Keep rabbits from damaging high value biodiversity sites.
|Production threat||Environmental threat||Public threat|
Rabbits have been a major agricultural and environmental pest in parts of New Zealand since the 1870s. While rabbits are now widespread throughout the Waikato region, in most locations they are no more than a nuisance factor as the region’s high rainfall and lush growth restricts their abundance. However, periodic infestations can be found around the sandy pumice soils south of Tokoroa and Lake Taupō (particularly the Western Bays), along the narrow strip of land either side of the Waikato River as far north as Rangiriri, and in the coastal communities of the Coromandel.
Uncontrolled rabbit populations can expand rapidly in the holiday areas of Coromandel and Taupō as many properties are not occupied year round. Holiday home owners should consider rabbit control as a regular part of their property management.
The European rabbit was introduced to New Zealand as a food source and hunting resource in the 1830s. Females can produce 45 to 50 young each year, but only about 10 per cent of juveniles survive to six months of age.
In large numbers, rabbits compete for grazing, reducing the amount of palatable pasture and farm stocking capacity. They contribute to erosion and undermine buildings with their burrowing and affect dune restoration and native restoration programmes. They damage young plantation trees, horticultural crops and residential and vegetable gardens and lawns.
All landowners/occupiers in the Waikato are responsible for controlling rabbits on their properties. If Waikato Regional Council receives a valid complaint about rabbits, it uses the modified McLean scale to check how bad the infestation is (see table on next page). Any property monitored at level 5 and over will be a problem for neighbouring landowners and the land occupier will be directed to control rabbits until they are at level 4 or below.
Waikato Regional Council can supply technical advice if needed and/or pest contractor contact information.
Rabbits’ burrows can be identified by the small ‘heap’ of soil at their openings. Other signs of rabbits include damage to pasture and plants. However, it’s difficult to be sure whether this damage has been caused by rabbits, unless you’ve seen them regularly and found their pellets or droppings in those areas where they’ve been spotted.
Rabbits leave droppings in small heaps or scattered throughout their feeding areas. The droppings are generally dark in colour, oval-shaped and approximately 8 to 10mm in length.
The McLean scale below is used by councils to assess levels of infestation in relation to the number of ‘heaps’ visible in an area.
As mentioned earlier in this factsheet, any property monitored by the council at level 5 and over will be a problem for neighbouring landowners and the landowner/occupier will be directed to control rabbits until they are at level 4 or below.
The European rabbit is about the size of a small domestic cat, with long ears and a small tail. They breed continually throughout the year, with adult females capable of producing 45 to 50 young each year.
|1||No sign seen. No rabbits seen.|
|2||Very infrequent sign present. Unlikely to see rabbits.|
|3||Sign infrequent with heaps more than 10m apart. Odd rabbit may be seen.|
|4||Sign frequent with some heaps more than 5m butless than 10m apart. Groups of rabbits may be seen.|
|5||Sign very frequent with heaps less than 5m apart inpockets. Rabbits spreading.|
|6||Sign very frequent with heaps often less than 5mapart over the whole area. Rabbits may be seen over the whole area.|
|7||Sign very frequent with 2-3 heaps often less than 5m over the whole area. Rabbits may be seen in large numbers over the whole area.|
|8||Sign very frequent with 3 or more heaps often less than 5m apart over the whole area. Rabbits are likely to be seen in large numbers over the whole area.|
Note: This scale provides an index of rabbit density that is most useful when making comparisons between similar types of country, or recording changes from year to year in the same district. It is not suitable for measuring short term changes because old signs may last and numbers seen are affected by factors like the time of day and pasture length. The McLean scale level 4 indicates a minor-moderate infestation density. Any property monitored at level 5 and over represents a situation where rabbits on the assessed property are likely to be impacting on neighbouring landowners and control action is required.
Disclaimer: Any product names mentioned below are not an endorsement nor are they a criticism of similar products not mentioned.
Repellents are designed to make plants unattractive to browsing rabbits. They are generally applied as sprays, which have to be reapplied periodically to treat new growth within browsing range (40 to 50cm above ground level). Spray-on repellent solutions should not be applied to the point of run off as with other garden sprays. Adhesives in repellent mixes can block plant stomata, especially on delicate foliage when heavy applications are used.
The following commercial preparations are available through many garden centres and agricultural merchants:
If using repellents on a small scale, the following ‘homebrew’ options can also be considered.
|Egg mix||Thiram mix|
100mL water-based paint
Mix eggs and paint, then add water. Pour through strainer into spray applicator. This mix does not last as well as commercial egg preparations and usually has to be reapplied every three weeks.
|50g thiram fungicide
100ml water-based paint
Mix thiram powder with a little water to make a paste, then add the rest of the water and the paint. Thiram provides good protection but remember, it is an agrichemical. Follow all label instructions regarding use and handling.
Without suitable habitat, rabbits become exposed to the elements and are easy prey for their predators. If gullies are cleaned up, weeds (gorse and blackberry) controlled and logs and other rubbish removed, rabbit numbers can be considerably reduced. Also, ensure that access under baches, support buildings and sheds is blocked using the same techniques as with exclusion fences. Prune shrubs and hedges and remove other vegetation that offers rabbits protection from the weather and predators.
Habitat manipulation has a more permanent effect on rabbit numbers than other control methods.
