A rare discovery: we found the sugar glider is actually three species, but one is disappearing fast



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Teigan Cremona, Charles Darwin University; Alyson Stobo-Wilson, Charles Darwin University; Andrew Baker, Queensland University of Technology; Steve Cooper, South Australian Museum, and Sue Carthew, Charles Darwin University

Most Australians are familiar with the cute, nectar-loving sugar glider (Petaurus breviceps), a marsupial denizen of forests in eastern and northern Australia.

However, our new study shows the sugar glider is actually three genetically and physically distinct species: Petaurus breviceps and two new species, Krefft’s glider (Petaurus notatus) and the savanna glider (Petaurus ariel).

This discovery has meant the distribution of the sugar glider has substantially reduced, and it’s now limited only to coastal regions in southeastern Australia. The devastating bushfires last summer hit this part of Australia hard.




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Our new species from northern Australia, the savanna glider, is particularly at risk, living in a region that’s suffering ongoing small mammal declines. We must urgently assess the conservation status of both the sugar glider and savanna glider before they’re lost.

These gliding abilities likely evolved to adapt to Australia’s open forests.
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Nature’s BASE-jumpers

Our discovery of new Australian mammal species is rare and exciting. That’s because while Australia is filled with hidden and undiscovered animal and plant diversity, our mammal fauna is considered relatively well known, with more than 99% of all species scientifically described.

Perhaps Australia’s most graceful mammals, species of the genus Petaurus (meaning “rope-dancer”) have the unique ability to expand the skin between wrist and ankle to glide from tree to tree – they are nature’s BASE-jumpers. It’s believed these gliding capabilities evolved as a way to adapt to the open forests of Australia.

The palm-sized sugar glider, named after its insatiable appetite for all things sweet, is the most widely known member of the genus and is commonly kept and bred in captivity around the world.

From the Aussie outback to London’s Natural History Museum

An investigation into sugar glider genetics a decade ago highlighted two divergent groups within the species, suggesting sugar gliders may represent more than one species.

In that study, scientists also unexpectedly found that one glider from Melville Island in the Northern Territory was genetically distinct from sugar gliders. Instead, this Melville Island glider showed a close relationship with two larger existing species, the squirrel glider (Petaurus norfolcensis) and mahogany glider (Petaurus gracilis).

Prompted by this unusual finding, we investigated the mysterious glider’s identity.

We studied more that 300 specimens from museums to the Aussie outback.
Teigan, Author provided

From some of the most remote areas of outback Australia to our vast national museum collections, and ultimately the hallowed halls of London’s Natural History Museum, we captured, measured and compared every glider we could find to evaluate their relationships.

Indigenous knowledge of the savanna glider Petaurus ariel and the contributions of local Aboriginal people were also invaluable to our investigation.

The savanna glider is culturally significant and valued across multiple language groups in northern Australia and we are grateful to the Traditional Owners for sharing their knowledge of the species and its habitat.

In the end, we assessed more than 300 live and preserved specimens and established three species where once there was one.

Meet the new gliders

The savanna glider lives in the woodland savannas of northern Australia and looks a bit like a squirrel glider with a more pointed nose, but much smaller. The remaining two species look similar to each other and may overlap in some areas of southeastern Australia.

Sugar gliders are restricted to forests East of the Great Dividing Range.
Michael J Barritt, Author provided

Krefft’s glider has a clearly defined dorsal stripe and fluffy tail. It is widespread in eastern Australia and has been introduced to Tasmania.

The sugar glider, with a less-defined dorsal stripe, is apparently restricted to forests east of the Great Dividing Range, extending from southeast Queensland to around the border of New South Wales and Victoria.

What does this mean for sugar gliders?

Despite ongoing debate about the role of taxonomy (the science of classifying species) in conservation, it is clear from our work that species definitions provide an essential foundation for effective conservation.

Sugar gliders use tree hollows, which makes them vulnerable to intense bushfires.
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When considered as one species, sugar gliders were widespread, abundant and officially classified as “least concern”.

The distinction of these three species has resulted in a substantially smaller distribution for the sugar glider, making the species vulnerable to large scale habitat destruction, such as the recent bushfires.

And sadly, the bushfires have incinerated a large proportion of the sugar glider’s updated range. Given they are tree hollow users and require a diverse habitat with a variety of foods, the bushfires have most likely had a devastating effect on this much-loved species.




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The savanna glider is disappearing

Our work has shown urgent intervention is needed to save this important plant pollinator and icon of the Australian bush.

The savanna glider in particular is facing its own conservation concerns in the ongoing northern Australian small mammal declines. Tree-dwelling mammals are among those worst affected there, and it appears the savanna glider is no exception.

This is a rare discovery as most Australia’s mammals are considered already known.
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An earlier study of ours showed the species has undergone a 35% range reduction over the last 30 years, and is slowly disappearing from the inland areas it once inhabited. It’s likely feral cats, changed fire regimes and feral herbivores have played a significant role in the savanna glider’s vanishing range.

