What Has Disappeared?

Most of the animals that South Australia has lost are vertebrates (animals with backbones), and most of these are terrestrial mammals. South Australia has lost 26 species (25%) of its mammals since 1836, a very high proportion compared with other areas of the world. By contrast, yet only 3 species (1%) of birds, 1 species (2%) of freshwater fish and no reptiles or frogs have become extinct within South Australia.

Invertebrates as well?

One large and easily recognised crayfish species is included in the display, but it is almost certain that other invertebrates (eg. insects, spiders, crustaceans) have also disappeared. The factors leading to invertebrate extinctions are likely to be the same as for the vertebrates.

Reintroductions

Two of these species, the koala and brush-tailed bettong, became extinct in South Australia early this century but have been reintroduced into South Australia, from Victoria and Western Australia, respectively. South Australia's native koalas were restricted to the lower southeast of the state and possibly the Mt Lofty Ranges; thus koalas on Kangaroo Island are actually living outside the natural range of the species at the time of European settlement.