One of the many difficulties faced by the pioneers of Australia’s sheep industry was finding a reliable shepherd. Among the convict labour available, for every two experienced farm labourers there were five convicted sheep, horse, cattle or poultry thieves.
The conditions were demanding. Convicts returning from pasture with fewer sheep than they left with faced a penalty of up to 100 lashes – close to a death sentence. Going bush was the only option for those unwilling to submit to the punishment back “inside”, as the settlements were called. Sheep were lost through negligence and misadventure, others to hungry dingoes.
Eradicating dingoes therefore had a double benefit for the graziers: they would reduce stock losses, and eliminate the need for (unreliable) convict labour.
Reverend Samuel Marsden announced the first plan for the destruction of the native dog in Sydney Town, 1811. On offer was a generous bounty of one gallon of spirits for each complete skin of a fully grown native dog.
(Incidentally, Marsden went on to introduce sheep to New Zealand, followed by the mysterious disappearance of the Maori kuri dog in following decades.)
Three years later, the first instance of using poison to eradicate the dingo was recorded in the Sydney Gazette. A “gentleman farmer” with extensive stock in the Nepean District initiated the operation. By applying arsenic to the body of a dead ox on his property, he managed to eradicate all the wild dogs from his landholding. The technique gathered a quiet following, though there were concerns that in the wrong hands this venture could inadvertently backfire on the penal colony.
In 1818 French scientist Pierre Joseph Pelletier successfully extracted beautiful but sinister crystals from the plant nux vomica. This discovery revolutionised toxicology: it enabled mass production of a highly toxic, stable and cheap poison known as strychnine.
The crystals were soon to be exported en masse around the world. Strychinine became an essential item in the Australian farmer’s toolkit, and by 1852 its use on landholdings was mandatory to control unwanted wildlife. In 1871 author Anthony Trollope wrote in his observations of Australian life:
On many large runs, carts are continually being taken round with (strychnine) baits to be set on the paths of the dingo. In smaller establishments the squatter or his head-man goes about with strychnine in his pocket and lumps of meat tied up in a handkerchief.
Over the course of the 19th century, the Australian economy became irreversibly dependent on this industrial agrochemical farming system.
The pace of Australia’s agricultural revolution was rapid; between 1822, when fine wool became NSW’s major export product, and 1850, the national flock numbers increased from 120,000 to 16 million. By 1892 the Australian sheep flock numbered 106 million.
A central Australian dingo extermination campaign was launched in 1897, to eradicate dingo and rabbit populations from South Australia’s arid zone. Described as the “Party of Poisoners”, the team travelled from Gawler Range to Wilpena Pound, covering an area 1,000km long by 480km wide. It took five months.
The poisoners dispensed phosphorised pollard and strychnine sticks and laid poisoned grain in lightly covered furrows. Meat baits were placed around the bases of the red and white mallee bush. Billabongs were poisoned. All species that might have competed for the scarce resources were effectively eliminated – carnivore and herbivore. Farming ultimately failed in the region. The natural biodiversity never recovered.
The legacy of Australia’s chemical-dependent farming over the past 200 years remains largely unacknowledged in conversations about the current biodiversity crisis. Australia has around 500 threatened animal species, and our rate of mammalian extinctions is unparalleled anywhere in the world. The main drivers of the crisis are attributed to introduced species, changed fire regimes, and land clearing.
In the history of agricultural expansion, it was the dingo that was the initial target of eradication campaigns. Land clearing worked in concert with the broad scale application of vertebrate pesticides. The expansion in the application, range, methods of delivery and quantity of poison and poisoned baits applied was rapid, using increasingly sophisticated machinery.
The effects reverberated throughout Australia’s ecosystems: the removal of the dingo, the top order predator, lead to the explosion of herbivore populations, more poisons, the establishment of introduced species and destabilising of the native ecosystem.
In the 1870s newspapers were reporting on the impact of herbivore populations including the introduced rabbit. The South Australian Advertiser, wrote in 1877:
We have destroyed the balance of nature in two ways simultaneously, by destroying the carnivore and introducing a new herbivorous animal of immense reproductive powers.
