Gregg Borschmann: If there's a war against cats, feral cats, in Australia, then French Island in Victoria's Western Port Bay has been on the front line for more than five years.

I'm just arriving at the island's Tankerton Jetty, after the short ferry trip from Stony Point on the Mornington Peninsula. The talk on board has been all about feral cats. And, like the tribal passions of football, opinions are still divided.

Ferry passenger 1: But it's true, some people love 'em and some people don't, there are real animal lovers…

Ferry passenger 2: People hate cats, I like cats, you know, that's the problem.

Ferry passenger 1: I don't mind cats either as a pet…

Ferry passenger 2: But we hate Geelong! [laughs]

Gregg Borschmann: Hello, I'm Gregg Borschmann and this is Background Briefing on RN. I'm on a journey to the 'killing fields' of French Island to meet wildlife ranger David Stephenson, and contract shooter and trapper, Vaughn Thompson.

One of Victoria's prized parks, more than 850 feral cats have been trapped and shot dead on the island since 2009. After more than two centuries of being 'off the biological radar', scientists have now confirmed that the feral cat is the biggest single threat driving the second great extinction wave that's sweeping across Australia. Rolling across northern tropical Australia over the past two decades, it's now reached the Kimberley, Australia's last great ark of pre-European biodiversity.

Adding to the losses, the feral cat is now also heavily implicated in the first extinction wave that started with white settlement. On the mainland and offshore islands, across every single ecological niche from the arid lands to our World Heritage rainforests, it's mopping up the remnants of Australia's rich and unique biodiversity.

Leaving Tankerton Jetty on French Island, we head across grazing country on bumpy bush tracks for ranger David Stephenson's office.

David Stephenson: I've always loved cats, I grew up with cats. I've probably in the last five years shot about 800 of them, and I do it because I'm trying to protect the wildlife. I don't enjoy doing it, and I try and do it as efficiently as I possibly can, with a single shot with a .22.

Gregg Borschmann: Apart from the cats, David Stephenson has got other problems as well. He's lucky there's no foxes on the island, and over the past eight years he's eliminated the feral pigs.

But there's a long list of other pests he's flat out trying to control; wild populations of goats, feral peacocks, rabbits, and the massive samba deer. Despite this, on French Island the feral cat is king. David Stephenson knows that it's the most threatening predator.

David Stephenson: If you go around the island today and you'll see there's Cape Barren geese everywhere, there's young everywhere, we've seen cats work as like a pride of lions on Cape Barren geese, they'll work as a pack. They're really little lions, they behave like a pride of lions. They do very similar things that lions do. You know, when a male takes over a territory it will kill the cubs. When you skin a cat you'll see you've got all these scent glands under their lip, and under their paws, just like lions, just like tigers, just like all the rest of the big cats.

Gregg Borschmann: Just over 100 people live on French Island, and most of them own cats. David Stephenson reckons he's only just 'keeping the lid' on a wild population of more than 500, so that's more cats than people.

Across every state and territory, it's a similar story. An estimated 15- to 23 million feral cats call Australia home. Scientifically, they're the same species as the domestic cat, Felis catus. But ultimately they're all descendants of the wild cats of Africa and Asia. And unlike domestic cat, which is a fussy eater, these cats will eat almost anything.

Ecologist Dr John Read has dissected the gut of almost a thousand feral cats that he's caught over the past 25 years in the South Australian arid lands.

John Read: Each one is a bit of a surprise, you never really know what you're going to get. We actually find that they're quite a useful technique for finding out what's living in the area, a very good supplement to standard observations and trapping and things like that. You feel a little bit like opening your Christmas presents, except there's more surprise in this than some of the Christmas presents we get.

Just earlier this year I was cutting open some cats. Some of them had large snakes, King Brown snakes probably about four-foot long, juvenile perenties which are the largest lizard in Australia, the big goannas. They eat falcons and cockatoos, bats, centipedes, scorpions. I imagine that they would have a hard time pulling down a saltwater crocodile, I imagine cassowaries are probably pretty safe. But virtually every lizard, every snake, every frog, every bat, just about every bird in Australia and any mammal smaller than a large kangaroo, at least when they are joeys, are all susceptible to cat predation.

