Australia Might Genetically Modify Feral Cats Out of Existence

Australia may use genetic technology to wipe out its six million feral cats. By introducing "genetic biocontrol options," the country could help save its native wildlife and eradicate the invasive species, which causes widespread destruction to the landscape.

Feral cats in Australia are a huge problem. They are second only to European rabbits in threatening the native species. It is estimated feral cats and foxes have killed off 25 native mammal species in Australia, and they—along with rabbits, feral pigs and a plant pathogen—put 800 threatened species at risk.

Every year, feral cats in Australia kill over 530 million native frogs and reptiles, 450 million mammals and 270 million birds.

In 2015, the Australian government announced plans to kill two million feral cats by 2020. Techniques included baiting, shooting and poisoning. One plan even saw the government airdrop poisoned sausages into regions known to have large populations of feral cats.

Despite these efforts, feral cats continue to wreak havoc on Australia's native species. In a report published by government science agency CSIRO, experts have laid out a pathway to managing invasive animals that are threatening wildlife.

Andy Sheppard, CSIRO scientist and co-author of the report, said urgent and coordinated action is needed to stop the spread of invasive species. "Prevention will be much cheaper and more effective than trying to control the spread of pests and weeds once they are established," he said in a statement. "We need to safely harness emerging technologies, revitalize our biosecurity research and innovation (R&I) system and continue to invest in long-term, strategic research and development."

One of the technologies highlighted in the report is genetic control. This, the report says, has "great potential to stop new invaders."

feral cat
A feral cat in Australia. A report by CSIRO says genetic biocontrol could be used to exterminate invasive species. Andrew Cooke

Genetic control as a means of controlling invasive species has been highlighted in recent years in scientific papers. This could involve introducing genes that make a pest more susceptible to disease. Another method involves introducing large numbers of sterile individuals into the population to suppress reproduction.

It is also possible to alter a species' genes so it only produces one sex, meaning it can no longer reproduce. It is this technique that is flagged in the CSIRO report: "Genetic biocontrol options, such as causing all offspring in invasive populations to be only one sex, could dramatically change the fight to control widespread pests, such as carp, cane toads, rodents, rabbits and potentially feral cats," the report said. "'Daughterless carp' was the first, but advances in gene technology promise quicker, easier, more cost-effective ways to control pests at large scales."

Australia currently has the highest rate of mammal extinctions in the world. Climate change and extreme weather events are helping spread invasive species. Feral cats, the report said, will target land recently cleared by fires—prey, such as pygmy possums, have nowhere to hide.

Andreas Ganzing, co-author of the report, said all Australians must work together to prevent further spread of invasive species. "Together we can work to drive down Australia's native species extinction rate—currently over four species a decade—towards net-zero extinctions," he said in a statement.

"The technology exists to establish a national, coordinated community surveillance network, making it possible for everyone to get involved, to help find new invaders early before they can become a problem."