In the 21st century, more vertebrate poisons are dispensed by air in National Parks, than on private land – in efforts to protect biodiversity from invasive species.
My research examines how poison has been normalised in land management. The use of vertebrate pesticides has been supported by services and systems embedded within Australia’s social, political and legal framework for 200 years.
Applying more vertebrate pesticides to the environment to try and solve the problem, is arguably an extreme case of mistaking the poison for the cure.
Giant eucalypts play an irreplaceable part in many of Australia’s ecosystems. These towering elders develop hollows, which make them nature’s high-rises, housing everything from endangered squirrel-gliders to lace monitors. Over 300 species of vertebrates in Australia depend on hollows in large old trees.
These “skyscraper trees” can take more than 190 years to grow big enough to play this nesting and denning role, yet developers are cutting them down at an astounding speed. In other places, such as Victoria’s Central Highlands Mountain Ash forests, the history of logging and fire mean that less than 1.2% of the original old-growth forest remains (that supports the highest density of large old hollow trees). And it’s not much better in other parts of our country.
David Lindenmayer explains how these trees form, the role they play – and how very hard they are to replace.
Have you ever got on a flight and the person next to you started sneezing? With 37 million scheduled flights transporting people around the world each year, you might think that the viruses and other germs carried by travellers would be getting a free ride to new pastures, infecting people as they go.
Yet pathogenic microbes are surprisingly bad at expanding their range by hitching rides on planes. Microbes find it difficult to thrive when taken out of their ecological comfort zone; Bali might just be a tad too hot for a Tasmanian parasite to handle.
But humans aren’t the only species to go global with their parasites. Billions of animals have been flying, swimming and running around the globe every year on their seasonal migrations, long before the age of the aeroplane. The question is, are they picking up new pathogens on their journeys? And if they are, are they transporting them across the world?
Migratory animals are the usual suspects for disease spread
With the rate of zoonotic diseases (pathogens that jump from animals to humans) on the rise, migratory animals have been under increasing suspicion of aiding the spread of devastating diseases such as bird flu, Lyme disease, and even Ebola.
These suspicions are bad for migrating animals, because they are often killed in large numbers when considered a disease threat. They are also bad for humans, because blaming animals may obscure other important factors in disease spread, such as animal trade. So what’s going on?
Despite the logical link between animal migration and the spread of their pathogens, there is in fact surprisingly little direct evidence that migrants frequently spread pathogens long distances.
This is because migratory animals are notoriously hard for scientists to track. Their movements make them difficult to test for infections over the vast areas that they occupy.
But other theories exist that explain the lack of direct evidence for migrants spreading pathogens. One is that, unlike humans who just have to jump on a plane, migratory animals must work exceptionally hard to travel. Flying from Australia to Siberia is no easy feat for a tiny migratory bird, nor is swimming between the poles for giant whales. Human athletes are less likely to finish a race if battling infections, and likewise, migrant animals may have to be at the peak of health if they are to survive such gruelling journeys. Sick travellers may succumb to infection before they, or their parasitic hitchhikers, reach their final destination.
Put simply, if a sick animal can’t migrate, then neither can its parasites.
On the other hand, migrants have been doing this for millennia. It is possible they have adapted to such challenges, keeping pace in the evolutionary arms race against pathogens and able to migrate even while infected. In this case, pathogens may be more successful at spreading around the world on the backs of their hosts. But which theory does the evidence support?
Sick animals can still spread disease
To try and get to the bottom of this question, we identified as many studies testing this hypothesis as we could, extracted their data, and combined them to look for any overarching patterns.
We found that infected migrants across species definitely felt the cost of being sick: they tended to be in poorer condition, didn’t travel as far, migrated later, and had lower chances of survival. However, infection affected these traits differently. Movement was hit hardest by infection, but survival was only weakly impacted. Infected migrants may not die as they migrate, but perhaps they restrict long-distance movements to save energy.
