page_title: Fauna of Australia
section_title: Invasive species
hierarchical_section_title: Fauna of Australia / Invasive species
context_page_description: The fauna of Australia consists of a huge variety of animals; some 83% of mammals, 89% of reptiles, 90% of fish and insects and 93% of amphibians that inhabit the continent are endemic to Australia. This high level of endemism can be attributed to the continent's long geographic isolation, tectonic stability, and the effects of an unusual pattern of climate change on the soil and flora over geological time. A unique feature of Australia's fauna is the relative scarcity of native placental mammals. Consequently, the marsupials – a group of mammals that raise their young in a pouch, including the macropods, possums and dasyuromorphs – occupy many of the ecological niches placental animals occupy elsewhere in the world. Australia is home to two of the five known extant species of monotremes and has numerous venomous species, which include the platypus, spiders, scorpions, octopus, jellyfish, molluscs, stonefish, and stingrays. Uniquely, Australia has more venomous than non-venomous species of snakes.
  The settlement of Australia by Indigenous Australians between 48,000 and 70,000 years ago, and by Europeans from 1788, has significantly affected the fauna.
context_section_description: Introduction of exotic fauna in Australia by design, accident and natural processes has led to a considerable number of invasive, feral and pest species which have flourished and now impact the environment adversely. Introduced organisms affect the environment in a number of ways. Rabbits render land economically useless by eating everything. Red foxes affect local endemic fauna by predation while the cane toad poisons the predators by being eaten. The invasive species include birds (Indian mynah) and fish (common carp), insects (red imported fire ant) and molluscs (Asian mussel). The problem is compounded by invasive exotic flora as well as introduced diseases, fungi and parasites.
  Costly, laborious and time-consuming efforts at control of these species has met with little success and this continues to be a major problem area in the conservation of Australia's biodiversity.
  Many of the introduced species are not regulated through wildlife services and can be regularly hunted year round.
caption: The poisonous cane toad
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