The diet of invasive toads in Mauritius has some rare species on the menu



The invasive guttural toad.
Author supplied.

James Baxter-Gilbert, Stellenbosch University

The guttural toad (Sclerophrys gutturalis) is a common amphibian found in much of sub-Saharan Africa, from Angola to Kenya and down to eastern South Africa. With such a wide geographic range, and a liking for living in human-disturbed areas, it’s often seen in people’s backyards. Around gardens it can be thought of as a helpful neighbour, as it is a keen predator of insects and other invertebrates that may try to eat plants. Yet it also has the potential to be ecologically hazardous outside its native range – and this toad is an accomplished invader.

In the Mascarene Archipelago in the Indian Ocean, far from mainland Africa, these toads have been an established invasive species for almost 100 years. In 1922, the director of dock management in Port Louis, Mauritius, deliberately released guttural toads in an attempt to control cane beetles – a pest of the country’s major crop, sugar cane. This attempt at biocontrol failed, but the toads appeared to thrive and rapidly spread across the island.

Mauritius had no native amphibian species for it to compete with, and no native predators with a recent evolutionary history with toads. In mainland Africa these toads would have to divide resources, like food, with a host of native amphibians and deal with an array of native birds, mammals and snakes that evolved feeding on them. But without these challenges on Mauritius, the toads colonised the entire island rapidly.

Most toads are generalist predators and hunt a wide variety of prey, more or less eating whatever they can fit in their mouth. So as the guttural toad’s population numbers grew through the decades, so too did the concerns from Mauritian ecologists about the impact on native fauna. Anecdotal accounts as early as the 1930s suggest that the toads were having a negative impact on endemic invertebrate populations. In fact it has been suggested that the toads may have been a driver in the decline, and possible extinction, of endemic carabid beetles and snails.

But it’s only recently that the toad’s diet in Mauritius has been examined closely. In our new study we examined the stomach contents of 361 toads collected in some of the last remaining native forests of Mauritius.

By knowing more about what species the toads are eating, and which groups they favour, our research may help inform toad control actions to protect areas with known sensitive species.

In the belly of the beast

Through our research we were able to identify almost 3,000 individual prey items, encompassing a wide variety of invertebrates like insects, woodlice, snails, spiders, millipedes and earthworms.

This research also went one step further to examine the prey preference of the toads. In general, they seemed to favour, some of the more abundant and common prey species. These included ants and woodlice, which made up about two-thirds of their overall diet.

These findings may suggest that the toads were able to identify a readily available food source, and this may have fuelled their invasive population growth. Yet they are also eating prey that represents a more serious conservation concern.

Inside the toads we found 13 different species of native snail, most of which were island endemics. Four species are listed as being vulnerable to extinction and one, Omphalotropis plicosa, being critically endangered – having been presumed extinct until it was rediscovered in 2002. Understandably, we found it very troubling to find a “Lazarus species” within the stomach of an invasive predator.

Unanswered questions

These early insights into the native species now being hunted by a widespread and voracious predator raise new research questions. To understand the greater impact the toads are having on native species much more work is required to understand their prey’s population dynamics so we can determine if the toad’s invertebrate “harvest” is contributing to declines.

Furthermore, how does the toad’s invasive diet in Mauritius compare with that of other invasive populations, like those in Réunion or Cape Town – is their invasive success linked to a common prey type? And how does it compare with their diet in their own native species range?

Our study could only examine what they are eating currently, but Mauritius has seen numerous species decline over the past 100 years. What role did the toad play in these losses? Perhaps they historically fed more readily on creatures that were more abundant in the past, but had to switch their favour to ants and woodlice when the populations of other species dropped. We may never know.

What is clear is that there is much to learn about the habits of this far-from-home amphibian and its impact on the ecosystems it has invaded.The Conversation

James Baxter-Gilbert, Postdoctoral Fellow, Centre for Invasion Biology (C·I·B), Department of Botany & Zoology, Stellenbosch University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Humans are changing fire patterns, and it’s threatening 4,403 species with extinction



The Leadbeater’s possum, one of thousands of species threatened by changing fire regimes.
Shutterstock

Luke Kelly, University of Melbourne; Annabel Smith, The University of Queensland; Katherine Giljohann, University of Melbourne, and Michael Clarke, La Trobe University

Last summer, many Australians were shocked to see fires sweep through the wet tropical rainforests of Queensland, where large and severe fires are almost unheard of. This is just one example of how human activities are changing fire patterns around the world, with huge consequences for wildlife.

In a major new paper published in Science, we reveal how changes in fire activity threaten more than 4,400 species across the globe with extinction. This includes 19% of birds, 16% of mammals, 17% of dragonflies and 19% of legumes that are classified as critically endangered, endangered or vulnerable.




Read more:
Click through the tragic stories of 119 species still struggling after Black Summer in this interactive (and how to help)


But, we also highlight the emerging ways we can help promote biodiversity and stop extinctions in this new era of fire. It starts with understanding what’s causing these changes and what we can do to promote the “right” kind of fire.

How is fire activity changing?

Recent fires have burned ecosystems where wildfire has historically been rare or absent, from the tropical forests of Queensland, Southeast Asia and South America to the tundra of the Arctic Circle.

Exceptionally large and severe fires have also been observed in areas with a long history of fire. For example, the 12.6 million hectares that burnt in eastern Australia during last summer’s devastating bushfires was unprecedented in scale.

The post-fire landscape in Flinders Chase National Park, Kangaroo Island, three months after an extremely large and severe bushfire last summer.
Luke Kelly

This extreme event came at a time when fire seasons are getting longer, with more extreme wildfires predicted in forests and shrublands in Australia, southern Europe and western United States.

But fire activity isn’t increasing everywhere. Grasslands in countries such as Brazil, Tanzania, and the United States have had fire activity reduced.

Extinction risk in a fiery world

Fire enables many plants to complete their life cycles, creates habitats for a wide range of animals and maintains a diversity of ecosystems. Many species are adapted to particular patterns of fire, such as banksias — plants that release seeds into the resource-rich ash covering the ground after fire.

But changing how often fires occur and in what seasons can harm populations of species like these, and transform the ecosystems they rely on.

