Inside Australiaâs War on Invasive Species The island country has a long history of unique efforts to battle nonnative animals
By Erin Biba on June 9, 2017
The Australian government unleashed a strain of a hemorrhagic disease virus into the wild earlier this year, hoping to curb the growth of the continentâs rabbit population. This move might sound barbaric, but the government estimates that the animalsâbrought by British colonizers in the late 18th centuryâgnaw through about $1150 million in crops every year. And the rabbits are not the only problem. For more than a century Australians have battled waves of intrusive species with many desperate measuresâincluding introducing nonnative predatorsâto limited avail.
Australia is not the only country with invasive creatures. But given that it is an isolated continent, most of its wildlife is endemic, and its top predators are long extinct. This affords alien species a greater opportunity to thrive. âIn other places, youâll see a much bigger predator community,â says Euan Ritchie, an ecologist and one of the directors of the Ecological Society of Australia. But the Tasmanian tiger, the marsupial lion and the Megalania (a 1,300-pound lizard) are gone. The only remaining top predator, the Australian wild dog, or dingo, is under threat from humans because of its predilection for eating sheep.
Along with rabbits, Australia is trying to fend off red foxes (imported for hunting), feral cats (once kept as pets), carp (brought in for fish farms) and even camels (used for traversing the desert). Wildlife officials have attempted to fight these invaders by releasing viruses, spreading poisons, building thousands of miles of fences and sometimes hunting them from helicopters. In one famous case, the attempted solution became its own problem: the cane toad was introduced in 1935 to prey on beetles that devour sugarcane. But this proved a spectacular failure because the toads could not climb cane plants to reach the insects and are now a thriving pest species.
Despite scientistsâ protestations, the government plans to introduce another virus later this year, this time to try reducing the out-of-control carp population. âWe canât go back to the pastâ in terms of returning to the native ecosystem, Ritchie says. So why bother trying? Because, he says, the invaders have not managed to wipe out all the species that are uniquely Australian: âWe have a lot of native mammals and other species that are holding on.â