Nature in Australia is a mess. There’s no need to go into details. You’ve seen it: the thousands of dead fish in drying rivers, three billion animals killed or displaced by bushfire, environmental legislation that privileges developers over endangered species. Up against all this are conservationists—scientists and activists slogging away in a losing battle to explain the size of the problem, to get laws changed, to stop a tree being felled or a mine being opened, to pluck species from the brink of destruction with monitoring and intervention.
For most of Australia’s conservation history, those fighting on the side of nature—from ecologists to birdwatchers to tree-sitters and warm-hearted animal lovers—have cleaved to the belief that native species are good and introduced species are bad, that getting rid of introduced species will go a long way to solving nature’s worst problems. As a child of environmentalists, I was fed this belief with my Vegemite on toast. But as natural systems begin to collapse, this belief is collapsing along with them.
The fight against introduced species
Introduced species have their bad reputation for a reason. An assessment of every threatened species in Australia finds 82 per cent of them are threatened by introductions.1 Rabbits threaten the most species, root-rot fungus (phytophthora) comes in second, and pigs, cats and goats make up the rest of the top five. More than 30 native Australian mammals have become extinct in the past 200 years. It’s the highest rate of native mammal extinction in the world, and the loss is mainly attributed to the introduction of predator species. Cats and foxes get most of the blame, having killed off 22 native mammals across central Australia so far.
But there are many factors muddying our response to introduced species. Some introduced species are actively encouraged, despite their impact on native creatures—consider trout, sheep and wheat, for example. Conversely, some native animals are systematically killed because they affect the profitability of agriculture—koalas in blue gum plantations, wallabies who eat crops. The everydayness of our Australian human life kills native species behind the scenes, their habitat destroyed for our homes and farms, and creates habitat that suits new species such as mynas, brushtail possums and ibises, which we then demonise and try to remove.
The government spends a great deal on trying to control introduced species: in the 2011–12 financial year, the figure was $13.6 billion.2 Most conservationists would consider this money well spent, even if the bulk of it goes to protecting introduced agricultural species from introduced wild species, with far less dedicated to protecting native wild species from threatening invaders.3 Conservation-minded Australians are also generally supportive of grassroots efforts to remove introduced species, from rural children freezing cane toads4 to elderly suburbanites gassing Indian mynas.5 As the president of the Canberra Indian Myna Action Group says, ‘this bird is detested by everybody in the community because of what they perceive as its social nuisance: its raucous calls, its dirty habits’.
We spend a lot of money and effort on combatting introduced species. You might also say we live in a compromised ethical state because of it: control of animals is generally lethal—baiting, shooting, trapping and gassing—and conservationists can feel guilty about their role in so much death. It could all be worth it if it worked, if the introduced species were gone, if native species were left to survive and thrive. But increasingly, as the effects of white settlement have overwhelmed the systems that were here before we arrived, removing introduced species is not the solution it once was.
What is a native species?
The knee-jerk answer to the question: what is a native species? is anything that was here before 1788. But that is far from the only answer. Commonwealth legislation and that of most states define a native species as being ‘present in Australia or an external Territory before 1400’.6 The significance of this date appears to be lost to time—even the Department of Agriculture, Water and the Environment couldn’t say for sure, when I asked, what it meant or how it had been arrived at.
The more popular cut-off of 1788 suggests only Europeans deliberately move species out of their home range and into places more suited to humans. The arrival of the dingo sometime between 3500 and 5000 years ago,7 brought to this continent by Indigenous people, shows that is untrue, but it’s only the most obvious example.
In recent decades, white Australia’s understanding of the country, pre-colonisation, has had quite a shake-up. It was once popularly regarded as ‘natural’, a wilderness untouched by human hand until white people arrived. We are now finally listening to evidence about how the traditional owners of the land adapted and managed it, with Bruce Pascoe’s bestselling Dark Emu bringing together evidence for Indigenous husbandry of the landscape and showing how the traditional owners created what Bill Gammage calls ‘the biggest estate on Earth’. This pre-1788 landscape is a complex, human-altered system that needs continuing human management to stay ‘native’.
Then there are those who consider the 1788 cut-off to be too early. There are plenty of people—18 per cent of Australians—who say that brumbies (feral horses) are native to Australia.8 When I spoke to the researcher who discovered this, Lily van Eeden, she told me ‘there’s something about horses … They’re charismatic, they’re majestic; they’ve got this sort of charisma about them that drives people to love them. You could say the same thing about camels in Australia [that they’ve been here a long time and are part of Australia’s history], but no-one’s out there holding up placards saying “Save the camels”.’ Those who want to keep horses in alpine national parks will often cite their value as an ‘Australian species’ when arguing in their favour.
