Quolls and bettongs delivered to the far north-west corner of New South Wales are the final piece of a decade-long project to reintroduce seven locally extinct mammals to the arid desert landscape.
Twenty burrowing bettongs and 20 western quolls have been released into Sturt national park as part of the Wild Deserts project. They joined previously released and flourishing populations of bilbies, bandicoots and mulgaras (a small but ferocious native predator).
Dr Rebecca West, Wild Deserts principal ecologist, said six out of seven mammals had been successfully returned to the park and were helping to repair damage wrought since European colonisation.
“It’s like time-travelling”, she said. “We’re reversing and going back to what it would have been like 200 years ago if you set up camp in the Strzelecki desert.”
In daylight hours, the work of “ecosystem engineers” – the bilbies and bettongs – was evident in vegetation like saltbushes and sticky hop bushes which sprouted from seeds that collected in foraging pits, she said. “They dig for their food and burrows, and that turns over the soil and helps with plant growth and nutrient cycling.”
Night-time was when the “real magic happens”, she said. “You can drive along and see a bilby dart across the track in front of you, or a Shark Bay bandicoot with a couple of young trailing after it.”
The arid zone, which covered 70% of Australia, was one of the country’s most changed ecosystems, West said. As native mammals were “wiped out”, the desert environment became less resilient and less diverse.
A partnership between Wild Deserts and NSW National Parks was reversing that process. Starting with bilbies and mulgaras, mammals had been gradually reintroduced into two predator-free havens and a larger 100 sq km “training zone”.
Wild Deserts project leader, Prof Richard Kingsford of UNSW, said mammal numbers had multiplied within the havens from about 100 to 1,000 individuals. There had been noticeable recovery elsewhere in the park, including invertebrates, plants, lizards and small mammals. “It’s surprising to see how quickly some populations bounce back,” he said.
Kingsford said the larger training zone played a crucial role in the project. It was enough room for quolls to move around in and a leaky fence that let in small numbers of feral cats provided an opportunity to test cat control measures. It also gave native mammals released into the zone an opportunity to adjust their behaviour in the presence of predators, preparing them for life beyond the fence.
Quolls and bettongs were supplied by Arid Recovery in South Australia and Taronga Western Plains zoo in NSW. Some burrowing bettongs arrived by plane from South Australia.
Arid Recovery’s CEO, Dr Katherine Tuft, said the bettongs were endearing and robust little macropods which were “about the size of a football, and roughly that shape”.
Bettongs readily survived in tough, desert environments, she said, eating “just about anything” and breeding well. When Arid Recovery ended up with “too much of a good thing”, they brought in quolls as a native predator, an experience that is now being applied in the Wild Deserts project.
A parcel of quolls came from Taronga Western Plains zoo in Dubbo, an eight-hour drive away. Taronga’s CEO, Cameron Kerr, said the organisation’s in-house veterinary, behavioural and conservation scientists supported its role as a specialist “production house for rewilding”.
The cat-sized carnivores travelled calmly, he said. Once released they moved rapidly, finding cozy drains or abandoned burrows to hunker down in.
Stick-nest rats were the only species reintroduced to the park that did not survive. West said more work was needed to create the conditions needed for them to thrive.
Prof Euan Ritchie, a wildlife ecologist at Deakin University who was not involved with the project, said reintroducing mammals was challenging but had many benefits, including for First Nations people as many species were culturally significant.
The project was good news in a country like Australia, which had one of the worst conservation records, he said. Every project offered “valuable lessons” that could be applied elsewhere.
“We’re going to make mistakes along the way, but we’re also going to learn a lot and hopefully have increasing success in the future.”
