Ian Tucker: You suggest that introducing elephants into the Australian ecosystem isn’t such a radical idea as it first sounds?
David Bowman: The Australian ecosystem is in a bad way and ecologists and prehistorians are involved in a big debate about it. We know that about 40,000 years ago, when humans colonized Australia, a large assemblage of animals — marsupials, giant birds and reptiles — became extinct. Imagine deleting all the animals out of the African environment — what you would be left with is an Australian landscape.
IT: Then the Europeans introduced species ...
DB: The Europeans who came to Australia didn’t know about the extinct mega-fauna; all they could see was really good range country. They introduced animals such as sheep and cattle and some of their animals, such as foxes and cats, escaped and became feral. The result is that lots of small native animals are going extinct, but we’ve introduced new animals that are really thriving, such as camels and water buffalo. These introductions were completely ad hoc; there wasn’t ecological engineering — stuff happened.
IT: And the gamba grasses are an alien species, so they require an alien species to control them?
DB: Most of these grasses were introduced when the Australian government had people trying to improve range production. They found this plant in West Africa called gamba grass; they thought: “Beauty! It’s big, it has deep roots and it grows like fury.” They did trials and one thing led to another and it escaped. Weeds often sit and then something happens and they take off. And that takeoff happened with gamba grass during my lifetime in the Northern Territory.
I wrote a piece in 1999 saying that in the next two decades, we’ll know whether this thing will go crazy or not, and it has. Some scientists have predicted it could take over 5 percent of the continent. It’s a grass cane toad, if you like.
IT: So it was introduced to feed a herbivore and become rampant, so requires a mega-herbivore to control it?
DB: My suggestion is deliberately provocative. It’s an elephant of a grass from Africa; maybe the only way to control it is with an African animal. The orthodoxies such as spraying herbicide don’t work effectively.
IT: Although there are well-documented cases where introducing an alien species has been a disaster, you say there have been successes?
DB: The control of the prickly pear with a moth is a textbook example. There is also a very good example that isn’t well known. In the early 19th century, the British wanted to establish another trading port in northern Australia, so they set up Port Essington. The idea failed and the inhabitants died or abandoned it. One of the animals they left behind was a cattle species. The Aborigines knew about it, but science didn’t know about it until it got rediscovered in 1961. Genetic analysis discovered that this thing is banteng — a highly endangered wild Southeast Asian cattle species. So Australia now has the largest population of it by accident. The punchline is that the Aboriginals [sic] value it, safari hunters hunt it and it doesn’t appear to have any environmental detriment to the national parks where it resides — it may even be quite good, a lot of small mammals have done quite well.
IT: And camels and water buffalo have flourished in Australia ...