Friday essay: species sightings

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An echidna in the Western Granites at Jam Tree Gully.
John Kinsella

John Kinsella, Curtin University

A Rare Sight

The bird seen first time here
in forty years sings lightly
on the wire, you turn to touch
the shoulder of a friend
and turning back together
find nothing but sky
and wire trembling.

Brushtail possum evidenced. We had not seen one here in nine years, and there might not have been a sighting long before this. But there might have been. A possum or possums may have been driven out, removed from the roof cavity — there are, sadly, people who will do this and then exterminate them. But this too is conjecture, we’re only going here on the general condition of the bush block when we arrived — the 170 years of colonial erosion, the running of cattle and sheep and horses, the fencing, cropping (to a lesser extent because we are on the rocky northern face of a valley — that happens on the other side of the hills, a couple of kilometres away), and the machinery of colonial domestic presence — house, sheds, driveway, firebreaks.

Once, this area in the Western Australian wheatbelt, like nearby Goomalling (“Place of possums”), was prime habitat for brushtail possums. Even now residual and remnant York gum and jam tree woodland, granite boulders and granite outcrops, in patches of greater and lesser density, provide enough for native fauna to retain a hold.

Since we’ve been at Jam Tree Gully, we have removed internal fences, planted trees and — through not farming animals — allowed the beginning of a return of undergrowth. It’s an agonisingly slow process; this year is the first in nine years that we have actually seen, through self-generation, the reappearance of the shy sun orchid (a single example), scarlet runner (running postman) and a native fern.

Looking south across Jam Tree Gully.
John Kinsella

I am talking about Ballardong Noongar boodja (country), and not “ours” but by the colonial reality of surveys and land titles, “allocated” as our domestic jurisdiction, the act of survey and property hierarchising entitlement (though mining companies believe they have even more entitlement than that, as, of course, does the state, as anyone can tell you who had “their” land reclaimed as part of the Cathedral Avenue widening of the road from York to Quairading and the destruction of hundreds of old-growth salmon gums, wandoos and York gums). As far as I and my family are concerned, we have an obligation to return this land to a health that though distant from its pre-colonial state of health, at least gestures towards it.

One of the dominant linguistic behaviours of our family residency in the area, of our presence, is to discuss what other living things we see every day, and how they relate to the country we see them on. Our son Tim, an avid birdwatcher and naturalist, walks the block every day and reports back, verbally and on film, about what he’s observed. These are intricate and informed observations, cross-referenced with what is likely to be seen, differences in, say, behaviour (mating plumage, nesting processes, shifts in song, etc), numbers, and implication. Like his parents, Tim sees language as part of presence, and these observations are an essential part of his own poetry-making.

John Kinsella.
Tracy Ryan

Similarly, I spend my time out on the block doing restorative tasks and acts, and working their language into the matrix of my writing. The language is in flux because rather than a taxonomy, a nomenclature of seeing and presence, what happens is that experience of habitat loss, and attempts at habitat restoration, place words, syntax and utterance as we have it under pressure.

Something else emerges, an active language of presence that needs to critique the ironies of its own impact, of its own vicarious (and direct) participation in the ongoing dynamics of dispossession and acquisition.

Neologisms and new nomenclature might be one outcome, but more often it’s a shift in what constitutes the observing eye and voice, what makes the self in the process. In poetics, we talk about the “I” in the context of the unified self and challenging the primacy of personal observation when language itself creates at the very least a simulacrum of self in which the poem is a cybernetic producer of opinions, surprise correlations and yokings, undoings and interjections. The poem itself is alive — made by the writer, it takes on a life of its own.

So, does this mean I am suggesting the poem itself, for example, channels the disturbances and distresses of country? Well, yes, up to a point.

