The potoroo is described as an elusive forest dwelling marsupial. Credit:Leo/Flickr. The fence was built earlier this year to protect a local road being used to carry gravel and rocks to the nearby highway-upgrade site. Wildlife ecologist David Milledge set up cameras in the aftermath of the fire, which snapped photos of potoroos on the bushland floor, where he fears they will be exposed to predators. "The population is being squeezed between the fire and highway corridor," he said. "They are very susceptible to predation from introduced species unless they have cover."

Surveillance photographs of the long-nosed potoroo show them on the bushland floor, where they may be exposed to predators. Koalas are also under pressure as a result of "canopy incineration" and tree collapse caused by the wildfire, Mr Milledge said. The RMS said animals can move through the fence, which is designed to stop them wandering on to the road. The fence includes a 30-metre gap that allows the potoroos to pass through, as well as four escape structures built at either end. "Regular monitoring and surveillance of all activities continues on ground, complemented by regular performance reporting," a spokeswoman for RMS said. The government's plans have been controversial. Sue Arnold from Australians for Animals believes safety precautions to protect native fauna are inadequate and said koalas would suffer as work on the road continued.

"What the RMS has done is a huge experiment without an ethics committee, which denied the animals access of movement," she said. The department said its plans had been reviewed by independent experts before being approved by the NSW Department of Planning and Environment. The koala-proof fence lines Old Bagotville Road, which will be used by trucks to ferry rock and gravel from two quarries to the road construction site. The road will carry an average of 250 trucks and 100 cars each day for about four months. In July, the Environmental Defenders Office, on behalf of Australians for Animals, wrote to federal Environment Minister Josh Frydenberg, accusing RMS of breaching its approval conditions by failing to explore safe pathways for animals to cross the road. In response to the letter, the Department of Environment and Energy said it undertook a site inspection and was satisfied that "actions have been undertaken consistent with the approval conditions and supplementary management plans".

In October, the Environmental Defenders Office wrote a further letter to the department claiming that bushfire risks had not been considered. The department said it was considering the information provided. About 200 koalas are believed to live within two kilometres of the highway upgrade. According to a government review of koala numbers in the area, it is a population in decline, under pressure from disease and predation, which has put the long-term survival of the colony at risk. "There are domestic dogs, wild dogs, road strikes, loss of habitat - it is unsustainable. The population can't take the stresses and it is well known koalas are susceptible to stress," Mr Milledge said. Local environmental groups fear the sound of blasting from the local quarries, now in use to supply gravel for the highway upgrade, will spook the koalas during the crucial breeding season. Koalas produce a distinctive bellowing call during the breeding season. It's feared low frequency noise by excavation machinery at the quarries may interfere with the calls and interrupt the koala's normal breeding habits.

"There have been a number of studies with local koala populations close to music festivals and it has found that these one-off noises can be very damaging to koala populations," Mr Milledge said. RMS did not respond to questions about the potential danger of noise posed by the quarry work.