We reviewed data from the International Union for Conservation of Nature (IUCN) and found that of the 29,304 land-based and freshwater species listed as threatened, modified fire regimes are a threat to more than 4,403.

Most are categorised as threatened by an increase in fire frequency or intensity.

For example, the endangered mallee emu-wren in semi-arid Australia is confined to isolated patches of habitat, which makes them vulnerable to large bushfires that can destroy entire local populations.

Likewise, the Kangaroo Island dunnart was listed as critically endangered before it lost 95% of its habitat in the devastating 2019-2020 bushfires.

Large bushfires threaten many birds, such as the mallee emu-wren.
Ron Knight/Wikimedia, CC BY

However, some species and ecosystems are threatened when fire doesn’t occur. Frequent fires are an important part of African savanna ecosystems and less fire activity can lead to shrub encroachment. This can displace wild herbivores such as wildebeest that prefer open areas.

How humans change fire regimes

There are three main ways humans are transforming fire activity: global climate change, land-use and the introduction of pest species.

Global climate change modifies fire regimes by changing fuels such as dry vegetation, ignitions such as lightning, and creating more extreme fire weather.

What’s more, climate-induced fires can occur before the dominant tree species are old enough to produce seed, and this is reshaping forests in Australia, Canada and the United States.

Humans also alter fire regimes through farming, forestry, urbanisation and by intentionally starting or suppressing fires.

Introduced species can also change fire activity and ecosystems. For example, in savanna landscapes of Northern Australia, invasive gamba grass increases flammability and fire frequency. And invasive animals, such as red foxes and feral cats, prey on native animals exposed in recently burnt areas.




Read more:
Fire-ravaged Kangaroo Island is teeming with feral cats. It’s bad news for this little marsupial


Importantly, cultural, social and economic changes underpin these drivers. In Australia, the displacement of Indigenous peoples and their nuanced and purposeful use of fire has been linked with extinctions of mammals and is transforming vegetation.

We need bolder conservation strategies

A suite of emerging actions — some established but receiving increasing attention, others new — could help us navigate this new fire era and save species from extinction. They include:

In Africa, reintroducing grazing animals such as rhinoceros create patchy fire regimes.
Sally Archibald, Author provided

Where to from here?

The input of scientists will be valuable in helping navigate big decisions about new and changing ecosystems.

Empirical data and models can monitor and forecast changes in biodiversity. For example, new modelling has allowed University of Melbourne researchers to identify alternative strategies for introducing planned or prescribed burning that reduces the risk of large bushfires to koalas.

New partnerships are also needed to meet the challenges ahead.

At the local and regional scale, Indigenous-led fire stewardship is an important approach for fostering relationships between Indigenous and non-Indigenous organisations and communities around the world.

Frank Lake, a co-author on our new paper, works with Yurok and Karuk fire practitioners, shown here burning under oaks.
Frank Lake, U.S Department of Agriculture Forest Service Pacific Southwest Research Station.

And international efforts to reduce greenhouse gas emissions and limit global warming are crucial to reduce the risk of extreme fire events. With more extreme fire events ahead of us, learning to understand and adapt to changes in fire regimes has never been more important.




Read more:
The world’s best fire management system is in northern Australia, and it’s led by Indigenous land managers


The Conversation


Luke Kelly, Senior Lecturer in Ecology and Centenary Research Fellow, University of Melbourne; Annabel Smith, Lecturer in Wildlife Management, The University of Queensland; Katherine Giljohann, Postdoctoral research fellow, University of Melbourne, and Michael Clarke, Professor of Zoology, La Trobe University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The buffel kerfuffle: how one species quietly destroys native wildlife and cultural sites in arid Australia



Buffel grass surrounding Hakea divaricata, a bushfood and medicine tree.
Ellen Ryan-Colton, Author provided

Christine Schlesinger, Charles Darwin University; Ellen Ryan-Colton, Charles Darwin University; Jennifer Firn, Queensland University of Technology, and John Read

Many of us are aware of the enormous destruction feral cats inflict on Australia’s native wildlife, but there’s another introduced species that will cause at least as much harm if left unmanaged — yet it receives far less attention.

We’re referring to buffel grass (Cenchrus ciliaris), a plant native to parts of Africa and Asia that has been widely introduced elsewhere for pasture and to stabilise soils.




Read more:
One cat, one year, 110 native animals: lock up your pet, it’s a killing machine


Buffel is fast growing, deep rooted and easy to establish, with each plant producing thousands of seeds. But these very characteristics for which it was prized have caused it to spread much further than ever planned.

We recently published two studies on buffel grass. One looked at just how serious the buffel invasion is to humans and wildlife by comparing it to other high-profile threats such as cats and foxes. The other study found that when buffel was removed, native wildlife quickly bounced back.

A catastrophic threat to wildlife

Buffel is now one of the worst invaders of dryland ecosystems worldwide. In Australia, this single species has replaced once diverse communities of native grasses and wildflowers across vast tracks of land. For example, most conservation reserves in the southern part of the NT have been invaded, including parts of Uluru-Kata Tjuta National Park.

Because it grows so thickly, the dense grassy fuel can feed bigger, hotter and sometimes unexpected fires. These new fires are a risk to wildlife, humans and large, old trees.

Buffel and fire affected shrubs starting to burn
Buffel grass promotes new fire risks.
Jennifer Firn, Author provided

Our study compared buffel to threats posed by changed fire regimes, feral predators (cats and foxes) and feral herbivores (rabbits and camels). We found buffel was equal to feral cats and foxes in terms of future risk to biodiversity.

Feral cats are currently listed as threatening some 139 species under national environment legislation, including the night parrot and the central rock rat. Each year across Australia, feral cats kill more than three billion animals.




Read more:
Feed or weed? New pastures are sowing problems for the future


Buffel is formally listed as threatening 27 species under this legislation, such as the floodplain skink (buffel can choke its burrows). But because there has been much less research on the impacts of buffel, this number is likely a significant underestimate.

Unlike cats, buffel impacts whole plant communities and the animals they support. For example, when large old trees are burnt, birds that rely on tree hollows for nesting can no longer breed successfully.

