Researchers have rediscovered one of Australia’s rarest marsupials – the northern bettong – near Mount Carbine in Queensland’s far north.
In a breakthrough, a sensor camera photographed two bettongs side by side in Mount Lewis National Park with a third individual photographed nearby. All three were detected within a two-square-kilometre section of the park.
Northern bettongs have dramatically declined in the past 20 to 30 years and are listed as endangered.
For more than a decade the only confirmed location for the species was Lamb Range near Cairns. It was feared the northern bettongs there were the last of the species to survive in the wild.
But the camera trap photographs reveal a second population is hanging on at the northern end of their historic range. More research is needed to determine the size of this population, thought to be small.
“After searching for a year and a half, and walking for hundreds of kilometres in rugged bush, this was our eureka moment,” said WWF-Australia’s Jess Koleck, coordinator of the Northern Bettong Project.
“It means we don’t have all our eggs in one basket. If a major fire or disease outbreak greatly reduced the Lamb Range population, there are at least some survivors to the north. The situation just got slightly less dire,” she said.
The Northern Bettong Project is a collaboration between WWF, James Cook University and the Queensland Government. Indigenous groups and local community members are also partners in the project. Funding has been provided by a grant from the Australian Government’s Caring for Our Country initiative.
Pooling their resources, the three organisations were able to put more than 100 sensor cameras in the field in the search for northern bettongs.
Rangers from the Queensland Parks and Wildlife Service, a JCU student and WWF’s Jess Koleck undertook the field work that resulted in the discovery.
The cameras were set about a kilometre apart in rows about five kilometres long and left in place for more than a month before being moved. Bait balls of peanut butter, oats, vanilla and truffle oil – known to be irresistible to northern bettongs – were were placed near the cameras.
The baits were locked in containers with perforated lids and pegged to the ground so that the first animal to walk by couldn’t eat the lure or carry it away.
Northern and spotted-tailed quolls, bandicoots and possums are among the animals which have set off the cameras, generating more than 100,000 photographs.
“Looking through a mountain of images has been a slow and tedious process. But we were all celebrating when there on the screen were northern bettongs from three different camera points. With only about half the photos sorted from this site, we’re hopeful of finding more. But it seems likely their range up in the north is pretty small,” said Ms Koleck.
Bettongs’ traditional habitat is open eucalypt woodland – with a grassy understory – just west of the rainforests of north Queensland.
Scientists believe these tiny marsupials play a crucial role in the health of the woodland. They mainly feed on truffles which grow underground on the roots of large trees.
The truffles fix nutrients in the poor soil that the trees need and use, while the trees provide sugar from photosynthesis to the truffles.
When bettongs consume truffles they spread the spores about the forest in their droppings. While other animals also eat truffles, bettongs eat a high proportion and variety including some truffle species it’s believed are not consumed by other mammals. These unique eucalypt woodlands could disappear – or be substantially altered – without the bettongs.
Northern bettongs face many threats. Much of their forest home has been cleared. Cats prey on them. Foxes, largely blamed for the mainland extinction of southern bettongs, may reach their territory.
Feral pigs compete for truffles and alter their habitat. Overgrazing by cattle can trash the grassy understory where they nest.
The loss of traditional fire regimes has allowed rainforest plants to take over in places changing open woodland into denser habitat not suited to bettongs. Climate change also looms as a long term threat.
Mark Symons, WWF-Australia Senior Media Officer, 0400 985 571, firstname.lastname@example.org