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."

Arts and Entertainment
books
Voices
Caustic she may be, but Joan Rivers is a feminist hero, whether she likes it or not
voicesShe's an inspiration, whether she likes it or not, says Ellen E Jones
Arts and Entertainment
The Doctor and the Dalek meet
tvReview: Doctor Who Into the Dalek more than compensated for last week's nonsensical offering
Sport
Diego Costa
footballEverton 3 Chelsea 6: Diego Costa double has manager purring
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Life and Style
3D printed bump keys can access almost any lock
techSoftware needs photo of lock and not much more
Arts and Entertainment
The 'three chords and the truth gal' performing at the Cornbury Music Festival, Oxford, earlier this summer
music... so how did she become country music's hottest new star?
Life and Style
The spy mistress-general: A lecturer in nutritional therapy in her modern life, Heather Rosa favours a Byzantine look topped off with a squid and a schooner
fashionEurope's biggest steampunk convention heads to Lincoln
News
i100
News
The Digicub app, for young fans
advertisingNSPCC 'extremely concerned'
Arts and Entertainment
Star turns: Montacute House
tv
News
i100Steve Carell selling chicken, Tina Fey selling saving accounts and Steve Colbert selling, um...
Arts and Entertainment
Unsettling perspective: Iraq gave Turner a subject and a voice (stock photo)
booksBrian Turner's new book goes back to the bloody battles he fought in Iraq
News
Dr Alice Roberts in front of a
peopleAlice Roberts talks about her new book on evolution - and why her early TV work drew flak from (mostly male) colleagues
News
i100
Arts and Entertainment
Some of the key words and phrases to remember
booksA user's guide to weasel words
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
iJobs Job Widget
iJobs General

Senior Data Scientist (Data Mining, RSPSS, R, AI, CPLEX, SQL)

£60000 - £70000 per annum + Benefits + Bonus: Harrington Starr: Senior Data Sc...

Law Costs

Highly Attractive Salary: Austen Lloyd: BRISTOL - This is a very unusual law c...

Junior VB.NET Application Developer (ASP.NET, SQL, Graduate)

£28000 - £30000 per annum + Benefits + Bonus: Harrington Starr: Junior VB.NET ...

C# .NET Web Developer (ASP.NET, JavaScript, jQuery, XML, XLST)

£40000 - £50000 per annum + Benefits + Bonus: Harrington Starr: C# .NET Web De...

Day In a Page

The other Mugabe who is lining up for the Zimbabwean presidency

The other Mugabe who is lining up for the Zimbabwean presidency

Wife of President Robert Mugabe appears to have her sights set on succeeding her husband
The model of a gadget launch: Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed

The model of a gadget launch

Cultivate an atmosphere of mystery and excitement to sell stuff people didn't realise they needed
Alice Roberts: She's done pretty well, for a boffin without a beard

She's done pretty well, for a boffin without a beard

Alice Roberts talks about her new book on evolution - and why her early TV work drew flak from (mostly male) colleagues
Get well soon, Joan Rivers - an inspiration, whether she likes it or not

Get well soon, Joan Rivers

She is awful. But she's also wonderful, not in spite of but because of the fact she's forever saying appalling things, argues Ellen E Jones
Doctor Who Into the Dalek review: A classic sci-fi adventure with all the spectacle of a blockbuster

A fresh take on an old foe

Doctor Who Into the Dalek more than compensated for last week's nonsensical offering
Fashion walks away from the celebrity runway show

Fashion walks away from the celebrity runway show

As the collections start, fashion editor Alexander Fury finds video and the internet are proving more attractive
Meet the stars of TV's Wolf Hall... and it's not the cast of the Tudor trilogy

Meet the stars of TV's Wolf Hall...

... and it's not the cast of the Tudor trilogy
Weekend at the Asylum: Europe's biggest steampunk convention heads to Lincoln

Europe's biggest steampunk convention

Jake Wallis Simons discovers how Victorian ray guns and the martial art of biscuit dunking are precisely what the 21st century needs
Don't swallow the tripe – a user's guide to weasel words

Don't swallow the tripe – a user's guide to weasel words

Lying is dangerous and unnecessary. A new book explains the strategies needed to avoid it. John Rentoul on the art of 'uncommunication'
Daddy, who was Richard Attenborough? Was the beloved thespian the last of the cross-generation stars?

Daddy, who was Richard Attenborough?

The atomisation of culture means that few of those we regard as stars are universally loved any more, says DJ Taylor
She's dark, sarcastic, and bashes life in Nowheresville ... so how did Kacey Musgraves become country music's hottest new star?

Kacey Musgraves: Nashville's hottest new star

The singer has two Grammys for her first album under her belt and her celebrity fans include Willie Nelson, Ryan Adams and Katy Perry
American soldier-poet Brian Turner reveals the enduring turmoil that inspired his memoir

Soldier-poet Brian Turner on his new memoir

James Kidd meets the prize-winning writer, whose new memoir takes him back to the bloody battles he fought in Iraq
Aston Villa vs Hull match preview: Villa were not surprised that Ron Vlaar was a World Cup star

Villa were not surprised that Vlaar was a World Cup star

Andi Weimann reveals just how good his Dutch teammate really is
Bill Granger recipes: Our chef ekes out his holiday in Italy with divine, simple salads

Bill Granger's simple Italian salads

Our chef presents his own version of Italian dishes, taking in the flavours and produce that inspired him while he was in the country
The Last Word: Tumbleweed through deserted stands and suites at Wembley

The Last Word: Tumbleweed through deserted stands and suites at Wembley

If supporters begin to close bank accounts, switch broadband suppliers or shun satellite sales, their voices will be heard. It’s time for revolution