Buffel grass surrounds bushfood wattleseed.
Buffel grass surrounding wattleseed, a bushfood.
Ellen Ryan-Colton, Author provided

What’s more, buffel has only spread widely in the last 20-30 years, which means its full impact on ecosystems has not yet been realised. In fact, 70% of the Australian continent has suitable conditions for buffel growth and could, in time, become invaded.

In contrast, cats have already roamed Australia for more than 200 years and, tragically, have caused many species, like the lesser stick-nest rat, to become extinct.

A social and cultural threat for Aboriginal people

Our study found buffel ranked higher than any other environmental threat in terms of its social and cultural impacts for Aboriginal people.

Because buffel is valued as a pasture grass in some regions, much debate has focused on its agro‐economic benefits versus environmental costs.

Meanwhile, the views and values of Aboriginal custodians of inland Australia have remained marginalised. It’s time this changes.

Nyanyu Watson showing how it’s harder to see animal tracks in areas occupied by buffel grass.
Ellen Ryan-Colton, Author provided

While feral cats and buffel both threaten culturally important wildlife, buffel is also causing the decline of valued plant foods and medicines.

For example, native desert raisin (Solanum centrale) — “katjirra” to Western Arrernte people and “kampuṟarpa” to Pitjantjatjara people — remains an important staple food across central Australia and is part of Australia’s living cultural heritage.

However, it is becoming harder for women to find and collect as buffel takes over country.

Buffel grass growing right under desert fig
Buffel grass growing right under desert fig, a bushfood that’s sensitive to fire.
Ellen Ryan-Colton, Author provided

Buffel also damages important cultural sites by bringing fire and choking water holes. Thick grass makes it difficult to walk through country and it’s now hard to see tracks or animals.

Together with the loss of species, this inhibits the transfer of cultural knowledge from one generation to another.

The return of native wildlife

Buffel responds well to herbicide in smaller areas, and spread can be slowed or stopped by treating isolated infestations.

For six years, we tracked the response of native plants and animals (particularly lizards) after buffel was treated at six sites in the Tjoritja National Park near Alice Springs. And we found biodiversity soon bounced back.

A buffel grass removal experiment, near Alice Springs.
Christine Schlesinger, Author provided

Following good rains, native plants like billy buttons and golden everlastings that had just been hanging on quickly re-established in areas where buffel was treated. And as native plant communities were restored, a range of lizards and other wildlife returned, too.

Birds such as Australian ring-neck parrots and red-tailed black-cockatoos began to selectively use the treated areas, foraging on seeds on the more open ground.

Ants also became much more abundant and diverse where buffel was removed. Ants play an important role in ecosystems, for example, by dispersing seeds. This has likely been diminished in buffel-occupied areas.

Fire-tailed skink
A fire-tailed skink at one of the the buffel removal sites.
Christine Schlesinger, Author provided

Importantly, while research demonstrates the potential for ecosystem recovery following effective control, the negative effects of buffel on fauna increased in areas where we did nothing.

Where to from here?

The findings from both our studies underline the urgent need for management on a much larger scale than what is currently possible, and prevention of further spread.

It’s clear a nationally coordinated response is required, along with policies that support positive local initiatives.

Creating and maintaining large buffel-free sanctuaries in areas not yet invaded could help to protect biodiversity in the future. But we found the cost of maintaining these could be an estimated 40–50 times more than other pest-free sanctuaries, if restricted to current methods of control.




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Pulling out weeds is the best thing you can do to help nature recover from the fires


This is why Australia needs new, cost-effective, culturally appropriate and safe control options, rolled out on a broad scale. We stress the need for Aboriginal people from regions affected by buffel and prone to invasion to be central to discussions and the development of solutions.

It’s also important to note controlling buffel doesn’t require its eradication from pastoral regions where it’s valued. It does, however, require a national commitment and dedicated research, with strategic, coordinated and committed action.The Conversation

Christine Schlesinger, Senior Lecturer in Environmental Science and Ecology, Charles Darwin University; Ellen Ryan-Colton, PhD candidate, Charles Darwin University; Jennifer Firn, Professor, Queensland University of Technology, and John Read, Associate Lecturer, Ecology and Environmental Sciences

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Discovering New Flowering Plants Species While Bushwalking in Australia


The link below is to an article that looks at discovering new flowering plant species while bushwalking in Australia.

For more visit:
https://www.lifehacker.com.au/2020/09/find-new-species-of-daisies-on-your-aussie-bushwalks/

‘Compassionate conservation’: just because we love invasive animals, doesn’t mean we should protect them



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Kaya Klop-Toker, University of Newcastle; Alex Callen, University of Newcastle; Andrea Griffin, University of Newcastle; Matt Hayward, University of Newcastle, and Robert Scanlon, University of Newcastle

On an island off the Queensland coast, a battle is brewing over the fate of a small population of goats.

The battle positions the views of some conservation scientists and managers who believe native species must be protected from this invasive fauna, against those of community members who want to protect the goat herd to which they feel emotionally connected. Similar battles colour the management decisions around brumbies in Kosciuszko National Park and cats all over Australia.




Read more:
National parks are for native wildlife, not feral horses: federal court


These debates show the impact of a new movement called “compassionate conservation”. This movement aims to increase levels of compassion and empathy in the management process, finding conservation solutions that minimise harm to wildlife. Among their ideas, compassionate conservationists argue no animal should be killed in the name of conservation.

But preventing extinctions and protecting biodiversity is unlikely when emotion, rather than evidence, influence decisions. As our recent paper argues, the human experience of compassion and empathy is fraught with inherent biases. This makes these emotions a poor compass for deciding what conservation action is right or wrong.

It sounds good on paper

We are facing a biological crisis unparalleled in human history, with at least 25% of the world’s assessed species at risk of extinction. These trends are particularly bad in Australia, where we have one of the world’s worst extinction records and the world’s highest rate of mammal extinctions.

The federal government recently announced it will commit to a new ten-year threatened species strategy, focused on eradicating feral pests such as foxes and cats.




Read more:
One cat, one year, 110 native animals: lock up your pet, it’s a killing machine


This approach goes against the principles underpinning compassionate conservation. The movement, which first emerged in 2010, is founded on the ideals of “first do no harm” and “individuals matter”.