The wasp making its mud cells and inserting caterpillars or spiders, stunned but alive with a wasp egg laid inside their bodies, to be eaten alive — in a state of life suspended — by wasp grubs, which break out of their dark cells into the light.
It’s a poem that needs no explanation if “made” — it works on levels of allegory, symbol, a glimpse of habitat, and so on. Or maybe something a little more acceptable to a readership which ultimately looks for affirmation of connection with the natural world while benefiting from capitalist exploitation of place (look around us), an echidna moving rapidly downhill, its quills liquid in the fractured light of late afternoon sun streaming over the rim of valley, through the York gum canopy.

Read more:
Australia’s species need an independent champion

We don’t see echidnas often here, but we see evidence of their diggings for ants and termites almost daily. And we see their scats. In fact, coming across scats is how we identify so much, including the brushtail possum. Scats, footprints, scratchings and sounds, especially at night. These languages are outside direct encounter, and often outside a description we might offer. Echidna sightings are coming less often, though evidence of their presence remains strong.

The poem interprets this as avoidance and strategy on the part of the echidna — we respect the not-seeing, and delight in the evidence of presence. Same with kangaroos. But in the case of eagles, the (illegal) killing of an eagle in a pair that were resident for many, many years, is an undoing that is hard to resolve under habitat-loss pressure. It is brutal. But writing about this loss, about the wrong done, cannot be a fait accompli — it must believe in the imagined presence as likely “return” as species, at least.

Roos at Jam Tree Gully just before the fences came down.
John Kinsella

All life we see on the block is vulnerable to human violence — thrill-killings of animals are sadly not uncommon, and there seems a strong link between far-right politics of patriotism and shooting around the district.

Scramble-biking, bush-bashing and remorseless clearing are changing habitat around the zone we “protect” at a far greater pace than when we arrived. It’s easy to use the “fly-in fly-out” dynamic as a distraction for the massive abuse that mining is in Australia, and to separate social issues of employment and purpose when discussing the obvious (“clear-cut”) environmental abuses of miners and their protectors, but nonetheless it is a real impact on ecologies that needs to be factored in.

The psychology of the mine

The impact of flying, the obvious impacts of the mines themselves, but also the psychology of purchasing a country property within a couple of hours’ reach of the city airport to use as a base. So many of the farmlets and blocks around where we live appear to have been bought by FIFO (fly in fly out) workers (real estate ads often overtly pitch to FIFO buyers, and I offer anecdotal evidence of conversations direct and indirect with and involving neighbours), and in many circumstances the psychology of the mine looks as if it has been brought to those blocks — substantial bush clearing, clear indifference to wildlife, and a psychology of control, ownership and what manifests by intent or default as a disrespect of Aboriginal land rights.

Of course, such attitudes to country are not unique to FIFO miners, far from it, and they have found around them a context of receptivity to such ways. And I do not blame the individual miners for this per se, but I do blame the mining companies and those who facilitate the abuses of land by those miners. A work psychology too readily becomes a life psychology.

An Inland Thornbill at Jam Tree Gully.
John Kinsella

In creating writing that acts as witness to species loss, we too easily become contributors to the archive, to the seedbank of metaphors that substitute for the real thing. It’s like repugnant natural history collections that give us a record of so many lost species when the very process of collecting has been a part of that species loss. Science bears many moral ironies that I feel an active, restorative poem should not. I am not saying a poem shouldn’t ironise the limitations of its own production, its impacts on ecologies; in fact, the opposite. I am saying it should be aware of them and critique its own role in the destruction.

A poem having a role in destruction? I hear you wonder. How so? Because industrialised consumer life is impacting and many, even the most environmentally-minded, make their art through the tools of exploitation.

It becomes a question of genuinely weighing up the cost in terms of the benefit to the environment. Does getting the message out there regarding habitat destruction cost more morally and literally than not doing so? The notion of “costs” needs to be placed under pressure before we begin. An economics of the figurative needs to be held accountable, scrutinised.

Read more:
More sightings of an endangered species don’t always mean it’s recovering

Which brings me back to the language of participation, observation and instruction I intimated when talking of our son Tim and writing what’s happening on the block. My partner Tracy and I are often confronted with the horror of having to say, “We saw a lot of those (birds, mammals, insects, reptiles, trees, shrubs, flowers etc) when we were kids, but not often now, or not at all.”

