A huge feral cat has been spotted in Australia's Simpson Desert carrying a sand goanna it had just killed.
Researcher Emma Spencer posted an image of the footage of the cat at the Ethabuka Reserve near the Queensland-Northern Territory border. The video was taken on wildlife cameras that have been set up to study decomposing animals in their natural habitat.
Spencer, a PhD researcher for the Global Ecology Lab and the Desert Ecology Group at the University of Sydney, said it was a "bit shocking" to see such a cat with such a large prey.
"Feral cats are captured pretty commonly on our cameras," she said. "It doesn't matter if we're all the way out in the Simpson Desert, in the Snowy Mountains, in Kosciuszko National Park, or in the Blue Mountains, we'll always spot a few cats on our wildlife monitoring cameras.
"This one was a bit unusual. We don't often see cats catching something that large... sand goannas can weigh up to 6kg or so," she said.
She said there was "no doubt" the cat had killed the goanna itself, despite them being notoriously difficult to kill because of their strength and speed.
"They will scavenge for other animals but they do prefer live prey. It's not very common that you'll be walking around and find any dead goannas who have been left behind by another animal so it's very likely that cat has grabbed that goanna while he was trying to escape and surprised him."
The photograph shows the reality of Australia's feral cat problem, with the pests responsible for killing an estimated three billion native animals each year.
Scientists believe feral cats have been directly responsible for the extinction of 34 mammal species since they arrived in Australia 200 years ago. They have also decimated the populations of other species, with at least 123 now threatened with extinction because of feral cats.
Spencer said it was increasingly common to see feral cats reach this kind of size.
"An average house cat might weigh from 3,4 or 5 kilograms, and a lot of feral cats are generally not too much bigger than housecats," she said.
"But I think male feral cats are not desexed so many of them grow into these gigantic cats, some of those can be as big as a small dingo. They are rare. Those can weigh over 7kg, so they can get pretty big."
Spencer's twitter account @EE_Spencer is a fascinating insight into Australian wildlife - and the sometimes gruesome outcomes in the natural habitat.
Apart from feral cats, it also features dingoes, kangaroos, foxes and all manner of native flora and fauna - including decomposing creatures in what she calls "beauty in nature, in all its forms".