Who's afraid of the big bad wolf: Is the dingo friend or foe?September 5th, 2013 in Biology / Ecology
Is removing a top predator really an experiment we want to try? Credit: AAP
Another attack on Fraser Island – the flashpoint for dingo management issues – has highlighted our complex relationship with these animals once again.
But when we shoot and trap dingos, do we really know what we're doing?
A predator's plight
Along with koalas and kangaroos, the dingo is one of Australia's most recognisable and iconic species, and yet it suffers from an identity crisis that threatens its continued survival in the wild.
As a top predator, the dingo is not alone in being threatened with extinction.
Across the globe, species such as wolves, bears, mountain lions and tigers are walking a knife's edge between survival and extinction.
Shark populations, the top predators of our oceans, have been reduced by more than 90%.
As a result they are intensively controlled through poisoning, shooting and trapping.
But others consider dingoes to be our best chance at saving many of our native threatened and endangered species from extinction.
These people argue for the continued preservation of dingoes and, most controversially, that dingoes need to be reintroduced into some areas.
Learning from the wolves
If this story sounds familiar to you, that is because it is almost identical to the history of wolf conservation in North America, and the controversy that surrounded their famous reintroduction into Yellowstone National Park in 1995-96, after a near 90-year absence.
The reintroduction of wolves led to a noticeable reduction in grazing by previously overabundant elk, and subsequent significant recovery of native aspen, willow and cottonwood trees.
Indeed, the wolves' positive effects were felt throughout the entire ecosystem.
The reintroduction of wolves led to beavers returning, increases in numbers of some small predators and scavengers, but equally importantly, reductions in coyotes, which indirectly benefited the threatened pronghorn antelope population.
Dingoes and invasive species: Alien vs Predator
So what relevance does this story hold for Australia?
Recent research from around the globe is demonstrating that large predators, including dingoes, play a critical role in maintaining the health of our ecosystems.
Predators make ecosystems more resistant to the negative impacts of invasive species and climate change.
The most critical effects dingoes have on the Australian landscape are in reducing populations of both overabundant herbivores (such as kangaroos) and introduced smaller-bodied predators, specifically cats and foxes.
Many thousands of dollars are spent annually in attempting to control overabundant kangaroo populations because of their perceived impacts on livestock grazing.
Unchecked kangaroo numbers can undoubtedly devastate habitats, in some cases leading to near complete removal of vegetation and severe erosion.
These effects, combined with those of cats and foxes, which prey heavily on small to medium-sized native animals, place huge pressure on our native biodiversity.
Encouragingly, large-scale, ecological studies from across Australia are now showing unequivocally that dingoes, where left alone and in reasonable numbers, are able to reduce cat, fox and kangaroo numbers substantially.
Running counter to this is the unfortunate media attention surrounding dingoes, including attacks like the one on Fraser Island this Easter, and stock losses attributed to dingoes or wild dogs.
Such events do not aid the case to restore dingoes across Australia as a matter of urgency.
Conserve or cull?
The dingo has recently been identified as a threatened species by the Victorian government (in part due to the risk of hybridisation with feral domestic "wild" dogs.)
But at the same time, this government is also contemplating aerial poison baiting to control wild dog populations. Such decisions would appear at odds with each other.
Regardless of political challenges, the question arises: if we accept the value of dingoes and abandon our attempts to eradicate them, how can we manage the risk they pose to the economic viability of livestock grazing?
The answer to that question is not simple and requires us to take a broad view of land management than we do at present.
Dingoes not dollars
It's certainly true that dingoes on occasion kill and eat livestock, but at the same time they also kill millions of kangaroos, pigs, feral goats and rabbits annually.
This effect indirectly benefits sheep and cattle by reducing competition for food, and ultimately benefits graziers' hip pockets.
Importantly, the services provided by dingoes come for free, as opposed to our own costly pest control and conservation interventions.
We need to assess in dollars and cents how much stock loss we may incur by maintaining dingoes in the landscape against the positive effects dingoes have in controlling cats, foxes and herbivores, and how this assists conserving our native species.
In some situations we may even be able to have our cake and eat it too.
We can protect stock that may be vulnerable to dingo attack using livestock guardian animals (such as Maremma dogs), and still maintain dingoes in the landscape to control the unwanted impacts of cats, foxes and overabundant herbivores.
What a coup that would be.
Provided by The Conversation
This story is published courtesy of The Conversation (under Creative Commons-Attribution/No derivatives).
"Who's afraid of the big bad wolf: Is the dingo friend or foe?." September 5th, 2013. http://phys.org/news/2013-09-afraid-big-bad-wolf-dingo.html