Gregg Borschmann: Few know Australian mammals better than conservation biologist Dr John Woinarksi. He's just co-written an important State of the Nation report for the mammals.

It's well known that Australia has the world's worst record for extinctions. Since European settlement, at least 29, possibly 30 mammal species have been pushed off the evolutionary gangplank.

John Woinarksi: Australian mammals have suffered a terrible crisis over the last 200 years, probably a greater rate of extinction than any other group of animals in the world over that time period. Many of these mammal species have been wiped out or declined for a range of reasons, but our assessment was clearly that the major cause of decline and extinction has been predation and particularly predation by feral cats.

Gregg Borschmann: Scientists thought for many years that the extinction wave caused by white settlement had petered out some time in the 1960s, more or less stopping at Australia's tropical margins. But recently, that belief has been shattered.

John Woinarksi: Australian mammals did suffer a wave of extinctions initially in semi-arid then arid Australia leading up to about the 1960s, and we thought that might be the end of the problem but in fact over the last two to three decades in northern Australia, the same sorts of species that went extinct elsewhere in Australia seem to be disappearing rapidly from that northern Australian landscape as well.

Gregg Borschmann: Almost 30 years ago and not long out of university, John Woinarski went to work in what was then a living biological ark, the top end of the Northern Territory, places like Kakadu and Arnhem Land. It was a wonderland.

John Woinarksi: Northern Australia for ecologists offered a sort of time travel experience, we could see Australia as it must have been 200 years ago. So when I went there in the late 1980s we did lots of wildlife survey, and we'd go out, put a lot of traps for mammals and in the morning go and clear those traps, and it was really laborious because we were catching so many animals, so many different species of animals and so many numbers of each of those animals that it was…you know, it was effectively a paradise for a zoologist.

And then over the course of a decade we were getting less and less in our traps. until I guess by about 2000, 2010, that sort of era, we were coming back with almost nothing. This was in areas that were remote from any obvious threats, in Kakadu, in Arnhem Land and places like that. And it was demoralising, right on the cusp of a sort of major almost extinction event I guess, a decline of really severe and really rapid rate.

Gregg Borschmann: So why the sudden and recent collapse? It's long been thought that cats have been in Australia for more than 400 years, cast-offs from Dutch and Portuguese shipwrecks along the West Australian coast.

But Chris Johnson, Professor of Zoology at the University of Tasmania, says we now know that's not true.

Chris Johnson: It's now quite clear the cats are a recent arrival, they came in with the British from about 1820 onwards, but established very quickly over all of the continent. And there is some evidence, and again we are only just coming to grips with this, that lots of species disappeared very, very early in the history of the colonisation of Australia by the British. There are mammal species that have only just been described and we realise that they must have been abundant 200 years ago, but then vanished. So what caused them to vanish? And the leading candidate for that cause I think is the feral cat.

Gregg Borschmann: So it's only in past decade or two that researchers have come to a radical re-writing of the ecological story

Scientists like John Woinarksi say we overlooked the feral cat because we're still struggling to understand the Australian landscape, especially in the tropical north.

John Woinarksi: It seemed as if these landscapes were intact, so there were no obvious threats. We knew that feral cats had been in those environments for maybe 100 years or so, so it didn't seem they were an obvious culprit to cause such rapid and severe declines, you know, just in the last decade or two. So it wasn't until we started modelling the rates of mortality, trying to tease apart the impacts of all the other potential causes—including fire, including weeds, including feral buffalo and things like that—that we were left really with one major culprit, and that turns out to be the cat.