When you first think about it, this idea sounds great. Why kill some animals to save others?

Well, invasive animals — those either intentionally or accidentally moved to a new location — are one of the biggest threats to global biodiversity.

Invasive predators, such as cats and foxes, have caused the extinction of 142 vertebrate species worldwide. In Australia, feral and domestic cats kill more than 15 billion native animals per year.

Fortunately, endangered populations can recover when these pests are removed. Controlling pest numbers is one of the most effective tools available to conservationists.

Conflicting moral standpoints

Killing pests is at stark odds with the “do no harm” values promoted by the compassionate conservation movement.

Thousands of wild horses are rapidly degrading the ecosystems of Australia’s high country.

Compassionate conservationists argue it’s morally wrong to kill animals for management, whereas conservation scientists argue it’s morally wrong to allow species to go extinct — especially if human actions (such as the movement of species to new locations) threaten extinction.

These conflicting moral standpoints result in an emotional debate about when it is justified to kill or let be killed. This argument centres on emotion and moral beliefs. There is no clear right or wrong answer and, therefore, no resolution.

In an attempt to break this emotional stalemate, we explored the biases inherent in the emotions of compassion and empathy, and questioned if increased empathy and compassion are really what conservation needs.

Evolutionary biases

At first, compassion and empathy may appear vital to conservation, and on an individual level, they probably are. People choose to work in conservation because they care for wild species. But compassion and empathy come with strong evolutionary biases.

The first bias is that people feel more empathy toward the familiar — people care more for things they relate most closely to. The second bias is failure to scale-up — we don’t feel 100 times more sorrow when hearing about 100 people dying, compared to a single person (or species).

Evolution has shaped our emotions to peak for things we relate most strongly to, and to taper off when numbers get high — most likely to protect us from becoming emotionally overloaded.

Let’s put these emotions in the context of animal management. Decisions based on empathy and compassion will undoubtedly favour charismatic, relatable species over thousands of less-familiar small, imperilled creatures.

This bias is evident in the battle over feral horses in national parks. There is public backlash over the culling of brumbies, yet there is no such response to the removal of feral pigs, despite both species having similarly negative impacts on protected habitats.

More harm than good

If compassionate conservation is adopted, culling invasive species would cease, leading to the rapid extinction of more vulnerable native species. A contentious example is the race to save the endangered Tristan albatross from introduced mice on Gough Island in the south Atlantic.

Sealers introduced mice in the 1800s, and the mice have adapted to feed on albatross chicks, killing an estimated two million birds per year. Under compassionate conservation, lethal control of the mice would not be allowed, and the albatross would be added to the extinction list within 20 years.




Read more:
Invasive species are Australia’s number-one extinction threat


What’s more, compassionate conservation advocates for a more hands-off approach to remove any harm or stress to animals. This means even the management of threatened fauna would be restricted.

Under this idea, almost all current major conservation actions would not be allowed because of temporary stress placed on individual animals. This includes translocations (moving species to safer habitat), captive breeding, zoos, radio tracking and conservation fencing.

With 15% of the world’s threatened species protected in zoos and undergoing captive breeding, a world with compassionate conservation would be one with far fewer species, and we argue, much less conservation and compassion.

In this time of biodiversity crisis and potential ecosystem collapse, we cannot afford to let emotion bias our rationale. Yes, compassion and empathy should drive people to call for more action from their leaders to protect biodiversity. But what action needs to be taken should be left to science and not our emotions.




Read more:
Don’t blame cats for destroying wildlife – shaky logic is leading to moral panic


The Conversation


Kaya Klop-Toker, Conservation Biology Researcher, University of Newcastle; Alex Callen, Post-doctoral researcher, University of Newcastle; Andrea Griffin, Senior Lecturer, School of Psychology, University of Newcastle; Matt Hayward, Associate professor, University of Newcastle, and Robert Scanlon, PhD Candidate in Restoration Ecology, University of Newcastle

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How a scientific spat over how to name species turned into a big plus for nature



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Stephen Garnett, Charles Darwin University; Les Christidis, Southern Cross University; Richard L. Pyle, University of Hawaii, and Scott Thomson, Universidade de São Paulo

Taxonomy, or the naming of species, is the foundation of modern biology. It might sound like a fairly straightforward exercise, but in fact it’s complicated and often controversial.

Why? Because there’s no one agreed list of all the world’s species. Competing lists exist for organisms such as mammals and birds, while other less well-known groups have none. And there are more than 30 definitions of what constitutes a species. This can make life difficult for biodiversity researchers and those working in areas such as conservation, biosecurity and regulation of the wildlife trade.

In the past few years, a public debate erupted among global taxonomists, including those who authored and contributed to this article, about whether the rules of taxonomy should be changed. Strongly worded ripostes were exchanged. A comparison to Stalin was floated.

But eventually, we all came together to resolve the dispute amicably. In a paper published this month, we proposed a new set of principles to guide what one day, we hope, will be a single authoritative list of the world’s species. This would help manage and conserve them for future generations.

In the process, we’ve shown how a scientific stoush can be overcome when those involved try to find common ground.

Baby crocodile emerging from egg.
Scientists worked out a few differences over how to name species.
Laurent Gillieron/EPA

How it all began

In May 2017 two of the authors, Stephen Garnett and Les Christidis, published an article in Nature. They argued taxonomy needed rules around what should be called a species, because currently there are none. They wrote:

for a discipline aiming to impose order on the natural world, taxonomy (the classification of complex organisms) is remarkably anarchic […] There is reasonable agreement among taxonomists that a species should represent a distinct evolutionary lineage. But there is none about how a lineage should be defined.

‘Species’ are often created or dismissed arbitrarily, according to the individual taxonomist’s adherence to one of at least 30 definitions. Crucially, there is no global oversight of taxonomic decisions — researchers can ‘split or lump’ species with no consideration of the consequences.

Garnett and Christidis proposed that any changes to the taxonomy of complex organisms be overseen by the highest body in the global governance of biology, the International Union of Biological Sciences (IUBS), which would “restrict […] freedom of taxonomic action.”




Read more:
Taxonomy, the science of naming things, is under threat


An animated response

Garnett and Christidis’ article raised hackles in some corners of the taxonomy world – including coauthors of this article.

