Reporter: Tara Brown
Producer: Phil Goyen
They're cute, cuddly, a national treasure, a must-see tourist attraction. In fact, they earn us a billion dollars every year.
What would Australia be like without koalas?
Well, very soon we might find out.
We all know their habitats are being wiped out by urban development.
That's bad enough but now there's another, even deadlier threat. A virus that acts just like HIV Aids, and sadly has the same results.
So far, scientists are in the dark, there's no vaccine, certainly no cure.
But, there is one sanctuary, one place where koalas are safe, from man, predators and disease.
Special features:
BLOG: Tara Brown reveals how a killer disease could wipe out the koalas.
Full transcript:
INTRODUCTION TARA BROWN: They're cute, cuddly, a national treasure, a must-see tourist attraction. In fact, they earn us $1 billion every year. What would Australia be like without koalas? Well, very soon we might find out. We all know their habitats are being wiped out by urban development. That's bad enough, but now there's another even deadlier threat. A virus that acts just like HIV AIDS, and, sadly, has the same results. So far, scientists are in the dark - there's no vaccine, certainly no cure. But, there is one sanctuary, one place, where koalas are safe, from man, predators and disease.
STORY TARA BROWN: Here on Queensland's Sunshine Coast, we are hunting down a killer. We have spotted a mother and her baby, and chances are, in this part of Australia, they are already suffering a deadly disease that is wiping out our national icon. I am here with veterinary scientist Jon Hanger, the man who discovered the Aids-like virus which is now sweeping through our koala population. Poor little thing.
JON HANGER: Whether it is killing them at nine months, or eight years of age, it is certainly having a major impact on the population and it is just a disaster.
TARA BROWN: For this pair, the prognosis is good. There is no sign of any virus-related disease.
JON HANGER: Just from handling them, too, I can tell they're in good body condition both the mother and the joey.
TARA BROWN: Hey, we're not here to hurt you. But they are two of the lucky ones. In south-east Queensland the koala population has been decimated by the virus. Known as Koala Immune Deficiency Syndrome, or KIDS. Just to get some context, is it as a devastating as HIV AIDS in the human population?
JON HANGER: It is worse. It is worse. I would argue that based on the admissions to our hospital, probably 50% or more of koalas, if they do not get hit by a car, killed by a bulldozer, attacked by dogs, are probably going to die of koala retro virus-related disease, prematurely. So, yes it is worse than HIV, the impact I think is worse than HIV.
TARA BROWN: So, how many koalas do you get through the place?
JON HANGER: We get about 600 koalas every year.
TARA BROWN: This disease is what is called a retro virus. And like AIDS in humans, it weakens the koalas' immune system, making them susceptible to cancer and other fatal illnesses. And, like AIDS, there is no vaccine and no cure.
JON HANGER: I wonder if she had a little bit of mild spinal issue?
TARA BROWN: Jon Hanger runs the koala ward at Australia Zoo's Wildlife Hospital. Many of his patients, like 'Lucky Grills' are victims of car accidents.
JON HANGER: She did not realise that she had struck the koala, until about 12 kilometres on, when an employee at the railway station where she had just pulled up at said, "Hey, did you know, you have a koala on the grill of your car?"
TARA BROWN: Lucky Grills will soon be released back into the wild, but his future is uncertain as more and more koalas succumb to the virus.
JON HANGER: Unfortunately, as with a lot of the retro virus-related diseases, the koalas do not appear sick until they're really, really sick and falling out of the trees.
TARA BROWN: Most koalas in Australia are carrying the virus, but like human AIDS, it can remain dormant for years. Scientists don't know what causes it to flare up but do know it is spread by koalas coming into contact with each other.
JON HANGER: So, can you see a whole stack of blood cells?
TARA BROWN: And even more worrying, over time it has embedded itself in the DNA so now a koalas are being born with it. I am so good at feeding babies this one has gone to sleep without drinking anything. This close to these defenceless orphans, all you want to do is save them. They're very adorable aren't they? And what are the chances of these two having the retro virus?
JON HANGER: From all the populations in Queensland that we have studied, they all have it. Not only do they have the virus in their genes, so to speak, but they also have the virus actively circulating in their blood.
TARA BROWN: It is a grim picture for an national symbol which has been under pressure for decades as developers take over their habitat.
DEBORAH TABART: We could manage this so much better - 20 million people, one landscape and one animal.
TARA BROWN: For the past 20 years Deborah Tabart the force behind the Australia Koala Foundation, has seen the developers move in and the koalas are die out.