Fencing can protect gardens and specific crops. To be effective, a rabbit-proof fence should be at least 80cm in height and made from galvanised wire netting with a maximum mesh size of 3cm. As rabbits can dig under fences, the bottom of the netting should be buried 20cm into the ground or turned out along the top of the ground in the direction that the rabbits will attempt to enter. Gates through the fence must be close fitting, preferably with a concrete sill under them to prevent rabbits from burrowing underneath.
Individual shrubs and trees can be protected using rabbit netting cylinders, plastic sheaths or steel guards. Electric fencing can also prevent rabbits from damaging crops and gardens.
Integrate a variety of control methods for a better effect than only one control method.
Shooting can be effective in controlling light infestations of rabbits and is probably the most common form of rabbit control in New Zealand. Every person who is shooting must either hold a firearms licence, or be under the supervision of a person who holds a firearms licence. You should inform your neighbours of where and when you intend to be shooting.
When night shooting, ensure your spotlight battery is fully charged and you know the area well. Make sure you positively identify your target before shooting. For example, the ‘eye-shine’ of rabbits and possums is red-pink, while the ‘eye-shine’ of sheep and cattle is yellow-green. Note that repeated night shooting in the same area may become less effective, as rabbits can become shy of light and guns.
Trapping can be time consuming, requires knowledge of correct trap placement to prevent catching other animals and is not recommended unless you already have some trapping experience.
If you live in an urban area, there is a real risk of catching someone’s domestic animal. Check with your local district/city council to ensure that traps or snares are allowed under local bylaws. Contact your local biosecurity animal pest contractor for more information on using traps for rabbit control. See the More information section on the back page for details.
Pindone™ can be purchased for use in bait stations from your local agricultural store. Please note, you cannot use pindone outside a bait station (for example, laying baits on open ground) unless you have a controlled substance licence.
Pindone is an anticoagulant poison originally developed for rodent control. Rabbits are particularly susceptible to pindone, while cats and dogs are five to six times more resistant and humans 100 times more resistant. This makes pindone, when used correctly, relatively safe for use in urban areas. Follow the manufacturer’s instructions and keep bait containers in cool and dry locked cupboards.
Pindone is slow acting and the rabbit must consume baits over several days for it to be effective. Accidentally poisoned domestic pets should be taken to a vet who will administer Vitamin K1, an effective antidote.
Pindone must be used in a bait station that:
Examples of suitable bait stations include the NoPest Multifeeder bait station and modified Philproof bait station. These bait stations are also suitable for possums, rodents and ferrets. For information on where to buy them, see the Commercial pest controllers section of this factsheet.
For large numbers of rabbits, increase the number of bait stations and spread them through areas containing rabbit signs. For help with correct bait station placement, contact the biosecurity team at the council. Rabbits are ‘neophobic’, meaning they don’t like new things. It may take time before they take pindone from the bait station. Be patient and don’t tamper with the placement of the bait station.
Rabbits do not always live in burrows. Sometimes they live under buildings or in patches of heavy cover. However, rabbits in a burrow can be controlled by fumigation.
A fumigant introduced to a burrow system produces toxic fumes. It is also very effective for controlling young rabbits that do not wander far from their burrows and are difficult to poison or shoot. Magtoxin is recommended for general use. It produces phosphine gas.
Fumigation is labour intensive and is best used in conjunction with night shooting or as a follow up to poisoning. Use a dog to run the area first, which helps drive rabbits into cover underground. Make sure the dog is restrained before you start fumigating.
Burrows often have more than one opening so check the surrounding area for other possible entrances. Next, using the spade or grubber, cut back the opening of the burrow so you have easy access. Cut a sod of earth the appropriate size to completely block the entrance.
Before using any fumigant or poison:
Place the fumigant at least 30 to 40cm into the burrow. Ensure that any escaping fumes are blown away from you by the wind.
Immediately seal the burrow by placing the sod of earth grass side down (this prevents loose soil from falling onto the fumigant and burying it) into the entrance and stamping it in to make the burrow as air tight as possible. Systematically fumigate all burrow entrances. If you are using Magtoxin in very dry conditions, place the fumigant on a piece of damp paper or cloth already placed down the burrow.
To kill a trapped rabbit, approach from behind and grasp it by the back legs. Stun the animal by quickly delivering a sharp blow with a hammer or heavy stick to the head, between and slightly forward of the ears. Apply a second hard blow to the same area of the head to kill the rabbit.
Dispose of rabbit carcasses by burying them in your garden, leaving them for the hawks or to decompose at the edge of a paddock, or putting them in your rubbish bag if you live in an urban area.
|Control method||Key points|
|Repellents||Effective to allow plants to grow above height of rabbit browse.Short lived effects.Doesn’t affect rabbit population.|
|Habitat manipulation||Long term effects.
Can be costly.
|Shooting||Requires a firearms licence.
Only effective on low to moderate rabbit numbers.
Can’t be used in residential areas.
|Trapping||Risk of catching domestic animals.Must be checked daily.Caught rabbits must be dispatched.|
|Poison – Pindone™||Bait stations must be used unless pindone is used by a controlledsubstance licence holder.
Effective when available feed is scarce and rabbit warrens can’t be located.
Can take weeks before rabbits start to consume bait.
|Magtoxin||Highly effective when rabbit warrens are obvious.
Controls young rabbits yet to venture out of warren.
Pest control contractors can be found under pest control in the Yellow Pages. Some companies are included in the list below on where to buy rabbit control products and services.
Try your local farm supply stores or garden centres or contact: