A small population of brush-tailed bettongs have been reintroduced to Yorke Peninsula, South Australia, where they have been locally extinct for more than 100 years.
Key points:
- 40 brush-tailed bettongs have been released onto the South Australian mainland
- The animals are fitted with radio-tracking collars to allow for tracking
- Between 10,000 and 20,000 bettongs are believed to be in the wild in Australia
Some 28 females and 12 males were released into Dhilba Guuranda-Innes National Park last week after being translocated from an abundant population of more than 1,500 on Wedge Island.
Located about 33 kilometres off the west coast of the park, the island’s population is abundant with the small marsupials, also known as woylies.
Zoos SA conservation manager Liberty Olds said bettongs were introduced to Wedge Island in the 1970s.
“The island itself doesn’t really have any predators for bettongs, so they’ve had quite a successful life on Wedge Island, and provided us with a really great place to be able to source some animals,” Dr Olds told ABC Radio Adelaide.
She said some of the translocated females had young in their pouches.
Fenced off from predators
The rewilding of bettongs on Yorke Peninsula is part of the Marna Banggara project, a 150,000-hectare safe haven comprising of the national park, conservation parks, remnant vegetation, farmland and small townships.
Cordoned off by a 25-kilometre fence across the foot of the peninsula, the Marna Banggara project is considered unique because the area is part of a working landscape involving community, agriculture and local businesses.
“It (the fence) does not 100 per cent shut it off because, as you imagine, it’s a big area and there’s a lot of people that still live in the area,” Dr Olds said.
“But there’s wings at the roadsides and targeted areas where we are able to reduce the numbers of predators and control that incursion from happening.
Groups involved include the Narungga Nation Aboriginal Corporation, the state government, Zoos SA, the Northern and Yorke Landscape Board, World Wildlife Fund Australia and Foundation for National Parks & Wildlife, Conservation Volunteers Australia, Yorke Peninsula Council, the National Landcare Program and the National Parks and Wildlife Service SA.
Population decimated
Brush-tailed bettongs once occupied more than 60 per cent of mainland Australia but the introduction of feral predators like foxes and cats decimated their numbers.
It is believed their population has plummeted from about 225,000 nationwide, to between 10,000 and 20,000 in the wild, with populations remaining only in Western Australia and on SA islands.
The Wedge Island bettongs are the first of several planned reintroductions, chosen because they spread native seeds and dig up between two to six tonnes of dirt and ground matter a year, which aids water infiltration of the soil and cycles valuable nutrients.
Federal Environment Minister Sussan Ley said the pilot release was the first step in rewilding a number of native species across the southern Yorke Peninsula.
“More than a century ago, they (bettongs) were wiped out locally by feral predators and their return is a major step in rewilding research and of enormous significance to the local Narungga community,” Ms Ley said.
On their way
Most were fitted with radio tracking collars so their progress could be monitored via radio towers through the University of Adelaide.
“We know that they are surviving and we also know if there’s any deaths in the populations, so we can go and look at those animals and find out what’s happened if that occurs,” Dr Olds said.
At the moment, however, the 40-plus animals are doing well.
“A lot of work goes in beforehand to look at that habitat and choose the sites where we know there’s going to be reliable food sources and shelter for them,” Dr Olds said.
Another 80 Western Australian bettongs and 80 SA bettongs will be released at Marna Banggara over the next two years, with other locally extinct species planned for reintroduction including the southern brown bandicoot, red-tailed phascogale and western quolls.
Brush-tailed bettongs were also released into the Northern Territory this month under a different program.