In many cases, flora and fauna we knew as children are now endangered or verging on extinction, not only within the physical areas with which we were most familiar, but across their range.

An example is the brown bittern, which I used to see and hear as a child when around swampy areas, and which is now almost extinct, certainly in the Northam region. Yet Tracy and I, travelling with Tim, had the remarkable experience of very likely seeing (unconfirmed sighting) a black or brown bittern between Toodyay and Perth last year. Tim, a most observant person, didn’t see it because he was studying something else outside the opposite window, and has been quizzing us about the sighting ever since. He has done a vast amount of research, and we have considered all other possibilities (too big for a little bittern, not the right size and shape for a night heron, a bird I know well), and so on. It was really, a notifiable sighting. Not in the sense of an “invasive species” (the irony!), but as an almost extinct species.

Echidna in the Western Granites.
John Kinsella

Would such notification lead to an invasiveness that affected its habitat more, or would it lead to protection? I consider recent sightings of night parrots in northern Australia, and wonder. The “understanding” to “save” can be so destructive — life, persisting against the odds, suddenly disturbed, fetishised, made vulnerable with over-attention. The “leave alone and stay away” approach can often be more effective. At least until the bulldozers arrive, which I’ve learnt over my life is eventually.

So, what do we do? Write a poem of resistance, of embodying the bird but not appropriating it in a poem, of keeping an eye on habitat and acting if it looks under threat?. Where a creature once was, a creature might be. Belonging and the marks of the endemic cannot be erased entirely with all the brutal means of survey and development, though the modus operandi of the state and its private apparatuses is to achieve that, and to convince us it’s been achieved. They want no comeback, to retrospective protections, and certainly no memorialising that cedes authority.

Brushtail possum evidenced. The nature of our interaction yet to be decided — largely by possum, but also by us. Possum enters poems, enters essays, enters stories. But does it become just a word, just an idea separated from its living life, it’s actuality? So easily, yes. Yet tense has a lot to do with it. As an active presence, not a thing of the past, and as a generator of sounds, movement and language. It is not an addition to here; it is here. It is not an exercise of painting a landscape; it is the land.

Read more:
Hidden housemates: when possums go bump in the night

Language used in the poem needs to be alive to the visceral, to a future in which it is not archival but an active presence, a declaration of rights. How can this be achieved? That poem is trying to write itself at the moment, and is finding its feet, its fur, its eating-places and shitting-places. There is an obligation in how we write, and a social implication in all we write.

In the community of the poem, which is both inside the text and outside, a knowledge of species loss and its prevalence might inform an observing, interaction with and imagining of a creature (or plant) as not only at risk, and on the verge of loss, but also as a resistance to collecting, archiving and relegating. The creature isn’t “was” but “is”, always now. We, the readers and hearers, participate in the speech-making of the poem, participate in this “imagining, and acting, in a world”. There’s one biosphere of many worlds. In our writings we need to make the leaps, the segues, the conversations between the one and the many. Brushtail possum evidenced. Listen, listen — on the roof, now, tomorrow!

The ConversationThis is an edited version of a paper given at the Australian Academy of the Humanities’ 48th Annual Symposium, Humanitarianism and Human Rights, held November 15 to 17, 2017, in Western Australia. The poem A Rare Sight is from John Kinsella’s The Silo: A Pastoral Symphony (Fremantle Press, 1995).

John Kinsella, Professor of Literature and Environment, Curtin University

This article was originally published on The Conversation. Read the original article.


‘Epic Duck Challenge’ shows drones can outdo people at surveying wildlife

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A drone image of a breeding colony of Greater Crested Terns. Researchers used plastic bird decoys to replicate this species in an experiment that compared different ways of counting wildlife.
Jarrod Hodgson, CC BY-ND

Jarrod Hodgson, University of Adelaide; Aleks Terauds, and Lian Pin Koh, University of Adelaide

Ecologists are increasingly using drones to gather data. Scientists have used remotely piloted aircraft to estimate the health of fragile polar mosses, to measure and predict the mass of leopard seals, and even to collect whale snot. Drones have also been labelled as game-changers for wildlife population monitoring.