Gregg Borschmann: But the problem is not just the feral cat. We've also discovered only recently that the cat lives in an uneasy alliance, or contest, with the European red fox. Dr Chris Johnson again:

Chris Johnson: As we've got better at controlling the impact of foxes, in a sense that has unmasked the feral cat as a threat, and part of the reason there is that foxes are actually really good at controlling cats, you know, they're aggressive to them and they control their numbers, and cats avoid foxes. So where you have got a lot of foxes you tend not to have that many cats, and it looks like foxes are a big problem, and of course they are, but if we managed to knock the foxes down, the cats can come up, so in a sense we solve one problem and buy another problem.

Gregg Borschmann: That ecological lesson, a sobering real-life cat and fox story, played out recently in Western Australia. From the mid-1990s, as part of a biodiversity project called Western Shield, almost a million fox baits were dropped by plane every year across public lands in the south-west of the state. There was a big knock-down of foxes and an immediate resurgence of native birds and mammals like the tammar wallaby, the critically endangered brush tailed bettong, or woylie, and the western ground parrot. The woylie was removed from state, national and international threatened species lists.

Then, inexplicably, things went wrong. From the early 2000s, spectacular population crashes—in some cases over 90%—were recorded.

Dave Algar is the senior research scientist developing cat control strategies for the WA Department of Parks and Wildlife.

Dave Algar: The school is still out on how it happened. I mean, one school of thought is that implementing fox control, broad-scale fox control allowed these native species to build up in numbers, which then allowed better survival of the cat population and then they became a threat.

Gregg Borschmann: As hunters, cats prefer live prey, so it's been the holy grail of feral cat management to develop a bait that's enticing, humane and lethal. So far, a cat bait called Eradicat is the best shot in the locker.

Dave Algar again:

Dave Algar: Eradicat is the feral cat bait we use in Western Australia. It's essentially a chipolata sausage comprised of kangaroo meat and it's got lots of flavour enhancers that make it particularly attractive to cats. It contains 4.5 mgs of sodium monofluoroacetate, which is a toxicant, and we're finding it very beneficial for the control of feral cats in this state.

Gregg Borschmann: The catch is, Eradicat can only be used in WA.

Most native animals in other parts of Australia will die from the 1080 poison it uses. In the west, animals there have adapted to it, as it's found naturally in pea plants in the Gastrolobium genus, which is why, back on French Island, ranger David Stephenson and contractor Vaughn Thomson are still shooting and trapping.

As we poured over maps and reports in his office, David Stephenson explained the secret ingredient in the live traps that he uses; KFC chicken. It even proved irresistible to the native rats and mice of French Island when their numbers boomed after the breaking of the last drought.

David Stephenson: You've basically got a live bait, because the mice were hanging off the bait, so they've got a big piece of chicken, we use KFC for bait. We've trialled everything from pilchard to rabbit to all sorts of fish, actual cat food, you name it, we've tried it, and we stick with KFC because it lasts so long in the field, and it smells so much too, so it puts an aroma out there. Even the motto for KFC now is 'smell the chicken'.

Gregg Borschmann: And it's got to be fresh?

David Stephenson: It's got to be fresh, yeah. I've trialled using frozen chicken before, KFC. Not as successful. So it needs to be fresh, and even sometimes you can heat it on the bonnet of the car, like on the manifold. You just pull up, put it in some alfoil and put it on the manifold, just to get it, yeah, warm and create a bit of scent.

Gregg Borschmann: In the late afternoon of my first day on the island, I joined David Stephenson and Vaughn Thompson on the trap run. There's around 100 cat traps, and they're easy to spot as we move along fence lines and tracks. Vaughn had 20 buckets of KFC to freshen up the bait in each trap.

Vaughn Thompson: We're just on the west coast of French Island, just on a walking track, because cats like using tracks, open roads, that's why people do see 'em. So we're just going to change the bait here because the rain affected it, when we had a little bit of rain last night so…

Gregg Borschmann: So you've got a nice fresh piece of chicken?

Vaughn Thompson: A nice fresh bit of chicken. As you can see on my gloves, it's very oily. I can't really eat this anymore after doing this for the last few years, it doesn't really go down too well.

Gregg Borschmann: And you've just got that hanging there?

Vaughn Thompson: Yes, swinging in front of it, so it's like a visual, so yeah.