These critics rejected the description of taxonomy as “anarchic”. In fact, they argued there are detailed rules around the naming of species administered by groups such as the International Commission on Zoological Nomenclature and the International Code of Nomenclature for algae, fungi, and plants. For 125 years, the codes have been almost universally adopted by scientists.

So in March 2018, 183 researchers – led by Scott Thomson and Richard Pyle – wrote an animated response to the Nature article, published in PLoS Biology.

They wrote that Garnett and Christidis’ IUBS proposal was “flawed in terms of scientific integrity […] but is also untenable in practice”. They argued:

Through taxonomic research, our understanding of biodiversity and classifications of living organisms will continue to progress. Any system that restricts such progress runs counter to basic scientific principles, which rely on peer review and subsequent acceptance or rejection by the community, rather than third-party regulation.

In a separate paper, another group of taxonomists accused Garnett and Christidis of trying to suppress freedom of scientific thought, likening them to Stalin’s science advisor Trofim Lysenko.

Sea sponge under a microscope
Taxonomy can influence how conservation funding is allocated.
Queensland Museum

Finding common ground

This might have been the end of it. But the editor at PLoS Biology, Roli Roberts, wanted to turn consternation into constructive debate, and invited a response from Garnett and Christidis. In the to and fro of articles, we all found common ground.

We recognised the powerful need for a global list of species – representing a consensus view of the world’s taxonomists at a particular time.




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Such lists do exist. The Catalogue of Life, for example, has done a remarkable job in assembling lists of almost all the world’s species. But there are no rules on how to choose between competing lists of validly named species. What was needed, we agreed, was principles governing what can be included on lists.

As it stands now, anyone can name a species, or decide which to recognise as valid and which not. This creates chaos. It means international agreements on biodiversity conservation, such as the Convention on International Trade in Endangered Species (CITES) and the Convention on the Conservation of Migratory Species of Wild Animals (CMS), take different taxonomic approaches to species they aim to protect.

We decided to work together. With funding from the IUBS, we held a workshop in February this year at Charles Darwin University to determine principles for devising a single, agreed global list of species.

Pengiuns embracing each other.
The sparring scientists came together to develop agreed principles.
Shutterstock

Participants came from around the world. They included taxonomists, science governance experts, science philosophers, administrators of the nomenclatural (naming) codes, and taxonomic users such as the creators of national species lists.

The result is a draft set of ten principles that to us, represent the ideals of global science governance. They include that:

  • the species list be based on science and free from “non-taxonomic” interference
  • all decisions about composition of the list be transparent
  • governance of the list aim for community support and use
  • the listing process encompasses global diversity while accommodating local knowledge.

The principles will now be discussed at international workshops of taxonomists and the users of taxonomy. We’ve also formed a working group to discuss how a global list might come together and the type of institution needed to look after it.

We hope by 2030, a scientific debate that began with claims of anarchy might lead to a clear governance system – and finally, the world’s first endorsed global list of species.


The following people provided editorial comment for this article: Aaron M Lien, Frank Zachos, John Buckeridge, Kevin Thiele, Svetlana Nikolaeva, Zhi-Qiang Zhang, Donald Hobern, Olaf Banki, Peter Paul van Dijk, Saroj Kanta Barik and Stijn Conix.

The Conversation

Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University; Les Christidis, Professor, Southern Cross University; Richard L. Pyle, Associate lecturer, University of Hawaii, and Scott Thomson, Research associate, Universidade de São Paulo

This article is republished from The Conversation under a Creative Commons license. Read the original article.

I travelled Australia looking for peacock spiders, and collected 7 new species (and named one after the starry night sky)



Heath Warwick, Author provided

Joseph Schubert, Museums Victoria

After I found my first peacock spider in the wild in 2016, I was hooked. Three years later, I was travelling across Australia on a month-long expedition to document and name new species of peacock spiders.

Peacock spiders are a unique group of tiny, colourful, dancing spiders native to Australia. They’re roughly between 2.5 and 6 millimetres, depending on the species. Adult male peacock spiders are usually colourful, while female and juvenile peacock spiders are usually dull brown or grey.




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The spectacular peacock spider dance and its strange evolutionary roots


Like peacocks, the mature male peacock spiders display their vibrant colours in elegant courtship displays to impress females. They often elevate and wave their third pair of legs and lift their brilliantly coloured abdomens – like dancing.

Maratus laurenae. Male peacock spiders have brilliant colours on their abdomen to attract females.
Author provided

Up until 2011, there were only seven known species of them. But since then, the rate of scientific discovery has skyrocketed with upwards of 80 species being discovered in the last decade.

Thanks to my trip across Australia and the help from citizen scientists, I’ve recently scientifically described and named seven more species from Western Australia, South Australia and Victoria. This brings the total number of peacock spider species known to science up to 86.

Spider hunting: a game of luck

Citizen scientists – other peacock spider enthusiasts – shared photographs and locations of potentially undocumented species with me. I pulled these together to create a list of places in Australia to visit.

I usually find spider hunting to be a relaxing pastime, but this trip was incredibly stressful (albeit amazing).

The thing about peacock spiders is they’re mainly active during spring, which is when they breed. Colourful adult males are difficult – if not impossible – to find at other times of year, as they usually die shortly after the mating season. This meant I had a very short window to find what I needed to, or I had to wait another year.

Classic.

Even when they’re active, they can be difficult to come across unless weather conditions are ideal. Not too cold. Not too rainy. Not too hot. Not too sunny. Not too shady. Not too windy. As you can imagine, it’s largely a game of luck.

The wild west

I arrived in Perth, picked up my hire car and bought a foam mattress that fitted in the back of my car – my bed for half of the trip. I stocked up on tinned food, bread and water, and I headed north in search of these tiny eight-legged gems.

My first destination: Jurien Bay. I spent the whole day under the hot sun searching for a peculiar, scientifically unknown species that Western Australian photographer Su RamMohan had sent me photographs of. I was in the exact spot it had been photographed, but I just couldn’t find it!

I travelled across Denmark, Western Australia.
Author provided

The sun began to lower and I was using up precious time. I made what I now believe was the right decision and abandoned the Jurien Bay species for another time.

