The damage feral cats cause to native wildlife was brought home in an image released on social media this week.
University of Sydney researcher Emma Spencer posted the image above on Twitter of a large feral cat with a sand goanna in its mouth.
Ms Spencer, who studies animal carcasses in the wild, said the photo was captured on "CarcassCam" at Bush Heritage Australia's Ethabuka Nature reserve taken in the Simpson Desert, 150km north-west of Bedourie
Ms Spencer said feral cats kill millions of native Australian animals every year and while they typically target small mammals, they may also hunt reptiles in the warmer months.
"Sand goannas are very strong creatures and very fast so they are difficult to kill," she said.
"What it shows is that feral cats are very different from cats in the city and have to be much larger."
Ms Spencer said carcass camera was actually pointed at something and only captured the cat and its prey in the background of the photo.
"There's no doubt the cat killed this goanna," she said.
Feral cats are an enormous problem for wildlife. Across Australia, they collectively kill more than three billion animals per year.
Cats have played a leading role in most of Australia's 34 mammal extinctions since 1788, and are a big reason populations of at least 123 other threatened native species are dropping.
New Australian National University research shows pet cats are wreaking havoc, too.
ANU analysis compiles the results of 66 different studies on pet cats to gauge the impact of Australia's pet cat population on the country's wildlife.
On average each roaming pet cat kills 186 reptiles, birds and mammals per year, most of them native to Australia, the ANU found.