It would be a tragedy if this species is lost to the world just as it was discovered, especially with Australia’s appalling track record of human-induced mammal extinctions.




Read more:
Scientists and national park managers are failing northern Australia’s vanishing mammals


More scientific work is urgently needed. We must define the distinct ecology of each species and determine their distribution in more detail.

This will enable us to effectively assess the conservation status of each species and determine what management efforts are required to ensure their protection as they face an uncertain future.The Conversation

Teigan Cremona, Research Associate, Charles Darwin University; Alyson Stobo-Wilson, Postdoctoral Research Associate, Charles Darwin University; Andrew Baker, Senior Lecturer, Queensland University of Technology; Steve Cooper, Principal Researcher , South Australian Museum, and Sue Carthew, Provost and Vice President, Charles Darwin University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Swift parrots need protection from sugar gliders, but that’s not enough



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Without help, Tasmania’s swift parrots could be wiped out within three generations.
JJ Harrison/Wikimedia Commmons, CC BY-SA

Dejan Stojanovic, Australian National University; Matthew Webb, Australian National University, and Rob Heinsohn, Australian National University

Swift parrots are icons of Tasmania’s old-growth forests, but they’re also pretty tricky to find. These highly nomadic birds settle in a different place each year to breed, leaving nesting sites deserted for years between breeding events. This mobility makes them fascinating to study, but a nightmare to conserve.

Despite their elusive nature, we know enough about swift parrots to know they are under grave threat, particularly from Tasmania’s highly politicised logging industry.


Read more: Sugar gliders are eating swift parrots – but what’s to blame?


In the context of ongoing habitat loss to logging, swift parrots were listed as critically endangered, because of the impact of another surprising factor: predatory sugar gliders, an introduced species to Tasmania.

About half of the female swift parrots that attempt to nest in Tasmania are eaten by sugar gliders each year. This alone could be enough to wipe out swift parrots within three generations. To try and combat this, we are aiming to install mechanical doors on swift parrots’ nest boxes, which close at night to stop the nocturnal sugar gliders getting in.

A mechanical door that closes the entrance to swift parrot nest boxes at night, protecting them from predatory sugar gliders.

Happy campers by day.
ANU, Author provided
Safe and sound by night.
ANU, Author provided

Ongoing logging makes the issue even more pressing. Nests seem to be more vulnerable to sugar glider predation if nearby areas have been logged. This means that the ongoing deforestation from logging is likely to make the parrots’ plight even worse by both reducing available habitat and worsening predation risk.

Failure to protect swift parrots was a key reason why Sustainable Timber Tasmania (formerly Forestry Tasmania) failed to attain Forest Stewardship Council certification. Despite repeated attempts to resolve parrot protections over the past decade, logging continues to destroy known swift parrot nesting trees.

Recent logging in Tasmania’s Southern Forests.

Logging known swift parrot nest trees is against the recommendations of the industry regulator, the Forest Practices Authority. Yet Tasmania’s Regional Forest Agreement (RFA) exempts logging companies from federal conservation legislation.

The future of currently unlogged areas also remains uncertain. Many areas of known swift parrot habitat are scheduled for future logging, raising the prospect that yet more habitat will be cut down in the next few years.

Large areas of swift parrot habitat can still be legally logged under the Tasmanian Regional Forest Agreement, despite impacts on the critically endangered population.

While illegal logging of individual trees has been the subject of investigation under federal law, large areas of known swift parrot habitat are still being cut down, entirely legally, under the RFA.

This swift parrot nest hollow was felled by illegal wood cutters, resulting in an investigation.

Based on the existing evidence, we suggest that all logging of known swift parrot habitat should stop immediately. But given the recent renewal of the RFA and the intense politicisation of the forest industry in Tasmania, this kind of evidence-led rethink is unlikely to be forthcoming.

Protecting swift parrots is hard, because a truly effective strategy will require both large-scale habitat protection across Tasmania, and small-scale action such as our interventions against sugar glider predation.


Read more: Let’s stop Tasmania’s swift parrots going the way of the dodo


We are crowdfunding a project to install mechanical doors on 100 nest boxes deployed in sugar glider infested forest on mainland Tasmania.

Mobile species like swift parrots can’t be saved simply by creating a nature reserve and then walking away. Swift parrots are difficult to study and even more difficult to protect.

The ConversationWe need fresh thinking about how to manage these birds in landscapes used by the logging industry. Business as usual could easily end in extinction.

Dejan Stojanovic, Postdoctoral Fellow, Australian National University; Matthew Webb, , Australian National University, and Rob Heinsohn, Professor of Evolutionary and Conservation Biology, Australian National University

This article was originally published on The Conversation. Read the original article.