Being native matters
Take sugar gliders. They are undeniably cute. A ‘palm-size possum that can glide half the length of a soccer pitch’,9 they’re the kind of creature you want to pop in your pocket and feed delicious treats. Dangerfield even makes a sugar-glider-themed mini skirt.
They are also relentless predators of Tasmanian parrots. They crawl into the hollows where critically endangered swift parrots nest, and chomp down on eggs, nestlings and even full-grown mother birds. (Interestingly, they are less likely to do this in places where logging hasn’t occurred and where there is plenty of old-growth forest left.)10
Under Tasmanian law the sugar glider was, until recently, protected as a native species. This made it very difficult to do anything about the threat they were posing to a critically endangered bird. But in 2018 researchers used genetic and historical data to show that sugar gliders had been introduced from the mainland around 1835.11 As the researchers pointed out, this name change from native to introduced was the end of the line for gliders: ‘This information is critical in dealing with community and stakeholder concerns about management activities that may suppress sugar glider populations. It also expands the range of intervention options available to conservation managers.’ In other words, it was now fine to kill them. In September of that year, the Tasmanian government set up a program to catch and cull gliders. The gliders were still just as cute. Their behaviour hadn’t changed in any way. The only difference was that someone figured out they’d arrived in 1835 rather than before 1400.
Dingos are considered native by some people and some jurisdictions, but as introduced by others. This blurriness means the dingo is both persecuted and protected, sometimes in the same jurisdiction. When people attempt to defend the way they want to treat dingos—be that as pests or as Australian icons—they tend to cast the argument not in terms of its ecological importance but in terms of whether they consider the animal introduced or native. (Fights about whether dingos are ‘purely’ Australian or have bred with foreign dogs make the whole thing even more fraught and, frankly, embarrassing.)
Environmental social scientist, Lily van Eeden’s paper ‘Diverse public perceptions of species’ status and management align with conflicting conservation frameworks’ found we are less likely to want native species killed, but also more likely to insist a species is native if we want it to flourish.12 She told me: ‘There is a strong link between defining something as non-native and accepting its lethal control. If you think of something as a pest or not a pest, that’s linked with accepting its lethal control, same as defining things as native or non-native, and it goes both ways, those things influence each other: if you oppose something being killed you’re more likely to say, “no, this is native”, as people say with horses.’
Being native matters for a creature’s survival under Australia’s management systems. Around the world labelling something non-native, wherever it came from, is a standard approach to justify eradication: in Scandinavia there have been moves to rename wolves ‘Russian wolves’ and opponents of wolves in Yellowstone favour calling them ‘Canadian super wolves’.
Who are these invaders and where are they going?
While humans are busily remaking the world to suit us, other species are trying to get out of the way. Along with invasive species, land clearing is one of the biggest threats to species in Australia. Much of the country is becoming uninhabitable as we remove other species’ habitat to make way for our own—for agriculture, livestock, homes and roads. Projections suggest that between 3 million and 6 million hectares of forest will have been bulldozed in eastern Australia between 2019 and 2030 if we carry on at our current rate of clearing.13 As Kit Prendergast points out in her work on moving species from one area to another, ‘The historical range may no longer be suitable due to factors such as changing soil conditions as a result of erosion, livestock grazing or salinity; changes in vegetation structure due to introduced herbivores or drought; and changes in the biotic assemblages of predators, parasites, mutualistic species and food and shelter resources. The fact that species are already naturally shifting their ranges to keep within their climatic envelope suggests that keeping species within their historical distribution is not in line with ecological reality.’14
At least 25 per cent and perhaps as much as 85 per cent of Earth’s estimated 8.7 million species are already shifting ranges in response to climate change. On average per decade, species are moving towards the poles at 17 km on land and 78 km in the ocean.15 Everything (including me) is heading for Tasmania, and the fish are getting there first. Plants, of course, move much more slowly. In simple terms, ecosystems are being split apart as some members move on while others struggle to follow; fast-moving migrants find themselves in the remnants of a different ecosystem that is itself trying to move south. Species are meeting species they’ve never seen before. Food sources are missing, or more predators are present. There are new diseases and other threats. And once a few new species have moved in, they change the habitat to make it more receptive to other new arrivals.