Gregg Borschmann: So the windier the better?

Vaughn Thompson: Well, you could that way, yes, that's right, if it didn't have the rain with it.

Gregg Borschmann: So what are you now, you're setting it?

Vaughn Thompson: Yes, just hanging the bait, hopefully present it good enough for the cat to come along, if there is any around.

Gregg Borschmann: Well, that's the first trap and it's empty, so zero out of one so far, Vaughn.

Vaughn Thompson: That's right, I've even checked a few this morning and I've had no luck, so hopefully this last run we do, hopefully we can get one little feline anyway.

Gregg Borschmann: While French Island is still pretty much ecologically intact and the cats are controlled, in the Channel Country of western Queensland, it's a different story. Feral cats have all but wiped out the last remaining Queensland stronghold in the wild of the endangered greater bilby. It's now famous as Australia's Easter Bunny.

Frank Manthey is the co-founder of the Save the Bilby Fund. He witnessed a feral cat plague on the Diamantina floodplain there in the early 1990s.

Frank Manthey: There's a guy that did some research on the letter-winged kite who went out to exactly where the bilbies are. And he described the tree with the spotlight as a Xmas tree, there was that many eyes shining the lights from the cats in that tree. And when I actually got out there to that area, I actually took the army out there and when we'd go down these drainage lines, every letter-winged kite nest had at least four or five feral cats asleep in the nest and of course the birds and eggs and things had long gone and I thought to myself 'What a disgusting way that we are treating this country'.

Gregg Borschmann: That's unbelievable, because presumably the young of those hawks, those kites would have been predated by those cats. So first they ate them, then they stole their nests.

Frank Manthey: Exactly, and they would sleep there all day and of course then come down onto the plains to destroy our native wildlife.

Gregg Borschmann: The Queensland government has declared what it calls a 'war' on the feral cat in the area. Frank Manthey says it's partly because he's been able to infect the Premier Campbell Newman with 'bilby fever'.

But despite an expensive shooting program over the past two years at the Astrebla Downs National Park, the wild bilby population is still being decimated. By March this year, the stomachs of more than 3,000 shot cats had been dissected to reveal at least 120 bilbies, and countless other native species. It's speculated that there may now be as few as 200 bilbies surviving in the wild.

So I asked the Queensland Minister for Environment and Heritage Protection Andrew Powell, do we know precisely how many bilbies are left?

Andrew Powell: Look we don't Gregg, but the estimates of several hundred is probably pretty close to the money. What we have seen out at Astrebla Downs is what could only be called a feral cat plague. We have done a fair bit of work over the last two years as a government to try and drive that down. In two years our Queensland Parks and Wildlife Service rangers have removed around 3,000 feral cats in that part of the world alone.

Gregg Borschmann: This has cost you $350,000 over those two years. The bilby is listed nationally as threatened, yet the federal government contributed nothing. Has Queensland and the bilby been let down or short-changed by the Commonwealth?

Andrew Powell: I think as a state we will always continue to do what we need to do to ensure our threatened species like the bilby are protected and conserved as best we can. And obviously any additional funds that can come from the federal government would be welcomed.

Gregg Borschmann: But spending $350,000 every couple of years is not financial sustainable is it…

Andrew Powell: No, it's not…

Gregg Borschmann: …even with the support of Cabinet and Premier Newman. What we have seen is basically a one­-off, isn't it?

Andrew Powell: We've seen a persistent campaign by this government to tackle feral cats. But you're right, prevention is always better than a cure.

Gregg Borschmann: The problem is, there is no cure. One issue is the confused regulatory status of the feral cat. It is, if you'll excuse the pun, a dog's breakfast.

Frank Manthey from the Save the Bilby Fund wants it on the agenda at a national summit.

The feral cat is listed as a key threatening process under the Federal Environment Protection and Biodiversity Conservation Act. But it's still not declared a pest species in Victoria, South Australia, West Australia or Tasmania. Simply, the cat is an environmental threat, but it's not an agricultural pest, and that means it gets less money for research.

