Biologist David Bowman knew he was going to kick up a jumbo-sized storm with his latest idea for saving Australia's fragile north, and he was right.

Bowman, professor of environmental change biology at the University of Tasmania, believes "mega-herbivores" including elephants, Komodo dragons and rhinoceroses should be introduced to control the introduced African gamba grass that is choking the Outback and creating tinder for fires the size of his home state.

"The idea of introducing elephants may seem absurd, but the only other methods likely to control gamba grass involve using chemicals or physically clearing the land, which would destroy the habitat," he wrote in Nature.

But in a country struggling to deal with millions of introduced feral animals, from foxes, rabbits and the unstoppable cane toad to camels, goats, pigs and water buffalo, the mere thought of letting elephants or rhinos loose alarms other scientists and environmentalists.


"Unmanaged fire and invasive pests are some of the biggest threats to the native plants and animals of the Outback, but ... the last thing our unique landscape needs is the equivalent of a 10-tonne cane toad flattening the countryside," Patrick O'Leary from the Pew Environment Group said.

Australian National University environmental researcher Patricia Warner described elephants as "tree terrorists".

And Dr Ricky Spencer of University of Western Sydney's Native and Pest Animal Unit said: "If we did go down that road of introducing elephants to Australia, we had better develop the technology to clone sabre-tooth tigers to eventually control the elephants."

But Australian National University research fellow Don Driscoll told the ABC Australia should consider elephants.

He said that while the idea might prove to be completely mad, scientists needed to shuck off prejudices, look carefully at costs and impacts, and compare them with other management approaches.

Bowman argues that it is time to canvass "the full spectrum of options ... in an open and honest way".

"I'm being as provocative as possible to try and wake everybody up to say, 'Look, what is currently happening is not sustainable. We have to think outside the square," he told the ABC. "It might be a stupid idea, but is having a world-famous, out-of-control grass-fire cycle a clever idea?"

Bowman said past mistakes needed confronting with solutions based on science rather than emotion or cultural prejudice that, for example, allowed donkeys and camels to be shot - but not horses.