Tasmania’s oceans are seeing the impacts of this already. Gretta Pecl, director of the Centre for Marine Socioecology at the University of Tasmania, says that ‘in the ocean around Australia we’ve documented 228 species that are shifting so far, and those are only the ones where we’ve actually gone and looked.’ Many fish species are arriving from farther north,16 some of them to the delight of Tasmania’s recreational fishers: the red snapper and the kingfish have proven particularly popular. Other marine species are shifting too, including the eastern rock lobster (Sagmariasus verreauxi) and the common Sydney octopus (Ocotopus tetricus), which are successfully breeding in the waters off Tasmania.17
Warmer waters have also expanded the range of the long-spined sea urchin (Centrostephanus rogersii), with devastating effects. Tasmania’s famous, unique east coast sea kelp forests have largely disappeared, thanks to a combination of warming, nutrient-poor waters and the hungry urchins. An ecosystem that supported many species of fish, invertebrates and sponges, as well as tourism operators, has crumbled. The urchin is widely loathed, but is it an introduced species? Humans haven’t physically picked it up and moved it, but our actions have shifted the climate and thus the urchin’s natural range, letting it move itself.
Children born now in eastern Tasmania will have never seen the kelp forests in their former glory, will have always known the urchins. Already a fishery is growing up around the species: the Tasmanian government has worked with the abalone industry, smashed by the new arrivals, to fish urchins. In 2019, 560 tons were caught and mostly exported. But this could create a challenge. People will gear up and invest in this industry, and after a while they won’t want the urchins totally gone. By the time kids today are grandparents, will they think of the urchins as native? Will urchin diving be a culturally important Tasmanian activity, the way deer hunting is now?
While some species are showing initiative and moving themselves, others will become stranded and face extinction. It is likely that some of these will be considered precious enough for us to help them make the move. ‘Assisted migration’ and ‘translocation’ are increasingly popular subjects for scientific enquiry, but species were moved for conservation reasons long before we knew climate change was a risk.
Lyre birds were introduced to Tasmania in small batches during the 1930s and 1940s by bird lovers who feared they would go extinct on the mainland due to foxes. It turned out foxes were not that much of a threat to mainland lyrebirds, but as the birds are now at risk thanks to climate change and bushfire, the move may have been prescient.18 Fifteen years ago it was estimated there were 8000 lyrebirds in Tasmania19 and they are now considered a threat to ecosystems of the Tasmanian Wilderness World Heritage Area. The Tasmanian environment department describes them as an ‘exotic pest species’.20 They are unloved and unwanted.
Meanwhile, koalas were introduced to Kangaroo Island, in South Australia, in the 1920s, due to fears they would become extinct on the mainland. By 1997 their population had blossomed to the point where a management plan had to be instituted to stop them eating all the manna gums on KI and subsequently starving to death (not to mention starving the other indigenous species that rely on the trees). The population is chlamydia-free, unlike all mainland populations, which means it has to be maintained, but by 2019 there were 50,000 koalas and a sterilisation program was well underway to try to keep numbers under control. Then in 2020 Kangaroo Island was ravaged by bushfire and perhaps 40,000 koalas were killed. Ecologists were relieved the population was back at a sustainable level. The public had other ideas: a crowdfund to ‘Help save Kangaroo Island koalas’ made $2.7 million and the resulting charity is now raising, treating and releasing koalas injured or orphaned in the fires to help boost the population again. As the charity says, ‘Kangaroo Island is well known for its thriving koala population however over 150,000 hectares has been lost due to recent events, this will effect [sic] our koala population dramatically. We need to pull together to save this Australian icon.’
Humans adapt to shifting baselines; it’s given us the ability to cope with all kinds of things. We take the world as we find it and try to make the most of things as they are. For many of us, our baseline is a landscape depleted of locally indigenous species, homogenised. The species we know about are the iconic ones—kookaburras, koalas and, perhaps, horses. They’re the ones that feel to us as if they belong, even if once they didn’t. Or, as one Tasmanian said to me about a bird that was introduced to the state in the early twentieth century, ‘Kookaburras have always been here, haven’t they?’
Can a species become native?
Not all species on the move create catastrophic effects in their new environments. Gretta Pecl tells me that ‘surprisingly few species so far have had those negative kinds of impacts in terms of ecosystem problems’. And there are other species that have begun providing important functions in their new ecosystems.
Some ecologists think our views on what we’ll accept as native will change as our landscapes become even more depopulated of the wild animals we now take for granted. The idea of ‘novel ecosystems’ was developed in 2013 by scientist Richard Hobbs, who described ‘a system … that, by virtue of human influence, differs from those that prevailed historically, having a tendency to self-organize and manifest novel qualities without intensive human management’,21 with the implication that management decisions should be based on the impacts of species, regardless of their origin.
