In the 19th and 20th centuries, various animals, especially cats and rabbits, were introduced to MacQuarie Island, an Australian-owned island between New Zealand and Antarctica, and they disrupted the local ecosystem of seals, penguins and other birds. When everything else failed, the Australians launched a program to eradicate EVERY mammal on the island except for the seals. Hunters and their traps bagged the last pest in 2011, and when no more were seen over the next three years, the program was declared a success in 2014. My guess is that the Australians are now trying to do something like that on their continent.
Thanks Berosus.