Imported into Australia in the mid-nineteenth century, rabbits have overrun much of the country, causing extensive agricultural and environmental damage and demonstrating the dangers of introducing non-native species into an area. Before the first humans arrived in Australia, the only mammals living there were about 150 species of marsupials as well as bats, rats, mice, platypuses, and echidnas. The chief predator in Australia today is the dingo, a wild dog introduced about 40,000 years ago by Australia's first human settlers, the Aborigines. When the British settled Australia as a penal colony in the late 1700s, they brought a variety of pets and livestock with them, including rabbits.

The problems with rabbits began in 1859, when 12 pairs of European rabbits were released on a ranch. Since no significant numbers of natural predators were present in Australia, the rabbit population exploded within a few years. They overgrazed the grass...