Australia's threatened species
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Even though many species in Australia have become extinct since European settlement, there are also success stories such as the successful propagation of the Wollemi pine.
When Captain Cook was exploring the east coast of Australia, he had with him a very talented young botanist, Joseph Banks. Banks quickly realised that he was observing thousands of plant species that were obviously unique. He and Cook went home excited by all the different plants and animals they had seen during the expedition. Soon the whole of Europe was talking and speculating about the strange flora and fauna of Terra Australis.
Since then hundreds of species have become extinct in Australia, including at least 50 bird and mammal species and more than 60 plant species. It is likely that other species have disappeared too, without our knowledge (Box 1: The hidden species at risk).
Biologists have now listed all those plants and animals that they know are at risk of extinction in Australia. These are called endangered species. The list includes 19 species of fish, 16 frogs, 16 reptiles, 47 birds, 39 mammals and 612 plants. In addition, there are many more species that are listed as vulnerable and some that are classified as rare.
What threatens the continuation of species?
There are two main threats to the continuation of species in Australia, and these threats have already caused extinctions. They are:
- loss of habitat this may result from climate change, activities of humans or natural events;
- the introduction of alien species which prey on and compete with native species for food and habitat (Box 2: The aliens).
Land-clearing and the spread of towns and cities have destroyed many habitats. Fertilisers such as superphosphate have encouraged introduced pasture species at the expense of native grasses and the animals that feed on them.
Conditions in many parts of Australia have always been harsh. Our flora and fauna have lived through droughts, fire and flood and they have done this largely by surviving in refuge pockets where conditions are less severe than in other places. But, with European settlement many refuges were destroyed and, in those that remained, feral animals also moved in and killed, or competed with, native species.
Why does extinction matter?
A certain level of biodiversity (biological diversity) is necessary to keep our ecosystems healthy. This is because each species performs a different function within an ecosystem. For example, some species allow pollination to occur, some recycle nutrients, some maintain soil fertility. Species interact with each other and rely on each other. One species may be a source of food for another, or may help keep another's population in check.
As well as allowing natural ecosystems to function in a healthy manner, biodiversity is important for other reasons (Box 3: Australia's biodiversity). Extinction has always occurred; the important thing today is that the rate has greatly accelerated. This increased rate of extinction has already led to unstable ecosystems as well as to the loss of potentially useful species. For instance plants provide us with all of our food (directly or indirectly), as well as one-quarter of our medicines. The potential of many plants to supply food, medicines or other commodities remains unexplored. And what other useful compounds could exist in unknown plants?
Can we prevent extinctions?
If we are aware of the problem and are concerned for our unique plants and animals, there is a good chance that we will, at least, slow the rate at which organisms are becoming extinct. And there are some success stories to encourage us:
- The humpback whale population is beginning to grow since the whale has been protected from exploitation.
- The bilby (one of our most highly endangered mammals) is being reintroduced to places where it once used to flourish.
- In Victoria, great efforts are being made to conserve the long-footed potoroo a small kangaroo-like species that was not discovered until the late 1970s, and which is threatened because its habitat is being destroyed by logging.
- Efforts have been made to secure a reserve system in Australia that protects an adequate and representative sample of forest habitats and, therefore, of biodiversity (Box 4: The mathematics of reserve systems).
However, not all species under threat of extinction are being protected, nor is there sufficient funding to do so. Deciding how to allocate funds for threatened species programs is a difficult problem (Box 5: Survival of the cutest).
Who in government is responsible for protecting our threatened species?
The Australian Government Department ofDepartment of Sustainability, Environment, Water, Population and Communities is responsible for environmental policy issues. Within that department, the National Strategy for the Conservation of Australia's Biological Diversity is responsible for running programs aimed at protecting threatened species in Australia.
Related Academy Material
Interviews with Australian Scientists
Dr Hugh Tyndale-Biscoe (Marsupial biology)
Page updated January 2012.