But once the take-off dust settles, how do we know if drones produce accurate data? Perhaps even more importantly, how do the data compare to those gathered using a traditional ground-based approach?

To answer these questions we created the #EpicDuckChallenge, which involved deploying thousands of plastic replica ducks on an Adelaide beach, and then testing various methods of tallying them up.

As we report today in the journal Methods in Ecology and Evolution, drones do indeed generate accurate wildlife population data – even more accurate, in fact, than those collected the old-fashioned way.

Jarrod Hodgson standing in one of the replica colonies of seabirds constructed for the #EpicDuckChallenge.
S. Andriolo

Assessing the accuracy of wildlife count data is hard. We can’t be sure of the true number of animals present in a group of wild animals. So, to overcome this uncertainty, we created life-sized, replica seabird colonies, each with a known number of individuals.

From the optimum vantage and in ideal weather conditions, experienced wildlife spotters independently counted the colonies from the ground using binoculars and telescopes. At the same time, a drone captured photographs of each colony from a range of heights. Citizen scientists then used these images to tally the number of animals they could see.

Counts of birds in drone-derived imagery were better than those made by wildlife observers on the ground. The drone approach was more precise and more accurate – it produced counts that were consistently closer to the true number of individuals.

Comparing the vantages: drone-derived photographs and the ground counter’s view.
J. Hodgson

The difference between the results was not trivial. Drone-derived data were between 43% and 96% more accurate than ground counts. The variation was due to how many pixels represented each bird, which in turn is related to the height that the drone was flown and the resolution of the camera.

This wasn’t a surprise. The experienced ground counters did well, but the drone’s vantage point was superior. Observing photos taken from above meant the citizen scientists did not have to contend with obscured birds that often occur during ground counts. The imagery also benefited the citizen scientists as they could digitally review their counts as many times as they needed. This reduced the likelihood of both missing an individual and counting an individual more than once.

The scientists were assisted by many volunteers, without whom the #EpicDuckChallenge would not have been possible.
J. Hodgson

However, even though it proved to be more accurate, making manual digital counts is still tedious and time-consuming. To address this, we developed a computer algorithm in the hope that it could further improve efficiency without diminishing data quality. And it did.

We delineated a proportion of birds in each colony to train the algorithm to recognise how the animal of interest appeared in the imagery. We found that using 10% training data was sufficient to produce a colony count that was comparable to that of a human reviewing the entire scene.

This computerisation can reduce the time needed to process data, providing the opportunity to cut the costs and resources needed to survey wildlife populations. When combined with the efficiencies drones provide for surveying sites that are hard to access on foot, these savings may be considerable.

Using drone monitoring in the field

Our results have important implications for a range of species. We think they are especially relevant to aggregating birds, including seabirds like albatrosses, surface nesting penguins and frigatebirds, as well as colonial nesting waterbirds like pelicans.

Other types of animals that are easily seen from above, including hauled-out seals and dugongs, are highly suited to drone monitoring. The nests or tracks of animals, such as orangutans and turtles, can also be used to infer presence.

Additional experiments will be useful to assess the ability of drones to survey animals that prefer to stay hidden and those within complex habitats. Such assessments are of interest to us, and researchers around the globe, with current investigations focused on wildlife such as arboreal mammals and cetaceans.

We are still learning about how wildlife react to the presence of drones, and more research is required to quantify these responses in a range of species and environments. The results will help to refine and improve drone monitoring protocols so that drones have minimal impact on wildlife. This is particularly important for species that are prone to disturbance, and where close proximity is not possible or desirable.

Read more:
How drones can help fight the war on shark attacks

The world is rapidly changing, with many negative outcomes for wildlife. Technology like drones can help scientists and managers gather data fast enough to enable timely assessment of the implications of these changes.

