Methods to control feral pests

Feral pests: fox and pig

Pest Animal Control Cooperative Research Centre

Many of the traditional methods used to remove or control feral pests do not use biotechnology. Such methods include fencing, trapping, poisoning and shooting.

You can investigate the practicality, effectiveness, cost and effect on other species of each of these methods at a number of websites. These feral animal websites make it clear that animals must be treated humanely during control of feral pests.

Biological control

Methods of control that use other living things such as natural predators, insects, parasites, disease carrying bacteria or viruses are, by definition, biotechnology. These methods are described as biological control.

Natural predators & diseases

An introduced organism often becomes established because it has no natural predators in its new environment. To control the pest biologically, we can introduce one of its natural predators into the environment where the animal or plant is a pest.

Ideally, using a specific predator means that we do not need to rely on chemical pesticides or other methods that may harm the ecosystem. However, care is needed, because introduced species are among the biggest causes of extinction of native plants and animals. Sometimes, the predator can do more harm than good.

In Australia, biological control has often been used successfully, including the introduction of a beetle to control prickly pear and a weevil to control water hyacinth. But one application of this form of biological control - the cane toad - went very wrong.

The cane toad was introduced into Queensland in 1935 to eat a pest beetle that was ruining sugar cane crops. However, the cane toad failed to control the beetle and instead thrived in the warm climate.

The cane toad has now spread widely through northern Australia, devastating populations of native species and changing the ecology of areas well beyond the borders of Queensland. It has even reached Kakadu National Park – a World Heritage Area in the Northern Territory, where it has the potential to do tremendous damage.

Before any new organism can be introduced, its biology and potential effects on Australian ecosystems must be extensively researched. This may take several years. Other precautions include the strict controls that the Australian Quarantine and Inspection Service (AQIS) applies to help prevent the unauthorised introduction of new organisms into Australia. These steps are designed to avoid a repeat of the cane toad episode.

However, we cannot always predict how new species will interact in a complex and open system such as the environment.

It is unlikely that biotechnology will provide a magic bullet solution for feral animal control. Usually, a biotechnology solution would have to be used in combination with other control methods mentioned above.

Introduced pests in Australia - work sheet [PDF 33kb | 3pages]

Should we interfere with nature? - work sheet [PDF 30kb | 2 pages]