By Tim Smith
27th April 2014
Many of the world’s largest carnivores are under threat from hunting, habitat loss and climate change, according to a recent paper by ecologist William Ripple and his colleagues from North America, Europe and Australia. Their list of endangered species includes lions, leopards, panthers, tigers, sea otters, polar bears… and dingoes.
This should come as no surprise to most of us, as we are now accustomed to hearing extinction messages about iconic species from conservation groups and wildlife campaigners. However, the consequences of these losses to humans have been less well documented by the media, at least until recently.
Observation of the effects of declining numbers of these top predators has led to the recognition that these species play a pivotal role in maintaining the health of the ecosystems that they inhabit. Their loss results in the proliferation of their prey and other, smaller predators in the region, which in turn causes a cascade of effects throughout the ecosystem, resulting in changes to vegetation, birds, mammals, reptiles and waterways. The overall effect is landscape degradation, which means a loss of vital ecosystem services and biodiversity.
In my previous blog I discussed rewilding, a conservation approach which attempts to restore ecosystems by reintroducing these apex predators, thus allowing other native species of flora and fauna to regenerate naturally.
But does rewilding have any application in Australia?
The term rewilding probably has less resonance in Australia than it does in highly urbanised and industrialised regions such as Europe. Australia still retains a wild image, with its vast uninhabited spaces and iconic species, which have generated an important eco-tourism industry.
However, this image hides the reality that over the past 150 years, Australia has experienced the highest rate of mammal decline and extinction on earth, with eighteen species lost since European settlement. This is thought to be due to the proliferation of introduced animals such as the fox and feral cat. In addition to this, other non-native species such as feral pigs, goats, camels, deer, buffalo and rabbits have wreaked further havoc upon Australia’s ecosystems.
The dingo dilemma
Since the extinction of the Tasmanian tiger in 1936, the only remaining mammalian top predator in Australia is the dingo (itself an introduced species, arriving about 4000 years ago from Southeast Asia). However, the dingo, like the wolf and many other predators throughout the world, was seen by European setters as undesirable due to its propensity to prey on livestock.
Consequently there have been widespread attempts to curb its numbers by methods such as shooting and poisoning, culminating in the establishment in 1946, of a 5400km dingo proof fence, running from the Great Australian Bight across South Australia, through New South Wales, and ending at the Bunya Mountains in Queensland.
While the fence may have been effective in protecting the sheep industry, keeping dingoes out of these areas has led to environmental problems, as is predicted by the trophic cascade theory described above.
Studies by Letnic and colleagues either side of the fence, observing ecosystems with and without dingoes, have demonstrated that they do indeed appear to exert beneficial regulatory effects on ecosystems, just like their counterparts in other regions.
Where dingoes are present, there are greater numbers of small native animals, such as bilbies and rock-wallabies, which is thought to be due to control of red fox and feral cat numbers. They also control the numbers of herbivores, such as kangaroos and rabbits, thus preventing overgrazing and nutrient depletion from soil.
Conversely, their absence may have contributed to the extinction of small marsupials, erosion of vegetation, and excessive herbivore numbers, which then compete for precious grazing land with livestock.
It should be noted however, that not all scientists accept the importance of the dingo in regulating ecosystems, possibly because much of the initial research has come from arid regions of Australia, with less research from forested and coastal areas, although this is now accumulating. Nevertheless, given the abundance of literature worldwide that supports the role of apex predators (such as the dingo) in shaping ecosystems, it is argued that the burden of proof should now be on showing that they do not exert these trophic effects.
So, befitting the rewilding ethos, it has been suggested by a number of ecologists that we should reconsider the culling of dingoes and allow them to resume their role as a top predator, naturally controlling feral species and thus protecting native marsupials and vegetation, with the caveat that non-lethal measures of dingo control could be employed to protect livestock.
It should also be said that rewilding does not necessarily have to involve the reintroduction of apex predators, although this obviously attracts greater media attention. It simply means allowing or assisting degraded ecosystems to regenerate naturally, and while in some cases this may require a large carnivore, in others, it may involve the less glamorous work of planting and protecting native vegetation.
An inspirational example of this is Gondwana Link, a collaborative project in south-western Australia. This region is a globally important biodiversity hotspot, but it is being threatened by extensive agricultural clearing. The project is ambitious, and aims to link a 1000km long strip of fragmented native bushland, running from the southwest corner of WA to the Nullabor plain, restoring ecological connectivity.
So, in Australia, as in other parts of the world, the ecological argument for rewilding is generally sound, and is now backed by some empirical evidence, but in reality the thorny issue of human-predator conflict must be addressed; this is the real crux of the problem of getting rewilding with predators to work.
If we are to conserve biodiversity, we must learn to co-exist with large carnivores such as the dingo. A number of solutions have been used in other parts of the world to help facilitate this coexistence: financial reimbursement for farmers whose sheep or cattle are killed, use of guard dogs and barrier fencing to protect livestock, and the economic incentives of eco-tourism, hunting and wild meats (where appropriate). However, many would argue that the most important solution is a change in human attitudes and behaviour towards the natural world.
But why should humans care about such abstract concepts as ecosystem services and conservation of biodiversity? Why should we care about the fate of dingoes and bilbies to the extent that these become priorities that trump other more immediate concerns in our daily lives?
Psychological studies have demonstrated that some people are biocentrics: they care about nature regardless of its usefulness to our quality of life; they believe it has intrinsic value. Sadly for nature however, the majority of humans believe that the non-human world only has value when it provides a useful service to us. This is not to say that they are not moved by campaigns that highlight the plight of polar bears or pandas, but research has shown that negative messages about extinction tend to provoke a sense of apathy and powerlessness, rather than motivating people to change their behaviour.
This is not necessarily bad news, as recognising this reality allows communicators and conservationists to develop more effective, pragmatic messages aimed at this non-biocentric audience.
According to the sustainability communications agency, Futerra, conservationists must start branding biodiversity. This means dropping the paralyzing, negative, extinction-based campaigns, and adopting a new strategy that uses a positive message to reawaken our innate love, awe and fascination for the natural world, coupled with practical information about what we can do to help. Indeed, one of the justifications for rewilding is that it may help to do exactly this.
Advertising agencies and politicians know that there are a number of ways of getting your message across to a target audience, one of which is to use “frames” or storylines that resonate with their existing values and attitudes. This might mean using arguments based on economics, ethics/ religion or national security.
An effective approach for promoting biodiversity conservation that is gaining traction is to focus on the benefits to human health. Using this frame, the majority of people, the non-biocentrics, might be convinced to love and care for nature (including dingoes!) for all the ecological benefits provided to us, free of charge, that are absolutely essential for our health and well-being.
So why does our health depend on intact ecosystems and biodiversity?
Biodiversity (which means not only variety in species of plant and animal, but also microorganisms, genes and ecosystems) is essential as a source of food, healthy crops, medicines (eg. aspirin, warfarin, antibiotics, chemotherapeutic agents), and for the regulation of infectious diseases (eg. malaria).
As demonstrated by scientists such as Ripple and Letnic, biodiversity is also a prerequisite for healthy ecosystems, which provide us with fresh water, healthy soil, timber, fibre, fuel, carbon sequestration, flood mitigation, recreation, spiritual nourishment and education.
Without these things, in the short-term our health will suffer, and in the long-term we will not survive. Isn’t it time we all started to think this way?