“Australia is one of the most important nations on Earth for biodiversity. In fact, Australia is one of only 17 ‘megadiverse’ nations and is home to more species than any other developed country. Most of Australia’s wildlife is found nowhere else in the world, making its conservation even more important. 87% of our mammal species, 93% of reptiles, 94% of frogs, and 45% of our bird species are found only in Australia.
Sadly, however, Australia is facing an extinction crisis. Australia has the worst mammal extinction rate in the world: 29 native mammals have become extinct since European settlement. To put this in a global context, 1 out of 3 mammal extinctions in the last 400 years have occurred in Australia.
More than 1,700 species of animals and plants are listed by the Australian Government as being at risk of extinction. Nearly 1 in 4 of our mammal species and around 1 in 7 of our bird species are listed as threatened. The primary factors causing this loss of wildlife include:
- Feral cats and foxes. For example, feral cats kill an estimated 75 million native animals every night across Australia.
- Feral herbivores including pigs, goats, rabbits, donkeys, horses, camels, buffalo, and feral cattle.
- Changes in fire regimes, especially an increase in the extent and severity of wildfires.
- Clearing native vegetation.
- Weeds. (Source)
“The researchers found that 11 percent of the 273 land mammal species endemic to Australia have gone extinct since European settlement and another 21 percent are considered threatened. By comparison, just one North American native land mammal became extinct since European settlement — the sea mink, which was overhunted. Worldwide, around 1.5 percent of 5,500 mammal species are extinct. The scientists noted that seven species that were once widespread on the Australian mainland now live naturally only on islands that the cats and foxes have yet to colonize. They also discovered that unlike the rest of the world, where larger mammals are at the highest risk of extinction, the Australian mammals being killed off are small — perfectly ‘meal-sized’ for their predators” (source).
For more on the subject, see the Proceedings of the National Academy of Sciences’ article, “Ongoing unraveling of a continental fauna: Decline and extinction of Australian mammals since European settlement” by John C. Z. Woinarski, et al., doi: 10.1073/pnas.1417301112.