What does this mean in Australia? Plant species such as prickly, yellow-flowered gorse and lantana, a mainstay of grandma hedges across suburbia, are introduced and widespread. Decades of attempts to remove them have been largely futile. They are here to stay. But more than that, they have become important in the survival of some native species. Little mammals and birds need shelter from predators such as feral cats. This shelter was once provided by tussocky grasses, but those are now gone from the landscape.
When land managers remove gorse or lantana, the small natives have nowhere left to hide and become a kind of cat buffet. So what’s the solution? Do we accept that the function of ‘small animal retreat’ is now provided by gorse, and just leave the gorse alone? As David Watson, professor in ecology at Charles Sturt University, said to me, bandicoot mothers don’t instruct their babies to ‘avoid exotic plants’. As long as it’s a safe place to be the bandicoots don’t care.
More controversially, Watson also questions our attitude to rabbits. ‘Those [native] mammals that are in the rabbit/hare size; they’re all burrowers. They’re either hanging on in little parts of WA or they’re gone forever. But rabbits have moved in and rabbits are that size and rabbits burrow. And there has been a handful of studies that have gone, well, wait a minute, how does a rabbit burrow compare to a burrowing bettong burrow or a bilby burrow, and is a burrow a burrow? So I’m not convinced that rabbits are all bad and I think in some systems … well, if you want to find a woma python in South Australia, find a rabbit warren. It’ll be in there.’
Similarly, there is evidence that native Australian species are learning to live with some introduced predators, foxes in particular, though they remain extremely vulnerable to cats.22 In Queensland, where northern quolls have lived with cane toads for 70 years, the quolls are learning not to eat the toxic invaders.23 Will there be a future where these relationships have stabilised enough that we consider foxes and toads native, like the once-introduced predator, the dingo?
It would be better to have native, extinct white-footed rabbit-rats than plain old rabbits or rats. And it would be better to have grasslands full of silver tussock than full of gorse. But is it realistic? In the case of the white-footed rabbit-rat, definitely not. As Karen Lips, a professor of biology at the University of Maryland, says, ‘There is no pristine, there’s no way to go back. The entire world is always very dynamic and changing. And I think it’s a better idea to consider just simply what is it that we do want, and let’s work on that.’24 Or as another ecologist I spoke to said, ‘There are ecological boundaries that are much more profound than our stupid lines on a map’.
The extreme future
David Watson and his co-author, ornithologist Maggie Watson, are interested in what will happen to species in the far, far future, after humans are gone25: the most optimistic futurists give us 7.8 million more years. Scientists estimate life will continue for about as long after humans as it did before humans—about another billion years—until eventually the conditions necessary to support multicellular life are gone. The continents will continue shifting until they are all one landmass, Panagea Proxima. It will be the end of any ideas of native or introduced, with land animals free to move themselves from one spot to the other as suits their needs.
Why should we care about this far-distant future? We have precipitated a sixth great extinction, but unlike the forces that caused the previous mass die-offs, we can, to an extent, make choices about what lives and dies. After previous extinctions, the species that survived spread reasonably quickly to fill the many vacant niches, but then took another 10 million years or so to diversify sufficiently for the number of species to bounce back to pre-extinction levels.26 We all know, vaguely, about the middle-sized mammal species that survived the asteroid that wiped out the dinosaurs and went on, more or less, to become us. When we are gone and most of what we know now is gone, which will be the species that hang on, fill the niches and eventually explode out into a proliferation of species that create the world’s new ecosystems? Those species, the Watsons propose, will likely be the introduced species we’re trying to exterminate.
‘Those same traits and ecological circumstances that render them invasive also make them more likely to survive the Anthropocene,’ they say. ‘If the class Amphibia persists, it’ll be thanks to cane toads—the only amphibians to thrive on multiple continents. Likewise for cacti and the prickly pear—the most widespread and climatically tolerant member of a family that is almost entirely listed as endangered. If the Testudines, Decapoda and Commelinales orders persist, it’ll be thanks to their most resilient ambassadors: redeared slider, signal crayfish and water hyacinth … Paradoxically, the world’s worst ferals are the most future-proof.’
Perhaps we need to consider this when thinking about which species should live and which should die—perhaps it won’t be entirely a case of native versus introduced when inevitably, due to climate change as of now and continental shift in the next few billion years, those ideas will become irrelevant. If we cull introduced species for being too successful, are we undermining the only plants and animals likely to make it through the next 1000 years? There’s little doubt we’ll soon have a world without lions and tigers and snow leopards—if we get rid of feral cats, are we dooming the world to an entirely cat-free future?
