Up a gum tree: Are koalas 'slipping to extinction'?

Climate change, habitat loss, STDs and human complacency threaten the survival of Australia's cuddliest creatures

A A A

Every gum tree contains a koala, or so most Australians assume. But complacency could be killing off the emblematic native animal, according to scientists, who want it listed as an endangered species.

Already under pressure from habitat loss and disease, koalas now face a new threat: climate change. They cope poorly with the droughts and heatwaves that are expected to become more common in southern Australia in years to come. To make matters worse, increased carbon dioxide in the atmosphere is reducing the nutrient content of eucalyptus leaves, their sole food source.

Scientists say koala numbers have already declined sharply in some areas, and they warn that unless more energetic conservation measures are taken, the mammal's viability could be in doubt. "This species is supposed to be common, yet it's slipping to extinction under our noses," Christine Hosking, a nature conservationist at the University of Queensland, said yesterday.

Ms Hosking, who is researching a PhD on the impact of climate change on the koala, was one of several experts who recently gave evidence to a parliamentary committee set up to investigate the animal's health and status. She said that listing it as endangered would be a first step towards developing a national action plan to safeguard its future.

Koalas are difficult to spot in the wild, where they perch high up in gum trees, their speckled fur camouflaged against the branches. Nevertheless, with their very wide range, which encompasses much of eastern Australia, they have always been thought to be extremely numerous.

While that was once true, it may not still be the case. Population estimates are difficult to come by, because the animals are hard to count, but Clive McAlpine, a landscape ecologist at the University of Queensland, believes that there are no more than 50,000 to 100,000 left in the wild. In some areas, such as Queensland's Gold Coast, he says, populations have decreased by as much as 80 per cent over the last 10 to 15 years. Another koala expert, Bill Ellis, says that in places where researchers used to find 30 to 50 koalas in one day, only three or four are now being sighted.

Large-scale land clearing, for urban development, industry and agriculture, has progressively deprived the koala of much of its traditional habitat.

In recent years, the species has also been crippled by chlamydia, which leads to infertility and sometimes death, and a retrovirus similar to HIV, which causes various infections as well as, possibly, cancer and leukaemia.

According to Dr McAlpine, some scientists believe that the retrovirus, currently sweeping through koala populations, has the potential to be as destructive as the facial tumour disease that has almost wiped out the Tasmanian devil.

Koalas are not only being squeezed out by encroaching development, but are in danger of being run over or attacked by dogs. Now climate change is set to add to those pressures. Koalas are ill-equipped to deal with high temperatures; during heatwaves, they suffer dehydration and heat stress. Hot, dry conditions also drain the moisture out of eucalyptus leaves, from which they get most of their water. On particularly scorching days, koalas literally fall out of trees.

Ms Hosking's research shows that temperatures above 37 degrees celsius are intolerable for them. "Once you get over 37 degrees, there's zero probability of a koala," she said. "As we get more of these extreme temperatures and protracted droughts, the koalas simply won't be able to cope."

That was demonstrated during the bushfires that killed 173 people in Victoria two years ago. The fires were preceded by five consecutive days of temperatures above 40 degrees celsius, and koalas were seen climbing into swimming pools in a desperate quest for water. One fire fighter was photographed feeding a koala water from a plastic bottle.

Dr McAlpine predicted that climate change would reduce their habitat even further, pushing koalas towards the heavily urbanised east coast. "But there's not much room for them there, and there's the threat from dogs and cars," he said.

The decision on whether to list the species as endangered lies with the federal Sustainability Minister, Tony Burke, who is waiting for a report from the parliamentary committee. However, an expert panel has already recommended against the move – the second time it has rejected the call from scientists. At present, the koala is not even classed as vulnerable.

An endangered listing would facilitate conservation work, making it easier to protect remaining habitat and to find funding for research into a chlamydia vaccine. Without better protection, koala experts fear for the species. "They'll just become more and more rare in the wild, found at increasingly low densities, and populations will become unviable," said Dr McAlpine. "That's what we are concerned about."

One problem faced by scientists is that koalas are still quite numerous in certain areas, which makes it difficult to inject a sense of urgency into the debate. In many of those areas, though, they say, populations are genetically limited and riddled with disease.

Dr McAlpine said: "There's a lot of evidence to support the case for action. We can't afford to wait until the population is down to 10,000 before we do something, because by then it will be too late."

