrot
Liquid Pindone laced carrots generally work best during winter months. As liquid Pindone laced carrot cannot be stored for long periods of time, planning of anticipated operations needs to be conveyed to contractors well in advance to ensure sufficient carrot is available from growers.
Pindone carrot baiting must be undertaken by the holder of an Approved Use for Pindone Certificate and/or Controlled Substance License (CSL).
Pindone pellets
Pindone pellets are readily available, store quite well and are ideally used when natural feed conditions are dry (e.g. summer). They can be dispensed in bait stations by anyone, provided they follow the manufacturer’s instructions. Pindone pellets can also be broadcasted outside of bait stations – however this can only be undertaken by the holder of an Approved Use for Pindone Certificate and/or Controlled Substance License (CSL).
Please note results can be variable when broadcasting pellets outside of bait stations if the environmental conditions are unsuitable (e.g. ground moisture can be absorbed by the pellets making them less palatable).
While bait stations may have an advantage of not requiring a CSL, rabbits are generally cautious about feeding from them as they are neophobic.
Watch the video below to learn more about using pindone pellets in bait stations.
Secondary control measures can be used as a follow up to primary control to help address the last remaining rabbits, or as an on-going maintenance tool to keep rabbit numbers low. It is important to note that installing and maintaining a good rabbit fence (including a rabbit netted gate), will maximise the effectiveness of any control work that you undertake by reducing reinvasion from adjacent areas.
The most common secondary control methods are listed below, and more information about each is given in the following subsections:
Habitat modification
Fumigation
Night shooting
Other secondary control methods include ripping / burrow destruction, trapping, ferreting, long netting and dogging.
An ideal habitat for rabbits is easily found on a lot of properties like gardens and lawns with short grass, garden sheds, wood piles or dense vegetation that provide cover.
Habitat changes to make your land less desirable for rabbits can have a more permanent impact on rabbit numbers than other methods such as poisoning.
You can do this by:
removing any piles of wood, rubbish or vegetation that offer rabbits protection from the weather and predators
pruning the bottom of shrubs and hedges so they don’t provide a suitable shelter for rabbits
ensuring that any gaps under buildings and sheds are blocked to prevent rabbits from gaining access
Fumigation is best used to control medium to low density populations or in conjunction with other methods such as a follow-up after a poison operation.
To effectively fumigate a rabbit warren, you need to be able to identify and seal off all entrances. This may require a coordinated approach across multiple properties and as with any poison operation you should try to coordinate with your neighbours if you are going to undertake work.
Fumigation can be carried out at any time of year, but it has the greatest long-term effect if carried out before the rabbit breeding season (late winter to early summer).
Fumigants are toxins used to kill rabbits in their burrows. When a fumigant is introduced to a burrow system it produces toxic fumes, which are inhaled by the rabbit’s causing death by absorption through the lungs.
The main advantage with using fumigants is that the operator does not have to rely on the rabbit eating bait. It is also a very effective method of controlling young rabbits which don’t wander far from their burrows.
Fumigation using Magtoxin
The most common fumigant used to control rabbits is Magtoxin. Magtoxin is a solid fumigant that reacts with water vapour from the soil and air to release a toxic and flammable gas called hydrogen phosphide. This gas is heavier than air and flows through the burrow.
Engaging a professional contractor is recommended, however anybody can purchase up to 3kg of Magtoxin from rural supply stores and carry out the work themselves without needing a Controlled Substance Licence (CSL). If you are planning to undertake the work yourself, please note the following: :
PLEASE READ THE LABEL THOROUGHLY to ensure that all safety precautions, and handling and storage instructions are followed carefully.
Magtoxin is only effective for burrows or warrens and is not suitable for rabbits living in piles of rocks or under buildings
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
Advise your neighbours if you are intending to carry out a toxin operation
Watch the video to learn more about using fumigation (magtoxin).
Shooting is an effective method of controlling low rabbit infestations. Shooting to control medium or high rabbit numbers has limited effect on the population level and may result in surviving rabbits becoming more wary. Poisoning is a more appropriate and cost-effective method for controlling medium to high levels of rabbits.
Shooting is ideally used as a secondary control method after a poisoning operation to address remaining rabbits (i.e. mop up survivors), and as an on-going maintenance tool to keep rabbit numbers low.
Engaging a professional contractor to do this work is recommended, but if you are undertaking the work yourself, please note the following:
You must hold a firearms licence
You cannot shoot a rifle in urban areas. Shooting can only be carried out in urban areas by a certified contractor.