The ConversationWhen monitoring wildlife, increasing the accuracy and precision of animal surveys gives us more confidence in our population estimates. This provides a stronger evidence base on which to make management decisions or policy changes. For species and ecosystems threatened with extinction or irreparable damage, such speedy action could be a literal lifeline.

Jarrod Hodgson, PhD Candidate, University of Adelaide; Aleks Terauds, Senior Research Scientist / Section Head, and Lian Pin Koh, Professor, University of Adelaide

This article was originally published on The Conversation. Read the original article.

Polar invasion: how plants and animals would colonise an ice-free Antarctica

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Tom Hart, Author provided

Peter Convey, British Antarctic Survey and Tom Hart, University of Oxford

Antarctica’s ice sheets could totally collapse if the world’s fossil fuels are burnt off, according to a recent climate change simulation. While we are unlikely to see such a dramatic event any time soon, we are already observing big changes and it’s worth considering what the worst case scenario might look like for the continent’s ecosystems. How long before Antarctica turns into grassy tundra?

For now, life thrives mostly at the very edge of the continent – it’s driven by the plankton-rich Southern Ocean and clustered around seasonally ice-free areas of coastal land. The interior might be sparsely inhabited, but the continent is not as barren as many think. There are around 110 native species of moss and two flowering plants, the Antarctic hairgrass and pearlwort. These plants have flourished along the relatively mild Antarctic Peninsula in recent decades. However they can’t go much further – they already occur at almost the most southern suitable ice-free ground.

With ice-caps and glaciers receding already in the Peninsula region, native land plants and animals are benefiting from more easily available liquid water. Already we are starting to see increased populations, greater areas occupied and faster growth rates, consequences only expected to increase – everything is currently limited by the extreme physical environment.

The world’s most southerly flower, the Antarctic hairgrass (Deschampsia Antarctica)
British Antarctic Survey, Author provided

It may eventually prove too warm for some native species, but the bigger issue in upcoming decades and centuries will be whether new and currently “non-native” species will arrive that are stronger competitors than the native organisms.

Antarctic invasions

Native polar species are inherently weak competitors, as they have evolved in an environment where surviving the cold, dry conditions is the overriding selective pressure rather than competition from other biological sources. If humans (or other wildlife expanding their range southwards) bring new competitors and diseases to Antarctica, that may pose a very grave risk to the existing biodiversity. Some native species would likely be pushed into the remaining more extreme regions where they can avoid competition and continue to rely on their inherent stress tolerance abilities.

Tom Hart with two million chinstrap penguins. Isolation has made Antarctic species vulnerable to introduced competition.
Richard White, Author provided

We usually split the process of natural colonisation – which applies even today in Antarctica – and that of movement of “alien” species by human agency. The best available data for the Antarctic region come from some sub-Antarctic islands, where it appears humans have been responsible for many more successful colonisations than nature. In fact, over the recent centuries of human contact with the region we have introduced 200-300 species compared to just two or three known natural colonisations.

Penguins, seals and flying seabirds move between islands and the Antarctic Peninsula, so there is potential for some natural colonisation. Vagrant birds are regularly observed across the sub-Antarctic and even along the Peninsula, some of which have colonised successfully (such as the starlings, redpolls and mallard ducks on Macquarie Island).

Migrants such as skuas and gulls, which spend time on land at both ends of their migration, could be important natural vectors of transfer for invertebrates, plant seeds and spores, and microbes into an ice-free Antarctica. Importantly, bird colonies also fertilise surrounding rock and soil with faeces, eggshells and carcasses. Plant and animal life flourishes near seabird colonies, encouraged by this enrichment.

What’s hitching a ride on this skua?
Tom Hart, Author provided

However it can be tough to predict what Antarctic melt would mean for individual species, never mind entire ecosystems. Take penguins, for instance – they have already survived previous inter-glacial retreats, but at reduced population sizes. This time round it is likely that Adélie and emperor penguins who are more dependent upon sea ice would decline, while less ice-dependent species such as gentoos and chinstraps might benefit. Indeed, there is already some evidence that emperors are struggling (although also that they may be adapting and learning to emigrate).

