A rare native marsupial crucial to the survival of Queensland's tropical ecosystem is facing a deadly decline, a new study has revealed.

Key points: Northern bettongs survive on a diet of truffles for the majority of the year

Northern bettongs survive on a diet of truffles for the majority of the year Approximately 2,500 northern bettongs are left in the wild

Approximately 2,500 northern bettongs are left in the wild Feral cats, poor land management and fire pose the biggest threats

The five-year WWF-Australia-funded project — which tracked the northern bettong — found there had been a 70 per cent decline in the marsupial's population in the past 30 years.

Project leader Caitlin Weatherstone said scientists were relieved to find the bettongs in two regions.

"We were able to find them in two areas, one in the Lamb Range north of Cairns and one in the Mount Carbine Tableland, west of the Daintree," Ms Weatherstone said.

"But that's where the good news ends. We didn't find them anywhere else in their previous range.

"We zoned in on 11 key areas and we were only able to find them in two."

The northern bettong has expensive tastes, surviving for most of the year solely on truffles.

Ms Whitehouse said their diet was key to the survival of the region's forests.

She explained: "The northern bettongs dig up truffles, they smell beautiful to them, and they eat them.

"That process helps the truffle disperse its spores.

The Northern Bettong survives on a diet of truffles for the majority of the year. ( Supplied: SJ Nuske )

"And in turn, they grow on the roots of the eucalypts in the area, which helps them grow.

"If you lose one step of that process, biodiversity suffers."

Predators such as feral cats, poor land management, and fire are known threats to the approximately 2,500 northern bettongs left in the wild.

The northern bettong project has prompted calls to establish an "insurance population" by fencing off an area to predators or moving some of the animals to an island, to make sure the marsupials do not disappear completely.

Tim Cronin from WWF-Australia pointed out the bushfires that ravaged Queensland had the power to decimate the tiny northern bettong population.

"That gave us a really stark reminder that, particularly with climate change, those kinds of fires are increasing in intensity and frequency.

"All it's going to take is one of those to wipe out this population, so we need to stop that happening," Mr Cronin added.

The plight of the northern bettong has prompted fresh calls to speed up protection measures for other endangered animals.

A recent report by the Queensland Audit Office found it was taking up to seven years between assessing and studying animals at risk and state authorities acting to protect them.

And a Senate inquiry is currently investigating Australia's threatened species crisis including environment laws and funding arrangements.

Mr Cronin said any delays in protecting the northern bettong could be deadly: "We want everything to be based on the most rigorous and up-to-date science.

"But that can also translate to sitting on our hands.

"When it comes to threatened species and ecology we'll never have all the information, but often we'll have enough information to act.

"We need to get on the front foot, not sit around and wait."

Queensland's Environment Department said it had been directly involved in protecting the northern bettong for several years.

It added the State Government would continue to work closely with WWF-Australia and other organisations to protect the remaining population.