In 1859 when Thomas Austin released 24 wild rabbits on his Geelong property, he could not have foreseen that they would breed so prolifically and spread across the southern parts of the continent. Each year rabbits cause an estimated $600 million worth of damage to agriculture. They also cause serious erosion problems, prevent native vegetation from regenerating, attack domestic gardens and undermine farm sheds and other buildings.
In WA European rabbits (Oryctolagus cuniculus) are declared pests of agriculture under the Biosecurity and Agriculture Management Act 2007 and as such, landholders are required to control rabbits on their properties. Even landholders not growing crops are still legally obliged to control rabbits to protect their neighbours’ land from the impact of rabbits.
Checking rabbit activity
Areas intended for seeding, planting or conservation efforts, especially near rabbit harbourage, should be thoroughly checked. This is particularly important in areas where rabbits have previously been a problem. Rabbit activity is usually indicated by scratchings, dung heaps and active burrows or warrens. More revealing checks can be made late in the day or at night by spotlighting when rabbits are active and more observable.
- The key to success is persistence. One-off efforts produce only short-term results as rabbits may produce many offspring and populations can recover quickly even after successful control programs.
- Maximum effectiveness is achieved by integrating appropriate control methods. Best control is achieved in late summer when rabbit numbers are decreasing and feed is limited.
- District-wide campaigns can reduce the problem of re-infestation by covering a large area.
- Sometimes it will not be possible to use poison but other methods are available (for example, fumigation, ripping.)
A summary table of available control options is provided at the end of this article. Information is also available from the Centre for Invasive Species Solutions pestSMART website.
Baiting is the most cost-effective way to reduce rabbit populations, particularly over large areas, but restrictions do apply.
Several types of 1080 (sodium fluoroacetate) rabbit bait is available. Trained landholders can purchase bait products after they have obtained Baiting Approval from an authorised officer of the Department of Primary Industries and Regional Development (DPIRD). 1080 is quickly broken down in the environment. Many native animals have developed a high degree of tolerance to 1080. Domestic stock and pets are however very sensitive to the poison in both baits and poisoned rabbits.
Pindone is an anticoagulant with an effect similar to products used in some rat poisons. It can sometimes be used near settlements where pets might be at risk from 1080, because unlike 1080, an antidote is available for pindone.
However, pindone poses a risk to native animals including kangaroos, birds of prey and perhaps bandicoots. The poison must not be used in the presence of these animals.
Rabbits use warrens as refuges and for breeding. Fumigation is the best method to use when a few rabbits live in widely scattered warrens or inaccessible areas. Warrens are treated with aluminium phosphide tablets which liberate phosphine gas on exposure to atmospheric or soil moisture.
Please refer to the WA Department of Health website for public health requirements as the Health (Pesticides) Regulations 2011 (Pesticide Regulations) require that risk assessment, fumigation plan and emergency managment plan be completed and implement prior to using fumigants in WA.
Areas where warrens have been destroyed by cross-ripping the soil are much less likely to be recolonised by rabbits. A tractor-mounted ripper is used to penetrate the soil to a depth of at least 60cm.
Areas that rabbits use for harbourage/refuge include rock piles, deadfall timber and stumps, old buildings and abandoned farm machinery. Such material should be removed, buried or surrounded with rabbit-proof fences. Permission will usually be required before remnant or roadside vegetation can be cleared.