Frank Manthey again:

Frank Manthey: It's because it doesn't affect humans, number one. Look, when the Hendra virus started, we lost some humans because of that bat and the Hendra virus, they threw everything in the book to fix that and get an antidote and whatever. And rightly so, I'm not saying that that's wrong. But what I'm saying is we've got a whole heap of species about to go down the gurgler because of a cat and we throw nothing at it, you know, we're not even throwing stones at it. Everybody is happy to sit back and let it happen.

Gregg Borschmann: Since the election of the Abbott government, Federal Environment Minister Greg Hunt has elevated feral cats and threatened species recovery to what he calls a 'front and centre priority'. And he now has a plan for a 10-year plan to eradicate feral cats.

Greg Hunt: Well, I would like to see that within a decade we have effectively eradicated all of the significant populations of feral cats around Australia. I wouldn't promise that there are no feral cats. I think that would be not credible. But I think we can effectively remove the threat to our native population if we have a decade-long plan.

Gregg Borschmann: The Minister says he'll host a national threatened species and feral animals summit before July next year. And it's there that he wants everyone to sign onto his 10-year national plan. So how does he imagine it may work?

Greg Hunt: The cat bait is something which within a very short period of time we can deploy on a very major basis. It's about the first big hit to that feral cat population. The second wave is about the trapping and hunting on a massive scale. At the moment we can do that in small areas. And then the third wave is if it were 100% safe, and in my view not until it is absolutely guaranteed with external assessment, then you could have a biological control. The research is already underway. But we just have to sure that we don't let loose in our natural environment something with unintended consequences.

Gregg Borschmann: The Environment Minister has made three very big and potentially expensive promises here, and the problem is, as usual, money, or lack of. First up, the cat bait Curiosity. Since 2008, $2.2 million has been spent by the federal government on feral cat research and control. Nearly 80% of that went on developing Curiosity. It's the one the government's pinning its hopes on.

Greg Hunt again:

Greg Hunt: This is a bait which is designed to exclude almost every other possible predator of the bait. It's a very, very carefully constructed bait. It has a toxin which simply works by putting the animal to sleep, and the way it operates if it is seeded and placed on a very large scale in those areas where the cats congregate, then we will be able to begin a pathway to eradicating feral cats in significant areas and then to thinning them out in other areas. The Curiosity cat bait is something which I have made a national environmental cause and research priority.

Gregg Borschmann: Despite the Minister's enthusiasm, we still don't know if it works.

Andrew Cox is CEO of the Invasive Species Council.

Andrew Cox: Certainly Curiosity bait has got a long way to go to be confident that it is going to work, and that's part of the danger in relying so heavily on it. So the research is already showing some impacts on non-target species like goannas, so that effectively rules it out in northern Australia but in southern Australia where they hibernate in winter then we might be able to use it in those southern states. And some of the research in WA is also showing that are some impacts particularly on dingoes but maybe on some of the native birds as well. We need to be confident that it's not going to have too many unintended consequences for the benefit it could deliver.

Gregg Borschmann: So what you're saying is that there's no guarantee that Curiosity will ever get out of the starting blocks?

Andrew Cox: There's no guarantees with biological controls and new baits, you can't put all your eggs in one basket, you need to have a broad investment in a range of biological controls and new baits. I am a bit surprised to see so much investment so far in that one bait, and to hear the government only talking about that as a solution when we still aren't confident it's going to be the solution, and that is why broad investment is necessary.

Gregg Borschmann: Background Briefing has confirmed that questions have been raised in recent studies about the impact of the Curiosity bait on non-target species. These include the two most recent field trials, at Roxby Downs in South Australia and another in the Pilbara region of WA.

We put the issues raised in the studies to Federal Threatened Species Commissioner Gregory Andrews.

Gregory Andrews: So Gregg, I'm not aware of that study and I'd like to learn more about it, and I'm very conscious that we need to make sure that this bait, that will be one part of a broader toolkit, is safe. So both of those studies you are referring to, I'm really interested in learning more about them. They haven't been brought to my attention to yet.

