In the past 200 years, since the arrival of Europeans in Australia, 18 of the continent's mammal species have become extinct. These extinctions have been chiefly attributed to introduced, non-native predators, especially foxes and cats. Johnson et al. present evidence that the success of these medium-sized introduced predators has been the direct result of persecution by humans of Australia's native large predator, the dingo. In areas where dingoes have been left alone, foxes and cat populations are kept at bay, and the diversity and abundance of native marsupials are greater. Thus, top predators can maintain biodiversity at middle trophic levels and may help ecosystems to resist invasion by alien species. By allowing dingo populations to recover in regions where they have been persecuted, it might be possible to insure remaining small marsupials against further decline and extinction. -- AMS
Proc. R. Soc. London Ser. B 10.1098/rspb.2006.3711 (2006)
