Invasive plants and animals
Why some species are unwelcome
Hundreds of extinctions have been caused by invasive alien species. The ecological cost is the irretrievable loss of native species and ecosystems.
IUCN, the International Union for Conservation of Nature, states that the impacts of invasive species are immense, insidious and usually irreversible. They may be as damaging to native species and ecosystems on a global scale as the loss and degradation of habitats.
For example, European red foxes introduced into Australia have taken a toll on many native species, including small and medium-sized rodents and marsupials.
Growing global trade and communication is directly contributing to the mixing of wildlife across bio-geographical boundaries.
Growing realisation of the ecological costs of invasion
Some species that appear in new environments die, while others thrive and become invasive. In many cases, native species are likely to be unprepared to defend themselves against the invaders. This process, together with habitat destruction, has been a major cause of native species extinction throughout the world in the past few hundred years.
In the past, many of these losses have gone unrecorded. Today, there is a growing realisation of the ecological costs of biological invasion in terms of the native biodiversity losses.
Countering the invaders
Biologists are investigating how these invaders succeed in establishing themselves in new environments so that, where necessary, the intruders can be controlled and eradicated.
Click here to read more about Rats and Cats.
Garden Escapees & Cane toads
Go to our Cane Toad page (archived)
Escaped invasive garden plants are the biggest source of agricultural and environmental weeds, costing farmers many millions of dollars each year.
Go to our Garden escapees page (archived)