Leadbeater’s possum spotted outside Victoria for first time
The possum was photographed near Yarrangobilly Caves in the park’s north by trail cameras installed by the Department of Climate Change, Energy, the Environment and Water (DCCEEW) to survey smoky mouse populations.
Until now, the critically endangered marsupial was thought to be endemic to Victoria and extinct in New South Wales, known only from fossils from Yarrangobilly and Wombeyan caves.
A new subspecies
The Leadbeater’s possum (Gymnobelideus leadbeateri), which weighs just 100–160g, is impossibly cute with dark, protuberant eyes and a small, fluffy body. It’s little wonder it’s Victoria’s faunal emblem.
The nocturnal marsupial occurs in montane ash forests and subalpine woodlands. Victoria is home to two genetically distinct populations: highland populations across the Central Highlands, and a tiny lowland population found only in the Yellingbo Nature Conservation Reserve east of Melbourne.
It’s likely the possum photographed inside Kosciuszko NP is its own unique subspecies. Now, conservationists are eager to get genetic samples to confirm this.
“Once the genetic results are in, I expect that we will have northern Leadbeater’s possums in NSW and southern Leadbeater’s possums in Victoria, each with distinctive management requirements,” said Dr Dan Harley, a senior ecologist at Victoria’s Healesville Sanctuary.
The discovery raises a number of questions, including the population size and distribution of Leadbeater’s possums in NSW.
“The extent of the species’ occurrence in NSW has yet to be determined, and the discovery does not alter the major challenges we are facing to conserve this possum in Victoria,” Dr Harley said. “While the NSW discovery is exciting and quite unexpected, it in no way alters the species’ critically endangered status at this stage.”
A wild hunch
Professor David Lindenmayer, an ecologist from the Australian National University’s (ANU) Fenner School of Environment and Society, has long suspected that Leadbeater’s possums might live inside Kosciuszko NP because of its suitable habitat.
Thirty-five years ago, he surveyed for Leadbeater’s possums at Yarrangobilly as part of his PhD, but he couldn’t find any.
“Bioclimatic modelling indicated that the area should suit the Leadbeater’s possum, so I looked for them there and in many other parts of Kosciuszko National Park. But this was before camera traps were widely available, and I was unsuccessful in detecting them,” he said.
“This discovery shows that just because a species hasn’t been positively detected at a location, you cannot be confident that it isn’t there. Many of our most imperilled species are hard to detect.”
It’s likely more discoveries will be made as camera traps and thermal equipment become more sophisticated and are deployed more regularly.
“Kosciuszko National Park is 690,000ha, most of which is forest that has never been properly surveyed,” Professor Lindenmayer said. “How exciting it is to live in a country where new discoveries are being made!”