Why do we want a pure Australia?
What state are we trying to return Australia to when we argue for a removal of introduced species? Pre-brumby? Pre-European invasion? Pre-whatever it was that happened in 1400? Or are we hoping to go back to the Pleistocene, where megafauna roamed the continent and the Nullarbor was forested? Do we want to get rid of cane toads and cats, or sheep and wheat and pasture grass, or dingos, or humanity?
In southern Australia, native orchid species are under pressure from human-caused disruptions. Some species are responding, hybridising with other orchid species and becoming, arguably, new species better suited to these new conditions. For botanists, this can be an unpleasant and confusing situation. They would prefer to keep the original, native species: if the orchids are considered ‘impure’ they may no longer be protected. Among many humans there seems to be a deep discomfort with the idea of nature as a system that is forever in flux. We want to stick a marker in a particular time and say, ‘this is nature—let’s re-create it, then let’s never let it change again’.
Even those of us who accept evolution intellectually can find it uncomfortable emotionally—the idea that there is no perfect natural world, only a system that is always shifting and adapting, full of loss and creation; that a world where we don’t have elephants or whales or wedge-tailed eagles but where there is a profusion of different algae isn’t necessarily ‘wrong’, but just is what it is.
Unfortunately for us, the world is refusing to stand still. Our ideas of native and introduced are already shaky; our remaking of habitat and climate make them ever more irrelevant, with up to 85 per cent of species worldwide moving already, thanks to climate change. To an extent, the ambition to control—and even exterminate—introduced species is based in a simplistic and perhaps out-of-date view of Australia’s ecology. For many, it is driven by a guilty longing to return to a better time. We would like to restore Australian nature to how it was in 1788, to erase the mistakes white colonists have made since arriving here by removing the symptoms of our arrival—cats, foxes, rabbits, toads—without removing ourselves or the damage we’ve done by clearing, building and sowing. We don’t want to give up our settler lives in this country, our homes and agriculture, but we would like the embarrassing bloody corpses removed.
Jane Rawson writes novels, essays and stories, usually about animals or climate change. Her most recent novel is From the Wreck. She lives in Tasmania’s Huon Valley and works for a conservation organisation.
References.
1 See <https://www.publish.csiro.au/pc/Fulltext/PC18024?subscribe=false%22>.
2 See <https://neobiota.pensoft.net/article/6960/>.
3 Query sent to invasive species council.
4 See <https://www.brisbanetimes.com.au/national/queensland/thousands-killed-in-toad-day-out-
20141112-9fu0.html>.
5 See <https://www.canberratimes.com.au/story/6039557/canberra-indian-myna-action-groupcelebrates-10-years/>.
6 See <https://www.legislation.gov.au/Details/C2004C03797>.
7 See < https://www.sciencedirect.com/science/article/abs/pii/S2352409X16300694>
8 See <https://www.sciencedirect.com/science/article/abs/pii/S0006320719300357?dgcid=author>.
9 See <https://www.nationalgeographic.com/animals/mammals/s/sugar-glider/>.
10 See <https://theconversation.com/sugar-gliders-are-eating-swift-parrots-but-whats-to-blame-19555>.
11 See <https://onlinelibrary.wiley.com/doi/full/10.1111/ddi.12717>.
12 See <https://www.sciencedirect.com/science/article/abs/pii/S0006320719300357>.
13 See <https://theconversation.com/wwf-fires-awarning-shot-over-australias-land-clearingrecord-40952>.
14 See <https://onlinelibrary.wiley.com/doi/10.1111/aec.12926>.
15 See <https://theconversation.com/climatedriven-species-on-the-move-are-changingalmost-everything-74752>.
16 See <https://www.sciencedirect.com/science/article/pii/S0959378014002015>.
17 See <https://www.publish.csiro.au/mf/MF14126>.
19 See <https://www.abc.net.au/radionational/programs/saturdayextra/lyre-birds-feral-in-tasmania/3449828>.
20 See <https://dpipwe.tas.gov.au/Documents/Thynninorchis-nothofagicola-listing-statement.pdf>.
22 See <https://royalsocietypublishing.org/doi/10.1098/rspb.2018.0857>.
24 See <https://ensia.com/features/climate-change-nonnative-invasive-species/>.
25 See <https://www.sciencedirect.com/science/article/pii/S0169534719302952>.