So pathogens seem to pose some costs on their migratory hosts, which would reduce the chances of migrants spreading pathogens, but perhaps not enough of a cost to eliminate the risk completely.
But an important piece of the puzzle is still missing. In humans, travelling increases our risk of getting ill because we come into contact with new germs that our immune system has never encountered before. Are migrants also more susceptible to unfamiliar microbes as they travel to new locations, or have they adapted to this as well?
Guts of migrants resistant to microbial invasion
To investigate the susceptibility of migrants, we went in a different direction and decided to look at the gut bacteria of migratory shorebirds – grey, unassuming birds that forage on beaches or near water, and that undergo some of the longest and fastest migrations in the animal kingdom.
Most animals have hundreds of bacterial species living in their guts, which help break down nutrients and fight off potential pathogens. Every new microbe you ingest can only colonise your gut if the environmental conditions are to its liking, and competition with current residents isn’t too high. In some cases, it may thrive so much it becomes an infection.
We found the migratory shorebirds we studied were exceptionally good at resisting invasion from ingested microbes, even after flying thousands of kilometres and putting their gut under extreme physiological strain. Birds that had just returned from migration (during which they stopped in many places in China, Japan, and South East Asia), didn’t carry any more species of bacteria than those that had stayed around the same location for a year.
Although these results need to be tested in other migratory species, our research suggests that, like human air traffic, pathogens might not get such an easy ride on their migratory hosts as we might assume. There is no doubt that migrants are involved in pathogen dispersal to some degree, but there is increasing evidence that we shouldn’t jump the gun when it comes to blaming migrants.
Alice Risely, PhD candidate in Ecology, Deakin University; Bethany J Hoye, Lecturer in Animal Ecology, University of Wollongong, and Marcel Klaassen, Alfred Deakin Professor and Chair in Ecology, Deakin University
Throughout history, humans have taken plants and animals with them as they travelled the world. Those that survived the journey to establish populations in the diaspora have found new opportunities as they integrate into new ecosystems.
These immigrant populations have come to be regarded as “invaders” and “aliens” that threaten pristine nature. But for many species, migration may just be a way to survive the global extinction crisis.
In our recently published study, we found that one of the Earth’s most imperilled group of species is hanging on in part thanks to introduced populations.
Megafauna – plant-eating terrestrial mammals weighing more than 100kg – have established in new and unexpected places. These “feral” populations are rewilding the world with unique and fascinating ecological functions that had been lost for thousands of years.
In New Zealand, a mere 800 years ago, a riot of giant flightless birds still grazed and browsed the landscape.
The loss of Earth’s largest terrestrial animals at the end of the Pleistocene was most likely caused by humans.
Sadly, even those large beasts that survived that collapse are now being lost, with 60% of today’s megafauna threatened with extinction. This threat is leading to international calls for urgent intervention to save the last of Earth’s giants.
A wilder world than we think
Formal conservation distribution maps show that much of Earth is empty of megafauna. But this is only a part of the picture.
Many megafauna are now found outside their historic native ranges. In fact, thanks to introduced populations, regional megafauna species richness is substantially higher today than at any other time during the past 10,000 years.
Worldwide introductions have increased the number of megafauna by 11% in Africa and Asia, by 33% in Europe, by 57% in North America, by 62% in South America, and by 100% in Australia.
Australia lost all of its native megafauna tens of thousands of years ago, but today has eight introduced megafauna species, including the world’s only wild population of dromedary camels.
These immigrant megafauna have found critical sanctuary. Overall, 64% of introduced megafauna species are either threatened, extinct, or declining in their native ranges.
Some megafauna have survived thanks to domestication and subsequent “feralisation”, forming a bridge between the wild pre-agricultural landscapes of the early Holocene almost 10,000 years ago, to the wild post-industrial ecosystems of the Anthropocene today.
Wild cattle, for example, are descendants of the extinct aurochs. Meanwhile, the wild camels of Australia have brought back a species extinct in the wild for thousands of years. Likewise, the vast majority of the world’s wild horses and wild donkeys are feral.