Gregg Borschmann: I pointed out to Gregory Andrews that these studies were funded by the Department of Environment and on their website.

Gregory Andrews: Yes, they're trials and the trials are on-going. So if this was a commercially available bait that was being used widely across Australia now then I would be very concerned. Because it's a trial, what I am most interested in is learning the lessons, and you're telling me of two examples of where testing has been associated with declines in other species. From what I'm hearing they are not declines in threatened species but they are still declines in Australian species, so I'm interested in that, learning more about it and following up on it.

Gregg Borschmann: I also asked Gregory Andrews about the recent field trials at Roxby Downs that found a significant reduction in tracked dingo activity after baiting. As Threatened Species Commissioner, did that concern him?

Gregory Andrews: So dingoes are one of the species that need to be managed carefully with the Curiosity feral cat bait. Dingoes and goannas are the species that I am advised that are most affected.

Gregg Borschmann: Greg Hunt's second priority, or 'wave' as he calls it, is to see trapping and hunting rolled out on a 'massive scale'. This will be delivered, in part, by the new Green Army. Greg Hunt says that the design of the army will ensure that threatened species recovery is fundamental. More than $500 million has been committed to the Green Army over the next four years.

Greg Hunt: If a quarter of that on early indications is directed towards threatened species protection and eradication of threats such as the feral cats, that's $125 million over the next four years. After, that $75 million a year. It's very, very, very significant funding, on a quantum scale larger than anything which has been before.

Gregg Borschmann: The Abbott government recently announced the first round of projects funded under the Green Army. Of 197 projects, not one of them specifically mentions the feral cat. But Threatened Species Commissioner Gregory Andrews says that two of the projects will deal with feral cats.

Gregory Andrews: So a quarter of the Green Army applications roughly had a focus on threatened species. In the current round I am advised that at least two of the projects were feral control to allow for greater protection of native mammals and the management of reintroduced species, and both of those projects cites feral cats and foxes as the key threats. If I can give you an example…

Gregg Borschmann: Sorry to interrupt though, Gregory…two projects out of almost several hundred, that's not 25%.

Gregory Andrews: No, actually 25% of the Green Army projects…roughly 25% had a threatened species element.

Gregg Borschmann: But there was no mention…

Gregory Andrews: But feral cats aren't the only driver, and small mammals, which are the main victims of feral cats, as well as lizards, aren't the only threatened species. We have 1,850 threatened species and many of them are plants.

Gregg Borschmann: Background Briefing has confirmed that each Green Army project receives $190,000. So that's two projects, receiving $380,000, and we don't know how much of that will be spent on cat control.

So if so little is happening on the ground, what about biological control?

Dr Andrew Burbidge was a co-author of the Mammal Action Plan that will be used by Greg Hunt as part of his national blueprint for threatened species. Dr Burbidge is a supporter of biological control. But he says it requires a long-term commitment and 'quite a large amount of money', and that's not happening.

Andrew Burbidge: I am not aware of any current research going on in this area at the moment. There was research in the late '80s and '90s but I think that's all. They had a lot of problems, the funding wasn't continued and it is shut down.

Gregg Borschmann: Andrew Burbidge also points to another problem.

Andrew Burbidge: We have looked in Australia at biological control of foxes and rabbits and house mice at various times, particularly in the late '80s and '90s, there was work done within CSIRO, funded by the federal government, to see whether you could develop the idea of immuno-contraception. That is providing some sort of a trigger in an animal that actually makes it sterile.

Gregg Borschmann: Is one of the problems the fear of what might happen if such a virus was developed that it escaped Australia?

Andrew Burbidge: Yes, I think that having a transmissible virus as the vector for immuno-contraception or whatever other technique's available is not really a viable option because the feral cat has been bred from the wild cat of Africa, Europe and Asia, and if that transmissible disease, that virus escaped Australia or was taken out purposely by someone who, you know, wanted to cause problems in another country, then we would have actually have developed a technique for eradicating native animals in other people's countries, and I just think that's not on.

