David Bowman, University of Tasmania
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Sarah - Since humans first set foot in Australia, 50,000 years ago, we've pretty much spelled disaster for the continent. The first settlers wiped out the continent’s megafauna, including species of giant kangaroo, and the early English colonists introduced foxes, cats, camels, rodents, rabbits, and even poisonous cane toads, and rampant African grasses – all of which had a devastating effect on the ecology of the country and have driven many of the native species to extinction. So, when an Australian Professor of ecology published a paper suggesting that the answer might actually be to accept that we’re never going to return Australia to how it once was and to introduce even more non-native species including elephants to at least stabilise the status quo, it was bound to be controversial. Chris Smith spoke to the author of that paper, the University of Tasmania’s David Bowman...
David - I've recently published a paper in Nature which is a very controversial opinion piece about the environmental management challenges in Australia associated with uncontrolled fires, feral animals, and how they've interacted with the unusual biogeography of the Australian continent. We’ve sort of started a cake mix - we’re mixing up all of these ingredients, now do we try to actually make this cake rise and work as a cake or do we just leave it as some sort of weird slurry? Because all of the introductions which have been made and the changes to fire regimes have all been effectively accidental. So, we already have a very mixed up ecology and the possibility of returning our ecology to anything like Captain Cook would have seen is an impossible dream given the record extinction rates which have occurred in Australia.
We’re in a real predicament and I think that the lesson is that humans have to manage nature, we’re in the Anthropocene. We can't just assume that natural systems are going to be self-righting if we’ve really hammered the natural systems with quite dramatic stresses and introductions. It’s very controversial thinking, but I've been living with these problems for 30 years and it was about time somebody said something.
Chris - So what you would argue is that in the past, these introductions and these things have been either mistakes or ill-conceived. But actually, if we use our brains now and start making changes which are based on science and clear evidence, then we could actually work with the problem we’ve got to help to resolve it and arrive at a better outcome than if we just let things go and try and conserve the status quo, because the status quo is an unstable one.
David - I think that's the key point. We’ve moved on and obviously as ecologists, we have much greater understanding of the need for stabilising food webs and the impact of trophic cascades - when you disrupt food chains and how that can actually result in dramatic landscape scale changes. All of this thinking is really ripe to trialling things because what we should be striving to do in Australia is forget about the extermination paradigm and "return Australia to its 1788 Captain Cook status", and more to manage impacts and reduce the impacts of these "threatening processes". Through that, with that human engagement and possibly using some animals as ecological machines to achieve certain outcomes, we can basically steer or stabilise our systems way better than if we just let nature take its course.
Chris - How has this gone down with the Australian public? If you talk to people in Australia, they have been very heavily educated about the impact that introductions and feral animals have had on Australian ecology and for an Australian ecologist to then turn around and say, “We need actually to do this more,” they must have quite a strong reaction to that, don't they?
David - Yeah, it’s very interesting. Amongst my colleagues, I've been very pleasantly and warmly surprised by the “elephants, a crazy idea but wow! Isn't it great?” response. The people are putting all of the options on the table and stiring up this debate, so a lot of support. Amongst the media, it’s a little bit polarised between people just treating it as an absurd joke, who laugh or others who say "yeah, that's a big idea - how do we control some things which are uncontrolled if our plan A approaches aren’t working?" Because we’re about to run into these problems and I think that the way to advance this is that you have lots of debates and some trials so we can start being a lot more adaptive. We haven’t even talked about climate change which is another layer on top of this horrible complex mess we’re in.
Chris - So how would you do this in a safe way so we don't see the cane toad problem all over again?
David - Right. Well one thing which is really important to bear in mind is that there's a global dimension. I got a fascinating email from a game manager in Namibia pointing out that when you project at the hundred to a thousand-year perspective on Africa, it’s very difficult to see a future for a lot of animals. Just the sheer environmental changes driven by people pressure. Here, we’ve got a low population density in Australia, we could have game parks. A lot of Australians think that's repugnant, but a cattle farm is okay. But how would we do it? Of course, we’d have to trial things and we’d have to invest money. I would like to see somebody work through the calculation of saying, “Well let’s look at all of the available options and a few crazy options to control this out-of-control grass. Let’s look at it all and let’s cost them with the knowledge we’ve got available and start a genuine engagement". At the moment, all that's happening is that people are saying, “This is a very bad weed” but in a holistic sense, nobody is doing anything. I would call that an out of control situation and you know, I'm certain that there are solutions to stabilise this, but I'm not quite certain how to do it.
Conservation: Bring elephants to Australia? David Bowman; Nature; 482, 30 (02 February 2012) doi:10.1038/482030a