Image copyright SPL Image caption Not a common sight in the forests of New South Wales - yet

An Australian biology professor is causing a rumble in the academic jungle by suggesting that his country should import elephants and other foreign species into its wild interior.

Rhinos and even giant Komodo dragon lizards could be imported, David Bowman suggests in an article in Nature.

He says Australia is just not managing its most pressing ecological problems, and something radical is needed.

But some fellow scientists say it is just a bad and dangerous idea.

Others, however, are supportive, seeing potential for helping beleaguered Aboriginal communities and reducing the risk of forest fires, as repairing some damaged ecology.

The problems Prof Bowman proposes solving with his radical zoological armoury stem from the huge changes wrought by the two waves of human arrival - the first by forebears of the Aborigines about 50,000 years ago, and the second by European settlers a few hundred years ago.

The first initiated the slow demise of the spectacular megafauna that once bestrode the giant continent.

Image copyright SPL Image caption The Dromornidae family encompassed possibly the biggest bird ever, at 3m high

They included the marsupial lion, a metre and a half long and a powerful predator; the diprotodon, a wombat bigger than a cow; giant birds such as the Dromornidae family that once boasted Stirton's Thunder Bird, three metres high; and crocodiles, lizards and turtles bigger than any still walking this Earth.

Take so many big species out of an ecosystem, and there are bound to be changes all the way down to its bottom.

If you throw in land clearance across enormous swathes of the continent and the subsequent introduction of rabbits, camels, cane toads, rats, pigs and everything else that came with the European settlers, you have an ecology in profound turmoil.

Attempts have been made to control rabbits, pigs, buffalo and lots of other alien species; but they haven't really worked.

"We have a very unbalanced ecology and it's all just spiralling into a trajectory," lamented Prof Bowman when I spoke to him earlier in the week.

"We're not managing actively, we're just managing bits of the problem - so it's a big mess."

So the root of his idea is that if you can't restore the animals themselves, bring in something that can fulfil a similar ecological role.

Grassed up

What's on his mind particularly is gamba grass, an African species growing up to 4m tall that's been introduced into Queensland and the Northern Territory.

The Queensland government lists it as a "pest plant", as it's out-competing native varieties and also raises the risk of fires - a hazard that causes huge damage routinely in many parts of Australia.

Image copyright SPL Image caption Camels have their uses in Australia, but could be targeted by Aboriginal hunters with state support

Machines and herbicides could be used to control it, and have been in some places - but not enough to stop its advance.

Growing so big, mature gamba grass is beyond the grazing capacity of any animal currently in Australia, whether native kangaroos or introduced cattle.

But it wouldn't be beyond a really big herbivore like an elephant.

"Imagine bringing in an elephant with a GPS collar on and sterile, so you know where it is all the time and it can't reproduce," he says.

"So I'm not saying 'let's randomly get animals and throw them into Australia', because strangely enough that's what Australians have done.

"I'm trying to say 'let's imagine that we're going to be more co-ordinated and more intelligent about it - where would you start on that process?'"

Deliberate introductions could even help preserve species that are set to go extinct in other more densely-populated parts of the world, he says.

Dingo dealing

Prof Bowman's vision isn't only about introducing novel species. He's also keen to restore those that still exist to something like their original ecological role.

If we did go down the road of introducing elephants to Australia, we had better develop the technology to clone sabre-tooth tigers to eventually control the elephants Ricky Spencer, University of Western Sydney

So the dingo culling programmes instigated by sheep farmers should be ended, he feels, and the animals encouraged back into areas where they've been wiped out.

Studies show this could benefit native small mammals.

The irony here, of course, is that the dingo isn't truly ancestral, having been brought over from Asia relatively recently - probably just a few thousand years ago.

The proposals contain a strongly social aspect too, in that Aboriginal communities could be empowered to hunt some of the large animals that could be introduced.

They could also be tasked with carrying out controlled burning of forests and grasslands in order to reduce the ever-present fire risk.

"The answer is hiring Aboriginal people who are disadvantaged, who want to spend time in the bush, and get them to do burning and hunting," he says.

"And ok it might cost a lot of money, but it's also a health intervention, because it's been discovered that Aboriginal people, who have shocking health status - their health improves fantastically when they do outdoor work.

"The health stats are a blot on our reputation internationally, there's so much disadvantage, and Australians do want to improve that, and this is one of those rare situations where everyone can get a win."

Even without elephants or Komodo dragons, he believes there's no reason why Aboriginal hunters shouldn't be encouraged and even funded right now to tackle camels.

On the table

So what's provoked the positive and negative comments that have come in on these ideas?

"His comments are careless given recent proposals for the establishment of game reserves in New South Wales and introduction of new potential feral animals into these reserves," says Dr Ricky Spencer from the Native and Pest Animal Unit at the University of Western Sydney.

Image copyright SPL Image caption The Komodo dragon may be a "step too far", says Prof Bowman

"If we did go down the road of introducing elephants to Australia, we had better develop the technology to clone sabre-tooth tigers to eventually control the elephants."

Given Australia's difficult hisory of disastrous species introductions, you'd think some academics would slam the idea simply on the basis that you shouldn't do any more of them - and this was a point picked up by Prof Patricia Werner from the Australian National University (ANU).

"Are we in Australia prepared to try yet another landscape-scale experiment as we did with foxes, rabbits, etc, and merely hope that the elephants don't find our native Australian trees tasty?" she asks.

"There are countless studies in Africa showing that when elephants are removed from an area, tree cover increases. Can we somehow command them to eat only introduced African grasses?"

However, her ANU colleague Dr Don Driscoll says it's right to acknowledge that Australian ecosystems are in a dire state.

"Because of this ongoing environmental catastrophe, we need to put all of the management options on the table to try to find ways of reducing the rate at which our biodiversity succumbs to the impacts of invasive alien species," he says.

"We should therefore consider introducing elephants and rhinoceros to Australia. We should also reconsider widely implemented practices such as culling dingos or burning forests to reduce fuels in southern Australia as an asset-protection measure."

Once these options are put on the table and properly evaluated, he says, some will be accepted and others rejected. He believes that elephants, for example, would not be approved - but the idea should be discussed.

And at the most fundamental level, this is what Prof Bowman is aiming for - to raise the severity of the ecological decline, and get people to think outside the accepted boxes.

"We're not talking about turning up with a barge and unleashing a whole lot of animals and watching the show - that's already happened," he says.

"If people can go through these options carefully and seriously and rule them out and tell me how we're going to manage gamba grass then I'll be very happy; but just to be laughed at and told 'that's a ridiculous idea' - well ok, tell me a good idea."