19. Australia Ends Up Overrun With Rabbits
Rabbits, which are not native to Australia, did not face as wide and lethal a variety of predators to keep their population in check Down Under as was the case in their native habitats. So from cute and cuddly and sometimes delicious animals, they morphed in Australia into feral and invasive pests that devastated much of their new home. As early as the 1820s, settlers were complaining of rabbits overrunning the place. By the 1860s, between the disappearance of many natural predators, mild seasons allowing for year-round breeding, and natural selection producing a hardier breed of wild rabbits, their population exploded.
By 1920, there were an estimated 10 billion feral rabbits hopping around Australia. They competed with livestock for pasture, ate crops, and stripped the soil of vegetation. The latter is particularly problematic, as Australia has the most vulnerable soil and the one most susceptible to erosion of all the continents, except for Antarctica. For over a century, Australia has struggled to control its rabbit population, with measures that included shooting, poisoning, and infecting the pests with epidemic diseases. The most conspicuous measure, though was and remains fencing, ranging from fences around individual farms and pastures, to massive fences stretching for hundreds of miles, such as Western Australia’s Rabbit-Proof Fence. The latter failed to live up to its name: rabbits jumped over and burrowed beneath it.