I spent days travelling between dramatic coastal landscapes, the rugged inland outback, and old, mysterious woodlands.

Kalbarri Gorge, Western Australia, where Maratus constellatus was found.
Author provided

I hunted tirelessly with my eyes fixed on the ground searching for movement. In a massive change of luck from the beginning of my trip, it seemed conditions were (mostly) on my side.

With the much-appreciated help of some of my field companions from the University of Hamburg and volunteers from the public, a total of five new species were discovered and scientifically named from Western Australia.

The Little Desert

Two days after returning from Western Australia, I headed to the Little Desert National Park in Victoria on a Bush Blitz expedition, joined by several of my colleagues from Museums Victoria.

I’d thought the landscape’s harsh, dry conditions were unsuitable for peacock spiders, as most described species are known to live in temperate regions.

Capturing spiders in a bug net.
Heath Warwick, Author provided

To my surprise, we found a massive diversity of them, including two species with a bigger range than we thought, and the discovery of another species unknown to science.

This is the first time two known species – Maratus robinsoni and Maratus vultus – had been found in Victoria. Previously, they had only been known to live in eastern New South Wales and southern Western Australia respectively.




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Our findings suggest other known species may have much bigger geographic ranges than we previously thought, and may occur in a much larger variety of habitats.

And our discovery of the unknown species (Maratus inaquosus), along with another collected by another wildlife photographer Nick Volpe from South Australia (Maratus volpei) brought the tally of discoveries to seven.

What’s in a name?

Writing scientific descriptions, documenting, and naming species is a crucial part in conserving our wildlife.




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Spiders are a treasure trove of scientific wonder


With global extinction rates at an unprecedented high, species conservation is more important than ever. But the only way we can know if we’re losing species is to show and understand they exist in the first place.


  • Maratus azureus: “Deep blue” in Latin, referring to the colour of the male.
Maratus azureus.
Author provided
  • Maratus constellatus: “Starry” in Latin, referring to the markings on the male’s abdomen which look like a starry night sky.
Maratus constellatus.
Author provided
  • Maratus inaquosus: “Dry” or “arid” in Latin, for the dry landscape in Little Desert National Park this species was found in.
Maratus inaquosus
Author provided
  • Maratus laurenae: Named in honour of my partner, Lauren Marcianti, who has supported my research with enthusiasm over the past few years.
Maratus laurenae
Author provided
  • Maratus noggerup: Named after the location where this species was found: Noggerup, Western Australia.
Maratus noggerup
Author provided
  • Maratus suae: Named in honour of photographer Su RamMohan who discovered this species and provided useful information about their locations in Western Australia.
Maratus suae
Author provided
  • Maratus volpei: Named in honour of photographer Nick Volpe who discovered and collected specimens of this species to be examined in my paper.
Maratus volpei
Nick Volpe, Author provided

These names allow us to communicate important information about these animals to other scientists, as well as to build legislation around them in the case there are risks to their conservation status.

I plan on visiting some more remote parts of Australia in hopes of finding more new peacock spider species. I strongly suspect there’s more work to be done, and more peacock spiders to discover.The Conversation

Joseph Schubert, Entomology/Arachnology Registration Officer, Museums Victoria

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We’ve just discovered two new shark species – but they may already be threatened by fishing



One of the newly discovered sixgilled sawshark species (Pliotrema kajae).
Simon Weigmann, Author provided

Per Berggren, Newcastle University and Andrew Temple, Newcastle University

Finding a species that’s entirely new to science is always exciting, and so we were delighted to be a part of the discovery of two new sixgill sawsharks (called Pliotrema kajae and Pliotrema annae) off the coast of East Africa.

We know very little about sawsharks. Until now, only one sixgill species (Pliotrema warreni) was recognised. But we know sawsharks are carnivores, living on a diet of fish, crustaceans and squid. They use their serrated snouts to kill their prey and, with quick side-to-side slashes, break them up into bite-sized chunks.

The serrated snout of a sixgill sawshark (Pliotrema annae).
Ellen Barrowclift-Mahon/Marine MEGAfauna Lab/Newcastle University., Author provided

Sawsharks look similar to sawfish (which are actually rays), but they are much smaller. Sawsharks grow to around 1.5 metres in length, compared to 7 metres for a sawfish and they also have barbels (fish “whiskers”), which sawfish lack. Sawsharks have gills on the side of their heads, whereas sawfish have them on the underside of their bodies.

A sixgill sawshark (Pliotrema annae) turned on its side, showing gills and barbels.
Ellen Barrowclift-Mahon, Author provided

Together with our colleagues, we discovered these two new sawsharks while researching small-scale fisheries that were operating off the coasts of Madagascar and Zanzibar. While the discovery of these extraordinary and interesting sharks is a wonder in itself, it also highlights how much is still unknown about biodiversity in coastal waters around the world, and how vulnerable it may be to poorly monitored and managed fisheries.

The three known species of sixgill sawshark. The two new species flank the original known species. From left to right: Pliotrema kajae, Pliotrema warreni (juvenile female) and Pliotrema annae (presumed adult female).
Simon Weigmann, Author provided

Fishing in the dark

Despite what their name might suggest, small-scale fisheries employ around 95% of the world’s fishers and are an incredibly important source of food and money, particularly in tropical developing countries. These fisheries usually operate close to the coast in some of the world’s most important biodiversity hotspots, such as coral reefs, mangrove forests and seagrass beds.

For most small-scale fisheries, there is very little information available about their fishing effort – that is, how many fishers there are, and where, when and how they fish, as well as exactly what they catch. Without this, it’s very difficult for governments to develop management programmes that can ensure sustainable fishing and protect the ecosystems and livelihoods of the fishers and the communities that depend on them.

Small-scale fishers of Zanzibar attending their driftnets.
Per Berggren/Marine MEGAfauna Lab/Newcastle University, Author provided

While the small-scale fisheries of East Africa and the nearby islands are not well documented, we do know that there are at least half a million small-scale fishers using upwards of 150,000 boats. That’s a lot of fishing. While each fisher and boat may not catch that many fish each day, with so many operating, it really starts to add up. Many use nets – either driftnets floating at the surface or gillnets, which are anchored close to the sea floor. Both are cheap but not very selective with what they catch. Some use longlines, which are effective at catching big fish, including sharks and rays.




