greater glider
© Josh Bowell
The furry flyers vary in size, getting smaller the further north they live.
There are two more reasons to love Australia's fluffiest aeronautical marsupials after the discovery that there are actually three species of greater glider, not one as previously assumed.

The greater glider is a possum-sized marsupial living in the forests of eastern Australia, squeezing into tree hollows during the day and at night soaring up to 100 metres through the air on the hunt for its favourite eucalyptus leaves.

A study of the genetics of greater gliders, published in Nature's public access Scientific Reports journal, found distinct species in the southern, central and northern ranges.

"Australia's biodiversity just got a lot richer. It's not every day that new mammals are confirmed, let alone two new mammals," one of the study authors, James Cook University Professor Andrew Krockenberger, said.

The furry flyers vary in size, getting smaller the further north they live.

The southern species, which inhabits the eastern eucalypt forests of Victoria and NSW, is the heavyweight of the family. Its puffy fleece makes it look about the size of a common brush-tailed possum, but underneath it's really a skinny, light marsupial suited to gliding.

Very little is known about the two other species, said another study author, Australian National University ecologist Kara Youngentob.

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.

The variation in size between glider populations was noted when it was first described to science, but it was assumed the gliders were one species with different traits depending on their habitat.

James Cook University PhD candidate Denise McGregor said there had been speculation for some time that there was more than one species of greater glider. "Now we have proof from the DNA, it changes the whole way we think about them".

A biodiversity survey conducted by Star of the South wind farm off the coast around Gippsland shows a huge range of fish and sea creatures.

Gliders were considered common across their range as recently as 30 years ago but are now listed as vulnerable on the national list of at-risk wildlife. Habitat loss from logging and urban development, coupled with climate change, have pushed them out of many former strongholds.

Southern glider populations have declined 80 per cent in the past 20 years in Victoria's Central Highlands. They've also become extinct at Jervis Bay on the NSW South Coast and in the lower elevations of the Blue Mountains.

Dr Youngentob said conservation of gliders became more urgent and challenging now there were three species to protect.

"It's really exciting to find this biodiversity under our noses, and gliders are such a charismatic animal as well," she said.

glider

The northern species of greater glider (top left), central species (bottom left) and the southern species.
"But the division of the greater glider into multiple species reduces the previous widespread distribution of the original species, further increasing conservation concern for that animal and highlighting the lack of information about the other greater glider species."

Dr Youngentob said climate change had already reduced populations because it increased the prevalence of "extreme" night time temperatures in the southern glider's range.

"For the southern species, anything over 20 degrees Celsius at night means it has to use its energy to actively cool itself and high temperatures also put them off their food and stop them eating."