Gregg Borschmann: In other words, one of the dangers of a transmissible virus of this kind is that it could spread beyond Australia and wipe out the wild cat Felis silvestris, from which the domestic cat, Felis catus has evolved.

I'm Gregg Borschmann, you're listening to Background Briefing here on RN, and this is the story of the great extinctions waves and the feral cat.

Greg Hunt hopes to sign everyone up for a 10-year feral cat eradication plan. But Australia effectively already has one. It was written in 1999 and updated as recently as 2008. But it's been on the shelf and begging for funding.

Andrew Cox from the Invasive Species Council says we don't need to re-invent the wheel.

Andrew Cox: We've got a plan that gives a good strategic approach of how to tackle the impacts of cats across Australia on our biodiversity, but unfortunately very little has been implemented. Certainly the federal government has been missing in action in driving the delivery of that plan and there's virtually no funding for its implementation...well, there is none at the moment, there might have been initially. And almost all of the…actually all of the effort from the federal government is now going into the development of the Curiosity bait.

Gregg Borschmann: So it's a plan, but it's not an action plan?

Andrew Cox: It's a plan with actions, but they're not being actioned on.

Gregg Borschmann: Of course, the federal government has placed a great deal of emphasis on 'practical conservation actions'. That's even in the terms of reference for the Threatened Species Commissioner. So it comes as a surprise that in the Kimberley—Australia's last great biological ark, on the frontline of the second extinction wave—that there is no direct action, at least not on public lands. The last baiting for feral cats was done there in the late 1990s.

Dave Algar from the WA Department of Parks and Wildlife again:

Dave Algar: We're not currently doing any feral cat baiting in the Kimberley. We've done some earlier trials back in the late 1990s and showed that the Eradicat bait could successfully control feral cats up there but at this stage we are not conducting any baiting programs in the Kimberley.

Gregg Borschmann: And is that a problem, because that is the hotspot for this second extinction wave, that's where it is all occurring.

Dave Algar: I really couldn't say. I mean, at this stage the furthest north we work is the Pilbara. It's I guess a question of resources to implement strategic baiting programs up there, and unfortunately I couldn't add to that.

Gregg Borschmann: Yes, but you would have to admit that if this is where we are losing a great deal of the existing biodiversity, shouldn't we be there on the front line?

Dave Algar: As a scientist and a researcher, yes, I believe we should, but the available funding for undertaking these projects is limited and there are obviously other areas where it's considered to be important.

Gregg Borschmann: One bright spot is the new federally funded Threatened Species Recovery Hub. It's got annual funding of more than $5 million, but even with Minister Hunt's 'front and centre' promise, we still don't know what the feral cat will get.

Of course, as governments have struggled to maintain funding and research budgets for this work, private groups such as the Australian Wildlife Conservancy, Bush Heritage and the Foundation for Australia's Most Endangered are increasingly cashed up and stepping into the space.

For example, the work of the AWC on Mornington-Marion Downs stations in the Kimberley has confirmed the intertwined nature of the threat posed by feral cats, fire and grazing pressure. Latest research with sniffer dogs tracking cats shows that the ferals pose the greatest threat to native species after intense ground fires.

So what chance do we have of ever ridding Australia of the feral cat?

Dave Algar: The eradication on the mainland is unlikely to work. Eradication is really only possible on islands.

Gregg Borschmann: Why is that, what's the problem? Why is eradication on the mainland a pipedream?

Dave Algar: Essentially, you target specific areas, you try to be strategic but obviously then you have dispersal into that site following your initial baiting program. So it's an on-going control measure.

Gregg Borschmann: So is it a matter of cost, is it a matter of technology, why couldn't we eradicate on the mainland?

Dave Algar: I don't believe you've got the opportunity to eradicate on the mainland, there's several problems there. I mean, Australia is so vast, the cost would be astronomic to bait the entire continent, and you've still got the ongoing problem of domestic pets getting into the stray population and then into the feral cat population. Until legislation works through that all cats must be de-sexed, you're always going to have some sort of recruitment into that feral population.

