February 1, 2012 | 10
Why not bring elephants to Australia? That’s the proposal made by biologist David Bowman of the University of Tasmania in a comment published February 2 in Nature. (Scientific American is part of Nature Publishing Group.)
The pachyderms could help to polish off gamba grass, introduced from Africa to Australia in the 1930s as fodder for cattle. Nowadays, it also provides fuel for devastating fires, such the one that killed 173 people and burned 400,000 hectares on February 7, 2009. Neither local cattle nor kangaroos consume enough of the weedy grass to keep it in check.
But African savannah elephants eat plenty of it, so why not import them to control the fire fodder? The approach also could start to remedy 50,000 years worth of human impacts—from the hunting of ancient giant marsupials to the introduction of alien species such as gamba grass. It’s an attempt to begin to restabilize food webs that have been “out of balance,” according to Bowman, for tens of thousands of years.
In fact, no continent has a worse record of human ecological devastation, some of it even well-intentioned. Australia is a hotbed of introduced species: a whole suite of European mammals runs wild there, from buffalo to rabbits. Even camels have gone feral after being imported in the 19th century for transportation. Perhaps most famously, the cane toad was introduced to control an agricultural pest but found the antipodes to its liking and is now frog-marching through the outback with devastating effects on indigenous marsupials.
So, Bowman’s plan is well-intentioned: imported African elephants or other “uber-herbivores,” such as critically endangered rhinos, could help to control the gamba grass. But unlike other “re-wilding” schemes around the globe, no member of the modern day elephant family has ever lived in Australia in the wild, though giant marsupials of the past may have played a similar role in that ancient ecosystem now long gone. And elephants can become pests—witness South Africa’s practice of culling herds to protect native flora. “The greatest challenge would be managing the density of herbivore populations so that their demand on resources does not degrade the ecosystem,” Bowman wrote. Indeed, and there is nothing to say that introduced elephants might not chomp on embattled native plants along with gamba grass.
Bowman also suggests importing the Komodo dragon from Indonesia to fill the predatory role once played in Australia by ancient giant lizards or, perhaps least controversially, stopping the poisoning of a predator that still exists—the dingo. Letting dingoes rebound could act as a check on the spread of other feral mammals. Of course, that would aid and abet an ecological process kicked off by the ancestors of Aborigines when they brought the wild dogs to the continent tens of thousands of years ago. It seems that humans have been messing with the ecology down under for a very long time and show little inclination to stop.