A photo of a feral cat with a goanna in its jaws has been discovered accidentally by researchers.
The image shows the feline carrying a sand goanna through the northern Simpson Desert at Ethabuka Reserve near the Queensland-Northern Territory border.
It was taken inadvertently by wildlife cameras being used to study decomposing animal carcasses.
University of Sydney researcher Emma Spencer said it was a stroke of luck.
"The cat with a goanna in its mouth was actually in the background," she said.
"The large cat was walking behind one of our carcass cameras and we just happened to catch him with a great big sand goanna in its mouth."
Researchers are using cameras to investigate what happens to animal carcasses that result from roadkill, drought and bushfires across the country.
The feral cat with its goanna meal was photographed in 2018 but was only discovered during the course of the research this month.
Ms Spencer said while cats generally fed on birds and mice, they also scavenged larger animals such as kangaroos.
"This goanna could weigh up to six kilograms, that's quite large prey for a cat," she said.
"But I definitely say that a cat that size would be very capable of taking out a sand goanna.
"Though it is surprising, it is definitely possible that cat caught that goanna itself."
Biosecurity says it's not unusual
While the image is striking, Biosecurity Queensland principal scientist Matthew Gentle said it was not an unusual sight.
"We've seen similar photos through our research of cats dragging back killed wallabies … to feed offspring," he said.
"Certainly we know the impact of cats and how devastating they can be."
A report co-authored by Biosecurity Queensland estimates there are as many as 5.6 million feral cats across 99.8 per cent of the country.
Mr Gentle said cats often took reptiles, birds, mammals, insects, fish and amphibians.
"We certainly know that cats are excellent predators," he said.
"A lot of our native species they can readily catch and consume."
He said it was up to everyone to take reasonable steps to minimise the risk of invasive species, including through local government biosecurity plans.
