Rabbit
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Rabbit.
Common name:
Rabbit
Scientific name:
Oryctolagus cuniculus
Regional classification:
Service delivery, cost recovery and community control
Description
History
Rabbits were first released in New Zealand by Captain Cook in 1777, and settlers introduced more to provide food, fur, and sport. By the 1870s they were well established.
Habitat
They prefer lighter soils in open country, among scrub in rocky places and plantations. They thrive on land with less than 1000mm of rain per year, sunny aspect, light soil, good drainage and shelter within easy reach of short grass and open ground.
Rabbits live in colonies or warrens, which can be extensive with many interconnecting burrows. They are nocturnal, spending most of the daylight hours below ground.
Rabbits tend to use a communal latrine or mound (pill heap) to deposit their faeces and urine; these along with scratchings define their territories.
Breeding
Under ideal conditions a female rabbit can produce 30 young a year. Rabbits breed throughout the year, although the main breeding season is spring to early summer. The gestation period is 28-30 days and the litter size is 3-7. The doe usually mates again within 12 hours of giving birth.
Why are they a problem?
Ten to 15 rabbits eat as much grass as a sheep. Wild rabbits also sour pasture by eating out the best grass, and their digging can expose vulnerable sand pasture to wind erosion and invasive weeds. They permanently damage seedling trees and are a nuisance in vegetable gardens.
What can I do?
You can use:
REPELLENTS
Repellents are sprayed, painted or rubbed onto young trees. If used correctly, they will deter rabbits from browsing on new plantings. The most common repellents are:
- Egg bases with acrylic paints
- Mutton fat with kerosene
- Thiropel (commercial repellent sold as Thiram)
- Fish fertiliser
Repellents are generally used in pine plantations, horticulture, landscape plantings and gardens. Fish fertiliser and mutton fat are not recommended for broadleaf species as burning may result.
Egg based repellents
To make one litre, suitable for treating 50 seedlings: Mix 80g whole egg powder and 800ml water in 150ml of primal AC235 acrylic resin. Alternatively mix five fresh eggs and 600ml water in the 150ml of resin. Acrylic resin is available from paint stores. Spray about 20ml of the egg based repellent on and around each seedling in the field immediately after planting. Further applications may be needed after heavy rain or in the spring.
Mutton fat and kerosene
Mix one part kerosene and 10 parts melted mutton fat. Allow to set. The repellent is applied by wiping seedlings with a lightly greased rubber glove, leaving minimal visible fat. Dab the ground at the base of the tree and any supporting stakes to provide more smell deterrent.
Thiram
Available from most stock and station agents and used as per instructions. A reapplication will be necessary after heavy rain to maintain effectiveness.
Fish fertiliser
When spread around the base of a tree, fish fertiliser will help to deter rabbits.
FENCING
Fencing provides an alternative to repellents which work on a short term basis only, and poisoning which will not guarantee a100% kill. They will also protect trees against hares which are very difficult to poison.
Pest-proof fencing can protect horticultural blocks growing high value crops. Or plant nurseries where hares or rabbits are liable to cause damage.
Netting fences
A netting fence with mesh no more than 4-5cm in diameter should be at least one metre high and must be pegged or stretched tightly along the ground.
- Ensure there are no gaps under the fence.
- Gates into the block must be tightly fitting and covered with netting, with a timber or concrete sill underneath to ensure gaps are not large enough to let the animal gain access. Gates must be closed at all times.
Timber or corrugated iron fences
Timber paling fences approximately one metre high, with gaps between palings of less than 5cm, or corrugated iron fences, are suitable for small areas. There must be no holes at ground level.
Electric fences
Electric fencing works more effectively using a mains energiser. If using a portable energiser, check regularly that the batteries are still fully charged. Ensure vegetation under the fence is kept down to eliminate shorting.
The lower four wires on the fence should alternate between hot and earthed wires. Each wire should be 8-10cm apart and the first should be 8-10cm out from the base of the fence. Alternatively, electric rabbit netting is available from stock and station agents.
PROTECTIVE DEVICES
Protective devices which can be used for individual plants include:
- 50-200 litre drums, with the tops and bottoms removed
- A wire netting tube which should be staked with wire or wooden pegs to stop it being knocked over
- Heavy clear plastic sheeting about 75cm-1m high, placed around the plant and held firmly by three to four stakes
- Sarlon wind break material placed around the plant and pegged tightly to the ground.
HABITAT CHANGE
A detrimental change to rabbit habitat will have a more permanent effect on numbers than control methods such as poisoning, tapping or shooting. Removal of vegetation or other materials that hide rabbits makes control work easier. If pasture is improved and grazing pressure decreased, grass will be kept long, wet and green, and this encourages debilitating diseases and keeps rabbits wet and cold which increases the mortality of young rabbits. Even though more may be born, less will survive.
Recommended control methods
Night shooting
A successful night shoot can reduce the rabbit population by about 30% with two or three shoots necessary to gain good control. It is important that all areas are covered effectively. Missed rabbits become wary of a spotlight or the sound of a gun.
You must have a licence before using a firearm. Use a gun with extreme care, especially where there are likely to be people or animals in the vicinity.
Poisoning
Rabbit poisons can affect all warm-blooded animals including humans. Read the instructions carefully before use.
Poisoning is the most cost-effective method of controlling rabbits. Poison is most effective from March to September, outside the main breeding season. At this time of year it is likely that young will survive in burrows and re-infest an area.
Pindone
Pindone is an anticoagulant which uses the same principle as rat poisons. A poisons licence is not required to use pindone, which may be laid around buildings and residential areas if treated with the same caution as rat poison. Keep away from children and pets.
Find out more about anticoagulant poisons
Phosphorus
Rabbit strength phosphorus is available to people with a phosphorus poisons licence. It is a very effective if used correctly. It is illegal to use phosphorus poison within 400m of a city or town boundary. It is also illegal to place it within 60m of a public road or place, or any catchment area where water is drawn for human consumption. In these cases only pindone can be legally used.
1080
This poison is available for use only by Regional Councils and the Department of Conservation.
Trapping
Rabbits can be caught in leg hold traps, but these should be used only by experienced people where there is no chance that domestic animals and pets will be caught.
Fumigation
Magtoxin is available as a small tablet which releases the toxic gas phosphine when exposed to moisture. Phosphine is a colourless gas with a garlic odour.
Typically 2-3 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 can be used to make the Magtoxin react if the soil is dry. Phosphine is heavier than air and will flow down the burrow. Fumigation is a good follow-up method to shooting or poisoning and will kill young rabbits which would otherwise be missed and survive.
Magtoxin is available from the Northland Regional Council or from farm supplies outlets.
Find out more: Download rabbit control publication
More information
For further information or control advice please contact one of our Biosecurity Officers at the Northland Regional Council on 0800 002 004:
- Whangarei: Carl Cooper and Steve Henderson
- Dargaville: Paul Ralph
- Kaitaia: Mike Knight