Gregg Borschmann: Back on French Island, on the afternoon of the second day, Vaughn Thompson has finally caught a cat. It's in good nick, sleek and obviously well fed. But it doesn't hiss, spit or even miaow. Only domestic cats learn to do that.

Okay, what have we got?

Vaughn Thompson: It's definitely a tabby, and actually by the smell of it, it stinks from a mile away, I don't know if you can smell that, but it's definitely a male.

Gregg Borschmann: Okay, you've got the gun, what is it?

Vaughn Thompson: It's just a .22 mate, nice and cheap. So, they do the job, they do the job for most things; cats, foxes, rabbits, so yeah…

Sometimes you can't get one in straight away because you can see it running back and forth but…

[shot]

That's game over, instant, as you can tell. Sometimes they might give a little bit of a movement but this one…well 99% of the time they won't, but that it, like this one, as you can tell, hasn't moved at all. Nice and quick and cheap.

Gregg Borschmann: Well, there 15-23 million cats in this country and you've just shot one of them. Do you ever imagine a day when Australia won't have feral cats?

Vaughn Thompson: Oh if they learn a lot more about it they might get down to minimal numbers and hopefully one day nought. But unless people start knowing about it and doing something about it there's going to be twice that many in another 10 years, so yeah, hopefully Australians start getting on board.

Gregg Borschmann: Can you ever imagine a time when there'll be no cats on this island, on French Island?

Vaughn Thompson: Hopefully. I don't know if it's ever going to happen because of…I don't know, funding dries up. I don't know if I'll have a job doing what I like to do, maybe by the end of this year either because of the Parks not getting enough funding for me to do contracts, which is a pity...but hopefully I'll stick to it as long as I can.

Gregg Borschmann: Back at the University of Tasmania, zoologist Professor Chris Johnson says Australia may actually be on the wrong path trying to eradicate the feral cat. Part of his solution is the native dingo.

Chris Johnson: Dingoes might not be the only solution or the complete solution, but they are part of a kind of ecological view of how we could reduce the impact of cats. And if you put a few things together, like a fire regime that doesn't help cats, a population of dingoes that hinders cats and maybe minimal livestock grazing that also means there's plenty of cover on the ground for small mammals to get refuge from predators, then we could allow cats and small mammals to co-exist. And I really think that that's actually the vision we should be aiming for and a really optimistic future that we could try and create.

Gregg Borschmann: Of course, there are other ways the feral cat could be tackled. One controversial idea, so controversial that the Victorian government has commissioned a formal independent risk analysis, is to re-introduce the Tasmanian devil into the Wilson's Promontory National Park.

Chris Johnson again:

Chris Johnson: It's quite possible that the Tasmanian devil could help solve some environmental problems in places like Wilson's Promontory, problems to do with overabundant herbivores and too many feral cats, and red foxes as well. The indications from Tasmania are that the devils could be quite significant in controlling the activity and possibly the numbers of feral cats. And that could be part of the reason that until recently feral cats have not done significant damage to wildlife in Tasmania. There are no extinctions of wildlife in Tasmania that we can blame on the feral cat. So we could create a better functioning ecosystem in places like Wilson's Promontory by putting a large predator like the devil back into that system.

Gregg Borschmann: So how much time do we have? And what's at stake if we don't get this right?

Conservation biologist Dr John Woinarski is blunt.

John Woinarski: The future could well be desolate. We've got one of the most distinctive, rich, endemic and interesting faunas in the world, we are remarkably lucky in that respect. And we have trashed it over the past 200 years, and at the current rate of decline it will continue to be trashed. It's probably another generation or so and we will have lost perhaps half of our mammal fauna.

Gregg Borschmann: Background Briefing's co-ordinating producer is Linda McGinness, technical production by Joe Wallace, research by Nardine Groch, additional research by Anna Whitfeld, the executive producer is Wendy Carlisle, and I'm Gregg Borschmann.