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In 2019, our team reported that catch records were massively underreporting the number of sharks and rays caught in East Africa and the nearby islands. With the discovery of two new species here – a global hotspot for shark and ray biodiversity – the need to properly assess the impact of small-scale fisheries on marine life is even more urgent.

Pliotrema kajae, as it might look swimming in the subtropical waters of the western Indian Ocean.
Simon Weigmann, Author provided

How many other unidentified sharks and other species are commonly caught in these fisheries? There is a real risk of species going extinct before they’re even discovered.

Efforts to monitor and manage fisheries in this region, and globally, must be expanded to prevent biodiversity loss and to develop sustainable fisheries. There are simple methods available that can work on small boats where monitoring is currently absent, including using cameras to document what’s caught.

A selection of landed fish – including sharks, tuna and swordfish.
Per Berggren, Author provided

The discovery of two new sixgill sawsharks also demonstrates the value of scientists working with local communities. Without the participation of fishers we may never have found these animals. From simple assessments all the way through to developing methods to alter catches and manage fisheries, it’s our goal to make fisheries sustainable and preserve the long-term future of species like these sawsharks, the ecosystems they live in and the communities that rely on them for generations to come.The Conversation

Per Berggren, Marine MEGAfauna Lab, Newcastle University and Andrew Temple, Postdoctoral Research Associate in Marine Biology, Newcastle University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

When introduced species are cute and loveable, culling them is a tricky proposition



Shutterstock

Lily van Eeden, University of Sydney; Chris Dickman, University of Sydney; Jeremy T. Bruskotter, The Ohio State University; Mathew Crowther, University of Sydney, and Thomas Newsome, University of Sydney

Almost one in five Australians think introduced horses and foxes are native to Australia, and others don’t want “cute” or “charismatic” animals culled, even when they damage the environment. So what are the implications of these attitudes as we help nature recover from bushfires?

Public opposition to culling programs is often at odds with scientists and conservationists.

These tensions came to the fore last month when scientists renewed calls for a horse-culling program to protect native species in Kosciusko National Park – a move strongly opposed by some members of the public.

To manage the environment effectively, including after bushfires, we need to understand the diversity of opinion on what constitutes a native animal, and recognise how these attitudes can change.

Governments are responding

In Australia, native species are usually defined as those present before European settlement in 1788. Lethal pest control usually targets species introduced after this time, such as horses, foxes, deer, rabbits, pigs, and cats.

But fire makes native fauna more vulnerable to introduced predators. Fire removes ground layer vegetation that small wildlife would use as protective cover. When this cover is gone, these animals are easier targets for predators like cats and foxes.




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State governments have started to respond to this impending crisis. In January, the New South Wales government announced its largest ever program to control feral predators, in an effort to protect native fauna after the fires.

The plan includes 1500-2000 hours of aerial and ground shooting of deer, pigs, and goats and distributing up to a million poison baits targeting foxes, cats, and dingoes over 12 months.

Similarly, the Victorian government announced a A$17.5 million program to protect biodiversity the fires affected, including A$7 million for intensified management of threats like introduced animals.

But will the public be on board? Widespread media coverage of the recent fires and their impacts on wildlife, including the loss of more than a billion animals, might garner support for protecting native wildlife from pests.

On the other hand, efforts to manage animals such as cats and horses might be hampered by a lack of public support for culling charismatic animals that many people value or view as belonging in Australia now.

Different folks, different strokes

The distinctions many Australians draw – native animals are “good” and introduced species are “bad” – shape how people view conservation efforts. A survey we conducted in 2017 found people more likely to disapprove of lethal methods for managing species they perceived to be native.

In the same survey, we found nearly one in five Australians considered horses and foxes to be native to Australia.

This suggests either that a) people lack knowledge of Australia’s natural history or b) people disagree with conservationists’ definition of animal “nativeness”.

Calls to manage horses to prevent environmental degradation in Australian national parks are hugely controversial, with many people arguing the horses belong now.
Shutterstock

Many introduced species, such as horses and foxes, have existed in Australia for more than a century and have established populations across much of the country. It’s unlikely they’ll ever be eradicated.

Some people, including scientists, say we should just accept introduced species as part of Australia’s fauna. They argue current management justifies killing based on moral, not scientific judgements and introduced animals may increase biodiversity.




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But the issue remains extremely divisive. A central tenet of traditional conservation is that humans have a duty to protect native species and ecosystems from the threat introduced species pose. It’s difficult to do this without culling introduced animals.

Animal welfare concerns may also drive opposition to culling, taking the view that all animals, even non-natives, have intrinsic value and the right to live.

What’s more, non-native culling programs can be controversial when the animal is considered “cute” or “charismatic”, or of cultural value. For example, a plan to cull feral horses in the Kosciusko National Park in 2018 was met with public outrage, prompting the NSW government to overturn the decision.

Yet protecting introduced species in national parks goes against the very reason they were created – to conserve native ecosystems and species.

Some animals are more equal than others

When analysing public attitudes towards various species, we must also consider how attitudes shift over time.

In Australia, non-native animals such as domestic camels and donkeys were considered useful for transport and highly valued. But we ultimately turned them loose and relabelled them as pests when we started using cars.

We asked the Australian public whether they viewed dingoes, horses, and foxes as native or non-native in Australia.
van Eeden et al. (2020)

Interestingly, we’ve already accepted some introduced species as native. Humans brought dingoes to Australia at least 3,500 years ago. They’re described as native under Australian biodiversity legislation, and 85% of our 2017 survey participants considered dingoes to be native.

Perhaps its only a matter of time until more recently arrived species like horses and foxes are counted as native. Some scientists argue this shift should be based on how ecosystems and species adapt to these new arrivals. For example, some small Australian mammals show fear of dingoes or dogs, but they haven’t yet learnt to fear cats.

Native species can be pests too

Native species, such as kangaroos and possums, may also be culled if they’re perceived to be overabundant or damaging economic interests like agriculture.




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While the plight of bushfire-affected koalas on Kangaroo Island attracted considerable media interest, and the immediate welfare of any animal affected by fires is always a concern, koalas were actually introduced there.