There have been global calls to rewild the world, but rewilding has already been happening, often with little intention and in unexpected ways.
A small population of wild hippopotamuses has recently established in South America. The nicknamed “cocaine hippos” are the offspring of animals who escaped the abandoned hacienda of Colombian drug lord Pablo Escobar.
By insisting that only idealised pre-human ecosystems are worth conserving, we overlook the fact that these emerging new forms of wilderness are not only common but critical to the survival of many existing ecosystems.
Megafauna are Earth’s tree-breakers, wood-eaters, hole-diggers, trailblazers, wallowers, nutrient-movers, and seed-carriers. By consuming coarse, fibrous plant matter they drive nutrient cycles that enrich soils, restructure plant communities, and help other species to survive.
The wide wanderings of megafauna move nutrients uphill that would otherwise wash downstream and into the oceans. These animals can be thought of as “nutrient pumps” that help maintain soil fertility. Megafauna also sustain communities of scavengers and predators.
In North America, we have found that introduced wild donkeys, locally known as “burros”, dig wells more than a metre deep to reach groundwater. At least 31 species use these wells, and in certain conditions they become nurseries for germinating trees.
The removal of donkeys and other introduced megafauna to protect desert springs in North America and Australia seems to have led to an exuberant growth of wetland vegetation that constricted open water habitat, dried some springs, and ultimately resulted in the extinction of native fish. Ironically, land managers now simulate megafauna by manually removing vegetation.
It is likely that introduced megafauna are doing much more that remains unknown because we have yet to accept these organisms as having ecological value.
Living in a feral world
Like any other species, the presence of megafauna benefits some species while challenging others. Introduced megafauna can put huge pressure on plant communities, but this is also true of native megafauna.
Whether we consider the ecological roles of introduced species like burros and brumbies as desirable or not depends primarily on our own values. But one thing is certain: no species operates in isolation.
Although megafauna are very large, predators can have significant influence on them. In Australia, dingo packs act cooperatively to hunt wild donkeys, wild horses, wild water buffalo and wild boar. In North America, mountain lions have been shown to limit populations of wild horses in some areas of Nevada.
Visions of protected dingoes hunting introduced donkeys and Sambar deer in Australia, or protected wolves hunting introduced Oryx and horses in the American West, can give us a new perspective on conserving both native and introduced species.
Nature doesn’t stand still. Dispensing with visions of historic wilderness, and the associated brutal measures usually applied to enforce those ideals, and focusing on the wilderness that exists is both pragmatic and optimistic.
After all, in this age of mass extinction, are not all species worth conserving?
This research will be presented at the 2017 International Compassionate Conservation Conference in Sydney.
Erick Lundgren, PhD Student, Centre for Compassionate Conservation, University of Technology Sydney; Arian Wallach, Chancellor’s Postdoctoral Research Fellow, Centre for Compassionate Conservation, University of Technology Sydney; Daniel Ramp, Associate Professor and Director, Centre for Compassionate Conservation, University of Technology Sydney, and William Ripple, Distinguished Professor and Director, Trophic Cascades Program, Oregon State University
The Earth is home to millions of species, but you wouldn’t know it from the media’s obsession with only a few dozen animals like tigers and gorillas.
This narrow focus makes the most of popular fascination with large and cute creatures. Conservationists take advantage of these nonhuman celebrities to raise awareness about important issues and to seek donations to help save endangered animals. Given the multi-billion-dollar funding shortfall for nature conservation, public support is crucial.
Very popular species attract the most wildlife conservation funding. But what about the Nimba otter shrew, the Cuban greater funnel-eared bat or other threatened yet obscure species? And don’t all imperiled green spaces, not just the homes of snow leopards and orangutans, deserve attention?
Conventional wisdom counsels sticking with the old approach to fundraising, and conservationists tend to see animals like bats and snakes as lost causes. As conservation scientists, we wanted to discover whether marketing could perhaps rescue these species. If companies can successfully sell mops and other humdrum products, why can’t conservationists raise money to save the unglamorous giant golden mole – even if it looks like a small cushion with a nose poking out of it? We sought the answer to this question by measuring the links between marketing efforts and conservation fundraising success.