However the fact fish-eating gentoo penguins are increasing on the Peninsula while Adélies and chinstraps (both krill eaters) aren’t doing so well suggests prey availability can be more to blame than ice cover. Figuring out the impact of large-scale environmental change at ecosystem or food-web level is hard – it’s a complex process that will no doubt throw up some unexpected results.

This flightless midge comes from South Georgia but has been introduced further south.
British Antarctic Survey, Author provided

The sub-Antarctic islands are full of examples of such unexpected impacts. Pigs, dogs, cats, sheep, reindeer and rabbits have all been intentionally introduced in the past, with often devastating effects. Rats and mice were introduced to South Georgia and other islands accidentally by sealers and whalers, for instance, and have decimated seabird populations. A recent eradication campaign appears to have been successful and pipits, ducks and small seabirds are showing some immediate signs of recovery.

The removal of non-native cats from Macquarie and Marion Islands has similarly helped native burrowing seabirds, although responses in such ecosystems can be far more complex and unpredictable – the removal of cats from Macquarie also led to increase in the introduced rabbit population, and considerably increased damage to sensitive native vegetation.

Antarctic biodiversity is far more complex than widely assumed, with up to 15 distinct biogeographic regions that have been evolutionarily isolated for many millions of years. Humans present the greatest threat, not only of introducing new species, but also of moving “native” species between regions within Antarctica. This could be even more damaging, as these native species would already be pre-adapted to polar life.

Visitors to Antarctica are subject to increasingly strict biosecurity measures but accidental introductions continue to occur, often through food shipments for scientists. Changes in sea and land ice affect access to new areas, so we can only expect plant and invertebrate invasions to increase unless biosecurity becomes more effective.

The ConversationWhile cost issues may be raised, it is worth remembering that prevention will always be better – and cheaper – than subsequent control and eradication, even if such action is possible.

Peter Convey, Terrestrial Ecologist, British Antarctic Survey and Tom Hart, Penguinologist, University of Oxford

This article was originally published on The Conversation. Read the original article.


South Africa should sort out the bad from the really bad on its invasive species list

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Managing trout is a contentious issue with conflicting views about whether they pose a risk, or are beneficial.

Tsungai Zengeya, South African National Biodiversity Institute

This article is the third in a series The Conversation Africa is running on invasive species.

Alien species have been introduced to Africa for a variety of reasons. They provide food, raw materials for industry, ornamental plants, recreation in the form of sport fishing, hunting and pets. Some that are highly valued have been moved around widely. And in some areas they now form prominent components of societies and ecosystems like the domestic cat for example.

Many alien species bring considerable benefits. But some have become invasive, causing a loss of biodiversity, changes to ecosystems, economic losses and, in some cases, even affecting people’s health.

The shrub Prosopis or mesquite is an example. It was introduced to South Africa to provide fodder, firewood and shade in arid parts of the country. But it’s also a major water user. And two trout species (S. trutta and O. mykiss) are used for recreational angling and commercial aquaculture. But they’ve also been implicated in having a negative effect on the environment.

Managing invasive species is therefore critical. In South Africa the movement and use of 552 listed invasive species are managed under the Biodiversity Act and regulations attached to it. But not all the species on the list are equally harmful. Several may in fact be relatively harmless.

All the listed species under these regulations require management. Given that the capacity is limited, regulations should arguably focus on priority species because not all are necessarily harmful to the extent that would justify spending large amounts of time and effort on keeping them under control.

The question then is: are there some species that could be removed from the list? In our recent study we set out to answer this question by classifying species as inconsequential, beneficial, destructive or conflict generating species. This was done by assessing the relative degree of benefit they brought and their negative effects.

Beneficial and harmful species

The classification was done by using a simple scoring system. It had two categories for the negatives (ecological and socio-economic) and two for the benefits (economic and intrinsic).