DEBORAH TABART: I have been to places in my 20 years where they used to be koalas and now there are not. That is extinction. Extinction is for ever. So if you lose one here, one here... that is how extinction occurs.
TARA BROWN: And in what sort of time frame in those vulnerable areas?
DEBORAH TABART: In South-East Queensland where I live, I suspect five years.
TARA BROWN: Five years and no koalas?
DEBORAH TABART: Absolutely.
TARA BROWN: What is this land going to be turned into?
DEBORAH TABART: Houses and shopping centres.
TARA BROWN: Here in the hinterland between Brisbane and the Gold Coast it is a developer's dream. In the rush for prime real-estate this bush land, home to hundreds of koalas, is to be flattened. They will be moved to a much smaller area of bush further north.
DEBORAH TABART: My considered judgement is that most of those animals will be dead within six months. It is like taking you out of your house tonight and saying, "We're going to dump you on Mars, and see how you go."
TARA BROWN: Deborah believes the stress we're putting on koala habitats is a factor in the spread of this new AIDS-like a virus.
DEBORAH TABART: There is no question, when you have not good enough nutrition you get sick. But there are dear little animals suffering every day from all sorts of things, and I do not believe we're taking it on board anywhere near enough.
TARA BROWN: And koalas are under massive stress. At the time of European settlement koala habitat almost covered the east coast. Today populations are scattered and isolated. On top of a shrinking habitat the virus could be the final blow, according to the man who found it. As a scientist, when you see that retro virus do you say, "This is the Holy Grail? Or do you think, "What the hell do we do with this?"
JON HANGER: When I found that it was like a eureka moment. Unfortunately, finding that the virus was so widespread in the population - essentially, they all have it - it just completely confounded the issue and made me realise that it was not going to be that simple to battle this virus.
TARA BROWN: As the scientists search for answers, the solution may lie here - Kangaroo Island, off the coast of South Australia, is the last refuge for the country's wild koala population.
BILL HADRILL: What kangaroo Island has that is so very different - it is access to many of the iconic wildlife species.
TARA BROWN: As a National Parks and Wildlife officer here, this is Bill Hadrill's backyard. And his koalas are thriving. It is a good life up there? BILL HADRILL: It is a very good life up there. They are truly unique, there is nothing like them in Australia. They have some fairly loose connections to wombats and other Australian native species but they're on their own. They are a curiosity. There's nothing else like it. It is a bit bizarre really.
TARA BROWN: This place is a bit like Noah's Ark for koalas. 18 were brought here in the 1920s when hunting threatened to wipe out the mainland population. Now there are 16,000, and, so far, their isolation has kept them healthy.
BILL HADRILL: Look, it's Kangaroo Island. We have this beautiful stretch of water between us and the mainland, and it really helps us to remain disease free.
TARA BROWN: Could there be a day if you want to see a koala in Australia you have to come to Kangaroo Island? BILL HADRILL: It might very well be the case. We're not seeing the impact at this stage, so we may be in the fortunate situation of not suffering the impacts that mainland Australia will do.
TARA BROWN: The problem is, the Ark is full. And these healthy, hungry koalas are eating their way through the limited food supply on the island. Turning their favourite eucalyptus trees into ghost gums. Quite literally they're eating themselves out of house and home? BILL HADRILL: Yes, as you can see here there is not a single leaf left on these trees to the point where they are dead.
TARA BROWN: So as much as we like koalas there are just too many of them? BILL HADRILL: Yes.
TARA BROWN: To ease the squeeze, some koalas are already being relocated to South Australia, others are being sterilised. But, ultimately, this place may form the basis of a breeding programme for virus-free koalas to boost the ailing mainland population. Breathing space until a scientific solution can be found. Is it just too much, to big? JON HANGER: I would not say that, but it needs a lot more work. You can imagine how many millions, probably billions of dollars, have been spent researching HIV and AIDS in humans. We still do not have a cure for it, or a vaccine. To be arrogant enough to think that we can lick this thing with a few hundreds of thousands of dollars is wishful thinking.
TARA BROWN: Come on, why don't you want to drink? You just want to check out little Molly over there. Disappearing habitats and deadly disease - this admirable national icon is facing a world of problems. But with people like Jon Hanger on their side, these little orphans just may have a future. You cannot grow up to be a big healthy koala if you don't drink. Is it too late to save the koala? JON HANGER: I guess it is horrible to think that we might be past the tipping point with koalas, but there are so many things that make us are very worried about that that I think it is probably overly optimistic to say, "No, we can have this thing licked."
