Methods to control feral pests
Pest Animal Control Cooperative Research Centre
Many of the traditional methods used to remove or control these feral pests are not biotechnological methods. 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 in the control of feral pests, animals must be treated humanely.
The RSPCA is also concerned with the humane treatment of feral animals. You can read about their policies at www.rspca.org.au.
Read about invasive species in Australia at the Department of Environment and Heritage: http://www.deh.gov.au/biodiversity/invasive/index.html
Read about what pest animals are found in Australia and the various control programs being researched at the Cooperative Research Centre for Pest Animal Control: www.pestanimal.crc.org.au
Search a database of information on vertebrate invasive animals in Australia and New Zealand through the National Feral Animal Control Program: www.feral.org.au
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, and the method is 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 find a natural predator for this organism and introduce it 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 chemicals such as 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, and the predator can sometimes 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 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 there must be extensive research carried out on its biology and its potential effects on Australian ecosystems. 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.
Fertility control
A new biological control method aims to reduce the fertility of the pests by suppressing fertilisation to produce fewer young. This is called 'immunocontraception'. The scientists developing this technology take seriously issues such as the risk of exporting an immunocontraceptive virus in live animals, and risks to non-target species both here and in other countries.
It is unlikely that biotechnology will provide a magic bullet solution for feral animal control. Usually a biotechnology solution will have to be used in combination with other control methods mentioned above.
Introduced pests in Australia - work sheet [PDF 50kb | 3pages]
Should we interfere with nature? - work sheet [PDF 51kb | 2 pages]