What drove the Tasmanian devil out of northern WA?

Tasmanian devils are not an animal ordinarily thought of in connection with the remote north of Western Australia.

But a new study suggests the marsupial may have played an important clean-up role for people in the Pilbara before being driven out by the arrival of the dingo.

Palaeontologist Tim Churchill said the devil specimens were among thousands of animal bones and rare artefacts uncovered during ongoing excavations at Juukan Gorge, about 1500 kilometres north west of Perth. 

"There are two very clear specimens of the Tasmanian devil, one dating from the Holocene at around 7,000 years ago," Dr Churchill, from the University of New South Wales, said.

"The other dating to before the last glacial maximum at around 43 to 47,000 years old."

The new research also showed the devils were visiting Juukan Gorge rock shelters frequently.

"We found lots of evidence of bones that have been chewed and digested by devils, which suggests that devils were accessing carrion that was accumulated by humans," Dr Churchill said.

The bones were found in the same area as other artefacts linked to humans, including shell beads, bone tools and braided hair. 

Dr Churchill said evidence showed the devils acted like a clean-up crew, scavenging on animal remains and scraps from the camps of humans.

"I think that this is what's particularly interesting about this story is that Tasmanian devils may have had a much closer place in the lives of ancient Australians than we previously recognised," he said.

Devils driven out by dingoes

The arrival of the dingo about 4,000 years ago is a suggested cause for the extinction of the devils from the Australian mainland, with the animals estimated to have disappeared about 800 years later.

Researchers said the arrival of dingoes in the Pilbara may have disrupted the relationship between Tasmanian devils and humans.

"Did the dingo directly kill and eat the devils or were they just competing with them over food sources?" Dr Churchill said.

"Perhaps dingoes replaced the devils as a man's best friend, as the scavenger of their bones and their waste."

Apex competition

Curtin University's Bill Bateman said dingoes were Australia's apex mammal predator.

"Dingoes are great hunters and great opportunists," he said.

Associate Professor Bateman said it was likely dingoes had an effect on the mainland Tasmanian devil populations.

"There was still a period of time when both species existed together for about a thousand years before the devils' mainland extinction," he said.

"But at the same time the climate was changing, becoming more arid, so it may have been a combination of effects."

Incredibly significant site

Juukan Gorge gained international attention in 2020 when Rio Tinto detonated explosives near two rock shelters at the site. The Puutu Kunti Kurrama and Pinikura (PKKP) Aboriginal Corporation has been re-excavating and remediating the area. 

Dr Churchill said the site was incredibly rare.

"It is actually the only site in northern Australia that has animal remains in close association with stone artefacts and human occupation," he said.

"Juukan Gorge is by far the most interesting archaeological site, certainly from a zooarchaeological perspective, that we've found so far in Australia."

PKK Land Committee chair Burchell Hayes said the excavation of the devil fossils was just one part of the story emerging from the site.

 "While it is another reminder of what has been lost, finding remains of Tasmanian devils at the Juukan rock shelters again highlights their incredible significance both culturally and scientifically," he said.

"The conclusion they were scavenging off human camps more than 40,000 years ago again links ancestors of the Puutu Kunti Kurrama people to the area."