Research carried out by Australian Wildlife Conservancy (AWC), Queensland Parks and Wildlife Service (QPWS) and Western Yalanji Aboriginal Corporation (WYAC) has revealed that the total population of one of the two remaining populations of endangered Northern Bettong is much smaller than first anticipated and may be declining. The results, which will be presented today at the Annual Conference of the Ecological Society of Australia, implicate changed fire patterns, feral animals (cattle and pigs) and weeds as persistent threats to the dwindling marsupial population.
Listed as endangered under federal and state legislation, the Northern Bettong has previously been identified as one of the mammal species at highest risk of extinction if threats are not urgently addressed. There are currently two populations, the larger and more intensively studied is on the Lamb Range, where there are between 700-1000 individuals. Research over the last 20 years has revealed this population is stable. The second population, found on the Mount Carbine Tableland, was almost unknown. Recognising the imminent danger to the species, AWC has been working with QPWS and WYAC since 2017 to understand how many bettongs remain on the Mount Carbine Tableland and what the key threats are where they survive.
Using an array of 128 motion-sensor camera traps, the team has been able to detect the animals and map out the extent of the Mount Carbine Tableland population. Data was also obtained through live trapping, using 50 cage traps deployed across the same area, and all individuals caught were microchipped for future identification. Analysis of the data shows that the bettongs occupy just 23 km2. Concerningly, the latest estimate of population density within this small area determined earlier this year is lower than previously found and was just 1.45 animals/km2. The resulting estimate of less than 50 animals remaining brings into question the viability of this critical population, even in the short term.
“WYAC, QPWS and AWC are working closely to halt the decline of Northern Bettongs on Western Yalanji country before we lose the remaining population forever,” said Richard Grogan, Western Yalanji Aboriginal Corporation Chairperson. “Last year, QPWS secured funding and constructed a cattle blockage fence which was culturally cleared by Western Yalanji. The purpose of the fence is to stop competition and disturbance from cattle within the national park and we are working with QPWS to implement a fire management program.”
“The next step is to muster the cattle out of the area and continue the ongoing fire and weed management strategies to improve the suitability of the Northern Bettong habitat. We will also continue to closely monitor the population over the coming years.”
“Research at Mt Lewis has identified the population of Northern Bettongs on the Mount Carbine Tableland is much smaller than we thought and at risk of going extinct,” said Dr Manuela Fischer, Australian Wildlife Conservancy Wildlife Ecologist. “As specialist fungivores which eat and disperse truffles, Northern Bettongs play an essential role in maintaining the forest’s health – losing them would not only be a tragedy in itself, it would also have ripple effects across the wider ecosystem.”
“Urgent action is underway to stop the decline, but it’s a race against the clock. AWC is in the process of establishing a feral predator-proof fence at Mt Zero-Taravale Wildlife Sanctuary outside of Townsville, where we hope to reintroduce the species and provide them with a safe haven to rebuild their numbers.”
The Northern Bettong belongs to a family of small statured kangaroo-relatives (the bettongs and potoroos), which have suffered severe declines and extinction since European colonisation. Standing just 30cm tall, the Northern Bettong has extravagant tastes – its diet consists largely of truffles which are the fruiting bodies of underground fungal networks. The potoroos’ preferred habitat is the open eucalypt forests that fringe the rainforests of the Wet Tropics. They require an open structured forest with a grassy understorey, which supports the proliferation of the fungus on which they feed.
To safeguard the future of this species, generous grants from the NSW Wildlife Information Rescue and Education Service (WIRES) for $568,700 and $1.5 million from the federal government’s Environment Restoration Fund’s Safe Haven Grant are supporting construction of a feral predator-free area at Mt Zero-Taravale Wildlife Sanctuary and the return of the endangered Northern Bettong. The 13-kilometre fence will create a 950-hectare feral predator-free refuge that will be the first of its kind in northern Australia. The work at Mount Carbine Tableland was also supported with funding from the Queensland Government’s Community Sustainability Action Grant program.