  1. Inconsequential species: these make up 55% of the species listed under the act and in the regulations. They were associated with relatively low costs and low benefits to society. Species in this group had limited distribution or no known impact and were largely introduced as ornamentals or pets. Some examples include the eastern grey squirrel (Sciurus carolinensis), European perch (Perca fluviatilis), and the Père David’s Deer (Elaphurus davidianus).

  2. Destructive species: these make up 29% of the list. They don’t bring substantial benefits to society or the environment, but they have a highly negative impact. Many were introduced accidentally and are regarded largely as pests and weeds. Examples include invasive rodents like the black rat (Rattus rattus) which causes damage to infrastructure and transmission of zoonotic diseases and pitch canker (Fusarium circinatum) a growing threat to pine plantations and forests worldwide.

The jacaranda is an iconic tree species in the city of Pretoria where it’s regarded as part of the identity.
  1. Beneficial species: they make up 10% of the list and have clear social or environmental benefits. For example the jacaranda (Jacaranda mimosifolia) is an iconic tree species in the city of Pretoria where the species is regarded as part of the identity and “sense of place” of the city. Active management is not necessary or should only be done in particular cases.

  2. Conflict-generating organisms: these can be either beneficial or destructive, depending on one’s perspective or what value is placed on them. They make up only 6% of the list. There’s huge disagreement about whether these species should be controlled, or how they should be controlled. Examples include woody plants introduced for forestry, erosion control, sand dune stabilisation, agriculture and as ornamentals. Acacias and pines are examples. Animal examples include species like the Himalayan tahr which was introduced to the Table Mountain National Park. The goat has been the focus of eradication attempts, despite strong opposition. It also includes species introduced for aquaculture like maroon and brown trout. Managing trout has been highly contentious with conflicting views about whether they pose a risk, or deliver a benefit. This has led to them being listed and delisted. The trout fraternity refuse to acknowledge that trout are invasive species and highlight the lack of scientific evidence of the risks they pose.

Finding common ground

We need to keep sight of the fact that there is general agreement on 94% of listed species. By identifying the small number that are generating the greatest tension, it’s more likely discussions can be held to reach common ground on regulation.

Most countries in Africa don’t have invasive species regulations. But there’s growing recognition that they’re needed. South Africa offers useful lessons on how this could be done.

The control of species listed under the country’s biodiversity act is compulsory. This means that plans to manage them have to be drawn up and implemented. But this doesn’t seem sensible given that not all are equally harmful and resources are limited. Our study suggests that some of the species currently regulated could be removed from the list.

Countries wanting to set up a system of managing invasive species could start by classifying a prospective list of candidates. Policymakers could then quickly bring out legislation against the most damaging and destructive ones. At the same time, discussions could be had on the ones that generate conflict with the aim of reaching consensus.

The ConversationThis would allow managers and regulators to focus on the most destructive species – as well as those that are at the centre of fierce disagreement.

Tsungai Zengeya, Researcher at the South African National Biodiversity Institute, South African National Biodiversity Institute

This article was originally published on The Conversation. Read the original article.


Alien animals and plants are on the rise in Africa, exacting a growing toll

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The larger grain borer beetle attacks crops like maize and cassava, threatening food security.

Katelyn Faulkner, University of Pretoria; Brett Hurley, University of Pretoria, and Mark Robertson, University of Pretoria

This article is the first in a series The Conversation Africa is running on invasive species.

Let’s say you’re travelling from Uganda to South Africa for business. You finally arrive at your hotel after a long day and decide to change before dinner. You unlock and unzip your luggage, but there’s something in your bag that you didn’t pack. As you reach for a clean shirt, a moth flies out. Did that come with you all the way from Uganda? It’ll be fine, right? Surely, something so small won’t cause any harm.

Species are intentionally or accidentally transported by humans between continents to regions where they are not native. With the help of humans or by natural means like flight, these alien species can also spread within continents.