They’ve been managed as a pest on Kangaroo Island for more than 20 years, and it’s unlikely the rescued koalas will be returned to the island. In this case, public concern transcends the distinction between native and introduced.

Public perception is important

We might never all agree on how best to manage native and non-native species. But effective environmental management, including after bushfires, requires understanding the diversity of opinion.

Doing so can help to develop management plans the public supports and allow effective communication about management that is controversial.

In fact, the NSW Office of Environment and Heritage did undertake an extensive public consultation process in developing their horse management plan for Kosciuszko National Park, but it wasn’t used after the “brumby bill” gave horses protection in 2018.




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With human lives and many animal lives lost, response to the bushfires is already highly emotive. Failure to consider public attitudes towards managing animals will lead to backlash, wasted money and time, and continuing decline of the native species whose conservation is the goal of these actions.The Conversation

Lily van Eeden, PhD Candidate in Human-Wildlife Conflict, University of Sydney; Chris Dickman, Professor in Terrestrial Ecology, University of Sydney; Jeremy T. Bruskotter, Professor, School of Environment and Natural Resources, The Ohio State University; Mathew Crowther, Associate professor, University of Sydney, and Thomas Newsome, Lecturer, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Fire almost wiped out rare species in the Australian Alps. Feral horses are finishing the job



Feral horses are destroying what little threatened species habitat was spared from bushfire.
Invasive Species Council

Jamie Pittock, Australian National University

On Friday I flew in a helicopter over the fire-ravaged Kosciuszko National Park. I was devastated by what I saw. Cherished wildlife species are at grave risk of extinction: those populations the bushfires haven’t already wiped out are threatened by thousands of feral horses trampling the land.

The New South Wales park occupies the highest mountain range in Australia and is home to plants and animals found nowhere else in the world. Many of these species are threatened, and their survival depends on protecting habitat as best we can.




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Double trouble as feral horse numbers gallop past 25,000 in the Australian Alps


Kosciuszko National Park provides habitat for two species of corroboree frog (critically endangered), the alpine she-oak skink (endangered), broad-toothed rat (vulnerable) and stocky galaxias (a critically endangered native fish), among other threatened species.

As the climate has warmed, the cool mountain habitat of these species is shrinking; bushfires have decimated a lot of what was left. Feral horses now threaten to destroy the remainder, and an urgent culling program is needed.

Devastation as far as the eye can see on the burnt western face of Kosciuszko National Park.
Jamie Pittock

Not a green leaf in sight

Australia’s plants and ecosystems did not evolve to withstand trampling by hard-hooved animals, or their intensive grazing. Unfortunately, the New South Wales government has allowed the population of feral horses in the park to grow exponentially in recent years to around 20,000.

I flew over the northern part of the park with members of the Invasive Species Council, who were conducting an urgent inspection of the damage. Thousands of hectares were completely incinerated by bushfires: not a green leaf was visible over vast areas. A cataclysm has befallen the western face of the mountains and tablelands around Kiandra and Mount Selwyn.




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Further north and east of Kiandra the fires were less intense and burnt patchily. On Nungar Plain the grassland and peat wetlands were only lightly burnt, and the first green shoots were already visible along the wetlands of the valley floor.

At first, I wondered if the fires may have spared two animals which live in tunnels in the vegetation on the sub-alpine high plains: the alpine she-oak skink and broad-toothed rat (which, despite the name is a cute, hamster-like creature).

The hamster-like broad toothed rat.
Flickr

But not only was their understory habitat burnt, a dozen feral horses were trampling the peat wetlands and eating the first regrowth.

On the unburnt or partially burnt plains a few ridges over, 100 or more horses were mowing down the surviving vegetation.

Precarious wildlife refuges

Next we flew over a small stream that holds the last remaining population of a native fish species, the stocky galaxias. A small waterfall is all that divides the species from the stream below, and the jaws of the exotic trout which live there.

The aftermath of the fires means the last refuge of the stocky galaxias is likely to become even more degraded.

Over the years, feral horses have carved terraces of trails into the land causing erosion and muddying the stream bank. As more horses congregate on unburnt patches of vegetation after the fires, more eroded sediment will settle on the stream bed and fill the spaces between rocks where the fish shelter. Ash runoff entering the stream may clog the gills of the fish, potentially suffocating them.

An Alpine she-oak skink.
Renee Hartley



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Many key wetland habitats of the southern and northern corroboree frogs have also been burnt. These striking yellow and black frogs nest in wetland vegetation.

A corroboree frog.
Flickr

We hovered over a key wetland for the northern corroboree frog that had not been burnt, deep in the alpine forest. A group of feral horses stood in it. They had created muddy wallows, trampled vegetation and worn tracks that will drain the wetland if their numbers are not immediately controlled.

Horses out of control

Five years ago a survey reported about 6,000 feral horses roaming in Kosciuszko National Park. By 2019, the numbers had jumped to at least 20,000.

We saw no dead horses from the air. Unlike our native wildlife, most appear to have escaped the fires.




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Flying down the upper Murrumbidgee River’s Long Plain, I saw large numbers of feral horses gathered in yet more wetlands. Displaced by the fires to the south and west, they were already trampling the mossy and heathy wetlands that store and filter water in the headwaters.

The Murrumbidgee River is a key water source for south-east Australia. The horses stir up sediment and defecate in the water. They create channels which drain and dry the wetlands, exposing them to fire.

One-third of Kosciuszko National Park has been burnt out and at the time of writing the fires remain active. Feral horses are badly compounding the damage.

If we don’t immediately reduce feral horse numbers, the consequences for Kosciuszko National Park and its unique Australian flora and fauna will be horrendous.

Responsible managers limit the numbers of livestock on their lands and control feral animals. The NSW government must repeal its 2018 legislation protecting feral horses in Kosciuszko National Park, and undertake a responsible control program similar to those of the Australian Capital Territory and Victorian governments.

Without an emergency cull of feral horses in Kosciuszko National Park, burnt vegetation may not fully recover and threatened species will march further towards extinction.The Conversation

Jamie Pittock, Professor, Fenner School of Environment & Society, Australian National University

This article is republished from The Conversation under a Creative Commons license. Read the original article.