The sinister growl of the Tasmanian devil went silent on mainland Australia about 3,000 years ago.

In more recent times, the screech has also faded on the island state where the creature is iconic, with 83 per cent of the devil population succumbing to disease.

Key points: An expert says Tasmanian devils can be used as a conservation tool and that there's a case to reintroduce them on the mainland

An expert says Tasmanian devils can be used as a conservation tool and that there's a case to reintroduce them on the mainland A study found a significant decline in feral cats where devils are present, while bandicoots are only abundant at sites where cats are rare

A study found a significant decline in feral cats where devils are present, while bandicoots are only abundant at sites where cats are rare The devil was found across mainland Australia until it disappeared from fossil records 3,200 years ago

University of Tasmania researcher Calum Cunningham has been studying the broader effects on the ecosystem as the marsupial's numbers declined.

"We found in areas where devils have declined severely, that feral cats were 58 per cent more abundant than areas where devils were healthy," he said.

The devils' natural pest management was also found to benefit small prey like bandicoots.

Mr Cunningham said he believed devils could be used as a conservation tool and a case could be made to reintroduce them to the mainland.

"We could see if it could have ecological benefits there too.

"Devils could reduce the number of feral cats, in turn returning benefits for the animals that cats eat."

A study has shown devils keep feral cat numbers at bay. ( Supplied: Calum Cunningham )

A bandicoot's friend

The study, published in Ecology Letters, monitored areas in Tasmania that had seen devil populations decline to varying degrees.

"We were careful to match habitat types — we surveyed rainforests, dry areas and coastal habitat," Mr Cunningham said.

Camera traps were installed to monitor cats, using markings to identify individual cats.

"We were able to run statistical models that estimated the abundance of feral cats at a given site."

The models showed a significant decline in feral cats where devils were present.

"We found that bandicoots were only abundant at sites where cats were rare," Mr Cunningham said, adding that devils mostly ate larger animals like wallabies and pademelons that were already dead or older and sick.

More than 80 per cent of the devil population has been wiped out by a facial tumour disease. ( Supplied: Rodrigo Hamede )

Devils vs foxes

The devil was found across mainland Australia until it disappeared from fossil records 3,200 years ago.

The extinction is said to be linked to the introduction of dingoes, changes to climate and human population growth and advances.

Mr Cunningham said any reintroduction of devils to the mainland must start with a controlled experiment.

"No ecologist would be suggesting an open-slather introduction of devils to the mainland," he said.

"It should be very carefully controlled in a fenced, bounded landscape."

Tasmania's fox-free status means it is unknown how devils would interact with the mainland pest.

"We expect they would compete, and I think devils would have some negative impacts on foxes," Mr Cunningham said.

"We can hypotheses about it all we like, but without an experiment, we wouldn't know."

Calum Cunningham has been studying the devil and its role as an apex predator. ( Supplied )

While Tasmania has had evidence of foxes present, there has never been a population.

"People have hypothesised that perhaps the presence of the devil was one of the reasons why foxes never established," Mr Cunningham said.

The research shows devils also reduced the abundance of possums and wallabies.

"Farmers in particular have problems with this, so that's another service the devils could be providing to the ecosystem."

"But the community has to want it as well."

The study on apex predators also looked at the impact that a lack of devils had on possums and wombats on Maria Island.

Without an apex predator, the possums spent more time foraging for food on the ground.

When devils were released into the wild, the possums returned to the trees, and wombats increased day-time activity to avoid interacting with the devils at night.