You can use an air rifle without having a firearms licence if you’re over 18 years of age and follow safety precautions
Contact neighbours before carrying out any shooting
Make sure you positively identify your target before shooting
Shooting is most effective at night, when the sky is overcast and there is little or no wind
Return to areas where rabbits may have been missed and, if possible, approach from a different direction
Working with contractors for effective rabbit control
You can employ an individual or a business to undertake or support you with rabbit control on your property. Having a reliable contractor with the right skills and equipment is important for effective control; and having some knowledge yourself of how to manage rabbits and what to expect from a good management plan will give you better results.
We recommended that you ask your neighbours, other nearby landowners, local biodiversity groups or farming groups for their suggestions.
Alternatively, if you are interested in more information about rabbit contractors working in your area, please contact us on 0800 474 082 or at pests@orc.govt.nz and we can email you a current list.
A good contractor should be able to discuss options for permanently reducing rabbit numbers (i.e. long-term control) rather than just focussing on immediate gains (i.e. short-term control). A good contractor will also be able to answer the following:
What is their experience? Have they undertaken programmes in the local area before?
Are they authorised to use chemicals e.g. do they hold a Controlled Substance Licence?
Do they have protective clothing and equipment?
Can they direct you to previous clients who will vouch for their work?
It is recommended if hiring a contractor, you encourage them to conduct a site inspection to obtain an accurate quote.
Your contractor may ask:
What your short and long term goals are
Where and what is the damage
Location of rabbit feeding areas
Location of burrows
Location of rabbit habitat
Whether the neighbours have feral rabbits
Rabbit numbers: small or large population
What treatment you would like to use on your property
Whether there are any methods that you are opposed to
Where you want them to work on your property
An indication of budget available
Location and type of wildlife on your property – such as native birds, stock or pets
If you’re unable to provide this information, recommend the contractor inspects the site. If they don’t ask at least some of these questions, it is worth seeking additional quotes.
At a minimum, the contractor should be able to outline:
A method for primary treatment to provide an initial knockdown of rabbits (e.g. Pindone carrot)
They should also be able to inform you about:
Methods for follow-up secondary treatment to address any rabbits left behind after the primary treatment
Likely success of any treatment methods discussed
Realistic expectations in the absence of good fencing (if applicable)
The contractor may also outline how to assess changes in active burrows, rabbit abundance, plant germination and recovery, night counts, and before-and-after photos.
You will see evidence of active rabbit behaviour such as fresh new scratchings (freshly turned soil), fresh droppings (black and shiny), reopened or new burrows created, vegetation attacked, and crops grazed. In time, more burrows will be reopened or dug.
Community-led rabbit management programmes
The aim of these programmes is to support communities to develop and maintain a strategic long-term management approach to rabbit control rather than a reactive one-off control approach.
To achieve this, the focus is on facilitating a coordinated community approach and educating community about the benefits of implementing a strategic approach, starting with a primary control operation followed by implementing ongoing secondary control methods.
This approach is more likely to result in a long-term reduction in rabbit numbers and sustained control.
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, ongoing rabbit management is still needed to keep numbers low.
In 2018, a controlled release of the RHDV1 K5 virus around New Zealand took place, led by the Ministry for Primary Industries (MPI). The effectiveness of the virus on feral rabbit populations is still being studied by Manaaki Whenua - Landcare Research. The RHDV1 K5 virus is only harmful to rabbits and doesn’t affect any other animals.
The RHDV2 virus has been confirmed in New Zealand. Cases of this have been picked up as part of monitoring for the controlled RHDV1 K5 release. Biosecurity New Zealand will continue the surveillance programme to help understand the new strain's spread.
The Otago Regional Pest Management Plan 2019-2029 (RPMP) identifies feral rabbits as a pest animal to be managed under a sustained control programme. To implement a sustained control programme, and monitor the efficacy of this programme, ORC currently undertakes night count and day inspection monitoring. Opportunity for improvement to the programme and monitoring methodologies was identified in 2021. In addition, the establishment and facilitation of community rabbit programmes, to address rabbit management in peri-urban and urban areas, requires revision of current monitoring methodologies to be fit for purpose for smaller property areas.
ORC commissioned two external reviews of the current ORC rabbit monitoring methodologies and tools and invited recommendations for improvement and development. These recommendations were synthesised alongside staff feedback and used to develop an action plan for night count and rabbit density monitoring; inspection and night count monitoring analysis; virology and serology; proneness and climate change; networking and engagement; and strategy and management. Implementation of this action plan is underway.
Authorised Person – under the Biosecurity Act 1993 an Authorised Person is authorised to administer and enforce the provisions of the Act, for example an ORC Biosecurity Officer.
Land occupier – an occupier includes a 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 section 3.3.1 of the Regional Pest Management Plan 2019-2029.
Neophobic – neophobia is the fear of anything new.
Sign – any evidence of rabbits being present, such as burrows, scratchings or scat.