Two different animals
Our recently published study contrasted online fundraising campaigns by two conservation charities: World Wildlife Fund-US (WWF-US) and the Zoological Society of London (ZSL), through its EDGE of Existence program.
These campaigns are very different. WWF-US raises money for a broad set of projects, addressing global issues from climate change and illegal wildlife trade to forest and ocean conservation. The EDGE campaign we analyzed focuses on saving 100 threatened mammal species.
Given these contrasting approaches, we wanted to see if and when marketing makes a difference. To do this we also had to account for whether the species used for fundraising mattered. This involved measuring an animal’s “appeal,” which depends on lots of factors, such as whether it is cute, large or famous. To see which animals were the most appealing, we showed 850 conservation supporters a random selection of the animal photos featured on the WWF-US and EDGE websites and asked these volunteers to rank the photos.
Let’s first consider WWF-US, which raises money through animal “adoptions.” When people donate, they signal their support for the well-known species. In return they get a stuffed toy, photos of the animals and adoption certificates. But the money WWF-US raised funds projects that benefit more than just the “adopted” animals.
We found two factors influenced WWF-US donors’ choices: the animals’ appeal and the degree of the threat of their extinction. Marketing efforts played no role. No matter how they were described or presented, the most appealing species always drew more donations. This was probably because people already knew and liked them.
The EDGE program raises money in a different way. It supports some universally familiar animals, like the Asian elephant, but many of the species it helps are less appealing to humans, including a variety of rats and bats. Each of these species is shown on their website, so people can click on a link to find out more and then donate.
We found that while people were generally more interested in donating to appealing species, the amount of marketing also made a difference. The animals EDGE actively promoted fared better with potential donors – including some homely ones. Similarly, pitches for the species shown higher up on EDGE’s site got more donors interested in funding the animals’ conservation.
A way to save the rodents
EDGE’s track record suggests that using marketing techniques to raise money for wildlife conservation could increase donations aimed at helping less popular species. To estimate the difference that marketing could make in this regard, we created a mathematical model based on our analysis of the EDGE data. This is an equation that predicts donations based on a species’ appeal (which is fixed) and whether it was promoted by EDGE or shown high up on the website (which we could vary).
Partnering with an EDGE staff member, we then modeled different fundraising scenarios for the 10 most appealing and 10 least appealing animals, as rated by our conservation volunteers. With no marketing effort, our model predicted that the most appealing species would raise 10 times more money than the least appealing animals. This was in line with what we expected and supported the WWF-US strategy.
However, things changed when we modeled the impact from EDGE’s marketing efforts. If the group highlighted the least appealing species by making them prominent on its website, our model predicted a 26-fold increase in donations for those specific animals. This suggests that charities could raise conservation funds for species like bats and rodents, if they tried hard enough.
Our findings indicate that conservationists have more options than they may realize to raise money to aid wildlife.
When can marketing boost donations?
But when should they fundraise for more obscure species? The answer depends on how threatened the animal is, how much help it already gets, the cost of saving it and the chances of the project succeeding. When conservationists focus only on saving elephants, rhinos or other popular species, they often overlook these considerations.
That doesn’t mean WWF-US should end its focus on familiar animals. Since the money it raises funds broad projects that benefit more than just the “adopted” animals, catering to widespread fixations with particular species makes sense.
To be sure, our research did not measure whether marketing efforts pay off by increasing donations overall. But including more kinds of species in a campaign may boost donations – especially for endangered frogs and tarantulas or other underappreciated animals – and even plants.
It might also increase the total number of species in the public eye, highlighting the many ways everyone can help save wildlife.
Conservationists often complain animals that are important to save can get ignored. Our results suggest that they should stop complaining and start marketing.
The graphic containing endangered animals in this article that was originally published on June 21, 2017 was corrected on July 5, 2017. The new version contains the top five animals for EDGE’s fundraising. The old version misidentified and featured the other five in the group’s top 10.