By Mike Foley
The extinction risk for greater gliders in NSW and Victoria has been upgraded by the federal government, which now rates the species once common in eastern forests as a risk of dropping off the planet in coming years.
Habitat loss from logging, land clearing for agriculture, intensifying bushfires and rising average temperatures have combined to turn the largest gliding possum in eastern Australia’s forests into a rarity.
After escalating the species’ listing from vulnerable to endangered, federal Environment Minister Tanya Plibersek said greater priority would be placed on conservation efforts for “iconic” greater gliders, which range from Proserpine in North Queensland’s Whitsunday region to central Victoria.
“The government is determined to take real action to protect our native species and their habitats,” Plibersek said.
Greater gliders are susceptible to bushfires as they rely on mature trees with hollows to survive. This is particularly devastating as natural hollows, their homes, can take up to 100 years to form.
Gliders squeeze into tree hollows during the day and soar up to 100 metres across the forest air at night, hunting for their favourite eucalyptus leaves, shoots and flowers.
But selective logging has changed the composition of forests, particularly around Eden on the NSW South Coast and in north-east Victoria, and they are now “dominated by tree species that gliders can’t eat,” Australian National University ecologist David Lindenmayer said.
He said Australia had “absolutely buggered up the management of this animal”.
“It used to be one of the most common species that you would see if you went surveying or spotlighting 30 years ago,” Lindenmayer said.
“This fantastic, iconic animal and, for all intents and purposes, like a small gliding koala – which is really Australia’s equivalent of the panda.
“It’s sensitive to its habitat being logged. It’s sensitive to clearing, it’s very sensitive to climate change. It’s sensitive to fire.”
Scientists were astonished two years ago when a breakthrough study found there are actually three species of greater glider, not one as previously assumed.
The southern greater glider, which lives in NSW and Victoria’s eastern forests, is the largest of the family with a head and body length of 35 to 46 centimetres, a tail length of 45 to 60 centimetres and weighing up to 1.7 kilograms.
The northern glider is about the size of the little ringtail possum and lives in the eucalypt forests between Mackay and Cairns in Queensland. The central glider, which is sized between the northern and southern species, inhabits a range across southern Queensland and up to Mackay.
Very little is known about the two northern species.
Gliders were previously listed as vulnerable – which is designated when a species faces a high risk of extinction in the medium term.
The southern greater glider is now listed as endangered, which means the species is at high risk of extinction in the short term.
Lindenmayer welcomed the endangered status but said dramatic habitat protections and action to reduce global warming were needed to prevent the extinction of greater gliders.
“This is a species we’re going to lose if we don’t get our shit together. Yeah, it’s fantastic that it’s been listed [as endangered]. I think that’s great. But they’re just words. We actually have to take sensible actions.
“The world is looking at Australia and going ‘oh, my god, this place leads the world in mammal extinctions’. Last decade, we lost another three species and we’re still dithering around.”
The federal government cited a population estimate of more than 100,000 greater gliders in NSW and Victoria, which was conducted in 2014. It said greater gliders had suffered a rate of population decline exceeding 50 per cent over the past 21 years, or three generations, including the destruction of more than 35 per cent of habitat in the 2019–20 Black Summer bushfires.
The Australian government is investing $1.69 million into projects that are targeted at benefitting the species through on-ground actions like the installation of artificial tree hollows and targeted revegetation.
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