News
The clocks go forward an hour at 1am on Sunday 30 March
news
Arts and Entertainment
The Doctor finds himself in a forest version of London in Doctor Who episode 'In the Forest of the Night'
TVReview: Is the Doctor ever going stop frowning? Apparently not.
Sport
footballMatch report: Real fight back to ruin Argentinian's debut
News
Bruce, left, with Cream bandmates Ginger Rogers, centre, and Eric Clapton in 1967
people
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Money
Welcome to tinsel town: retailers such as Selfridges will be Santa's little helpers this Christmas, working hard to persuade shoppers to stock up on gifts
news
News
i100
News
people
Arts and Entertainment
Architect Frank Gehry is regarded by many as the most important architect of the modern era
arts + entsGehry has declared that 98 per cent of modern architecture is "s**t"
Arts and Entertainment
Soul singer Sam Smith cleared up at the Mobo awards this week
arts + entsSam Smith’s Mobo triumph is just the latest example of a trend
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Maths Teacher

£110 - £200 per day: Randstad Education Leeds: Secondary Maths Teacher for spe...

Business Analyst - Surrey - Permanent - Up to £50k DOE

£40000 - £50000 Per Annum Excellent benefits: Clearwater People Solutions Ltd:...

***ASP.NET Developer - Cheshire - £35k - Permanent***

£30000 - £35000 Per Annum Excellent benefits: Clearwater People Solutions Ltd:...

***Solutions Architect*** - Brighton - £40k - Permanent

£35000 - £40000 Per Annum Excellent benefits: Clearwater People Solutions Ltd:...

Day In a Page

Wilko Johnson, now the bad news: musician splits with manager after police investigate assault claims

Wilko Johnson, now the bad news

Former Dr Feelgood splits with manager after police investigate assault claims
Mark Udall: The Democrat Senator with a fight on his hands ahead of the US midterm elections

Mark Udall: The Democrat Senator with a fight on his hands

The Senator for Colorado is for gay rights, for abortion rights – and in the Republicans’ sights as they threaten to take control of the Senate next month
New discoveries show more contact between far-flung prehistoric humans than had been thought

New discoveries show more contact between far-flung prehistoric humans than had been thought

Evidence found of contact between Easter Islanders and South America
Cerys Matthews reveals how her uncle taped 150 interviews for a biography of Dylan Thomas

Cerys Matthews on Dylan Thomas

The singer reveals how her uncle taped 150 interviews for a biography of the famous Welsh poet
DIY is not fun and we've finally realised this as a nation

Homebase closures: 'DIY is not fun'

Homebase has announced the closure of one in four of its stores. Nick Harding, who never did know his awl from his elbow, is glad to see the back of DIY
The Battle of the Five Armies: Air New Zealand releases new Hobbit-inspired in-flight video

Air New Zealand's wizard in-flight video

The airline has released a new Hobbit-inspired clip dubbed "The most epic safety video ever made"
Pumpkin spice is the flavour of the month - but can you stomach the sweetness?

Pumpkin spice is the flavour of the month

The combination of cinnamon, clove, nutmeg (and no actual pumpkin), now flavours everything from lattes to cream cheese in the US
11 best sonic skincare brushes

11 best sonic skincare brushes

Forget the flannel - take skincare to the next level by using your favourite cleanser with a sonic facial brush
Paul Scholes column: I'm not worried about Manchester United's defence - Chelsea test can be the making of Phil Jones and Marcos Rojo

Paul Scholes column

I'm not worried about Manchester United's defence - Chelsea test can be the making of Jones and Rojo
Frank Warren: Boxing has its problems but in all my time I've never seen a crooked fight

Frank Warren: Boxing has its problems but in all my time I've never seen a crooked fight

While other sports are stalked by corruption, we are an easy target for the critics
Jamie Roberts exclusive interview: 'I'm a man of my word – I'll stay in Paris'

Jamie Roberts: 'I'm a man of my word – I'll stay in Paris'

Wales centre says he’s not coming home but is looking to establish himself at Racing Métro
How could three tourists have been battered within an inch of their lives by a burglar in a plush London hotel?

A crime that reveals London's dark heart

How could three tourists have been battered within an inch of their lives by a burglar in a plush London hotel?
Meet 'Porridge' and 'Vampire': Chinese state TV is offering advice for citizens picking a Western moniker

Lost in translation: Western monikers

Chinese state TV is offering advice for citizens picking a Western moniker. Simon Usborne, who met a 'Porridge' and a 'Vampire' while in China, can see the problem
Handy hacks that make life easier: New book reveals how to rid your inbox of spam, protect your passwords and amplify your iPhone

Handy hacks that make life easier

New book reveals how to rid your email inbox of spam, protect your passwords and amplify your iPhone with a loo-roll
KidZania lets children try their hands at being a firefighter, doctor or factory worker for the day

KidZania: It's a small world

The new 'educational entertainment experience' in London's Shepherd's Bush will allow children to try out the jobs that are usually undertaken by adults, including firefighter, doctor or factory worker