The native plants and animals of Australia have adapted to life on an isolated continent over millions of years. Particularly since European settlement our native animals have had to compete with a range of introduced animals for food, shelter and the area they live in. Some of our native species have also had to face new predators. Such rapid change has also had a major effect on our soil and waterways.

Feral animals in Australia are either domestic animals that have gone wild or those that were introduced for pest control or for recreational use. Feral animals causing most public concern include: rabbits, foxes, cats, pigs, goats, donkeys, camels, water buffalo, mosquito fish, the northern Pacific seastar (Asterias amurensis) and cane toads.

In Australia feral animals have few natural predators or fatal diseases and some have high reproductive rates. As a result, their populations can multiply rapidly if conditions are favourable. Drought is the main factor in controlling their populations. Numbers will drop quickly when food and water are limited.

Some feral animals prey on native animals and compete with native animals for food and shelter, and the area they live in. Some feral animals may also compete with livestock for food. They can also cause damage to the land and waterways used by our native animals and our farmers.

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: http://www.environment.gov.au/bg/wildlife/invasive/feralintro.html

This site also makes it clear that in the control of feral pests, animals must be treated humanely.

Methods of control that use other living things (such as natural predators, parasites, disease carrying bacteria or viruses) as tools to control the pests are, by definition, biotechnology. They are usually called 'biological control'. A new approach to biological control reduces the fertility of the pests by suppressing fertilisation so that fewer young are produced. This is called 'immunocontraception'.