Their spread within continents can be rapid, affecting both the ecology as well as societies and the economy. Unfortunately, it’s really challenging to prevent species from spreading. Given the vast amount of people and goods that are transported between and around continents they can easily be moved across oceans as well as between countries.

The spread of alien species within Africa is increasing. Since 2000 more alien insect pests of eucalyptus trees have spread to other African countries from South Africa, than have been introduced to these African countries from other continents. To manage the spread of these alien species countries need to co-operate, communicate and share information and skills..

The spread of alien species

Many alien plants and animals have been introduced to Africa from other regions and then have spread from country to country, often having devastating effects.

Take the larger grain borer beetle, (Prostephanus truncatus) which is thought to have arrived on the continent in imported grain from Mexico and central America. The beetle was introduced to Tanzania before 1984, Togo before 1981 and Guinea before 1987. It then spread across the continent and within 20 years could be found further south in South Africa.

The beetle attacks crops such as maize and cassava, threatening food security and the livelihoods of the poor. Infestations often destroy maize that’s been stored by farmers, forcing them to buy maize as well as lose income they could have earned from selling any excess.

But alien species don’t just arrive from abroad. Many that are native to parts of Africa have also spread to countries on the continent where they are not native.

An example is the fish commonly known as the Mozambique tilapia (Oreochromis mossambicus) which is native to rivers on the east coast of southern Africa. Fishermen have transported the Mozambique tilapia to other areas and it is now found in river systems in southern and western South Africa and Namibia.

The Mozambique tilapia is a popular species for fishing but it can pose a threat to native fish and has been responsible for the disappearance of native species in some regions.

The spread of alien species within Africa is by no means a new thing. For instance, the bur clover (Medicago polymorpha), a plant from northern Africa, might have been accidentally transported by humans to South Africa as early as 760 AD.

A high and increasing threat

Recently a number of alien species have spread extremely rapidly across the continent, posing a particularly high threat to food security and livelihoods.

The fall armyworm, native to the Americas, was first recorded in west and central Africa in early 2016 and then in South Africa in January 2017.

One is a caterpillar known as the fall armyworm (Spodoptera frugiperda). The species, native to the Americas, was first recorded in west and central Africa in early 2016 and then in South Africa in January 2017.

The moths of the armyworm are strong fliers and the species may have spread through flight to South Africa from other African countries. Although the species attacks a wide range of crops, it poses a particularly serious threat to grain farmers. It is extremely difficult to manage.

Another example is a wasp known as the bluegum chalcid (Leptocybe invasa), which is native to Australia. In 2000 it was detected in Israel and shortly afterwards it was reported in Uganda and Kenya. From there it spread rapidly to many African countries including Zimbabwe, Mozambique, and Tanzania and was finally detected in South Africa in 2007. The insect probably reached Israel on live plant material and spread into Africa the same way, or was carried by people travelling between countries.

The wasp causes swelling or growths on eucalyptus trees, which can lead to decreased growth and tree death. As eucalyptus trees are an important source of income and fuel, this species could have an impact on the livelihoods of locals in these countries.

Preventing the introduction and spread

Once a species is introduced to one African country it’s highly likely it will spread to others on the continent because borders checks are weak.

The introduction and spread of species could be reduced if countries introduced biosecurity systems. These are used extensively in countries like Australia and New Zealand and involve using technology to check for alien species when people and goods enter a country. In Australia this involves inspecting goods, vehicles and luggage before they enter the country.

But even these systems aren’t a guarantee that species won’t spread. African countries would need to work together and share information and skills. This would also allow countries to prepare for the arrival of species, and to draw up plans to reduce their impact.

The ConversationThis is a tall order. But as a country’s defence against alien species introductions is only as strong as that of its neighbours, such action would benefit all of the countries involved.

Katelyn Faulkner, Postdoctoral research fellow, University of Pretoria; Brett Hurley, Senior Lecturer Zoology and Entomology, University of Pretoria, and Mark Robertson, Associate Professor Zoology & Entomology, University of Pretoria

This article was originally published on The Conversation. Read the original article.


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