Here are 5 new species of Australian trapdoor spider. It took scientists a century to tell them apart


A female Euoplos variabilis from Mount Tamborine.
Jeremy Wilson

Mark Harvey, The University of Western AustraliaAfter a century of scientific confusion, we can now officially add five new species to Australia’s long list of trapdoor spiders — secretive, burrowing relatives of tarantulas.

It all started in 1918, when a species known as Euoplos variabilis, was first described. Since then, this species has been considered widespread throughout south-eastern Queensland.

However, in new research, fellow arachnologists from the Queensland Museum studied the physical appearance and DNA of these trapdoor spiders. They revealed this “widespread” species is actually several.

Many trapdoor spider species are short-range endemics, meaning they only occur in one small area. This makes them especially vulnerable to threats such as habitat destruction and degradation, which is why the discovery and description of these new species from Queensland is so important — they can now be protected from future threats.

Meet Australia’s trapdoor spiders

To many people, Australia’s spider diversity is a source of fear. To arachnologists like myself, it’s a goldmine.

Weird and wonderful new species are everywhere. While new discoveries are relatively common, it’s likely most Australian spider species are still yet to be named by science.

The crenate burrow of Euoplos crenatus, a recently discovered ‘palisade trapdoor spider’.
Michael Rix

Trapdoor spiders live in burrows that usually have a hinged door at the entrance that the spider constructs using silk, soil or other material from the surrounding area. Their burrows can be camouflaged, but to a trained eye they’re easily found on the soil embankments beside walking tracks in eastern Australian rainforests.

In the past few years, I’ve been part of a team studying the spiny trapdoor spiders — a group of relatively large (up to about seven centimetres long, including legs) but highly secretive spiders found throughout Australia. They belong to an ancient group called the Mygalomorphae that, alongside tarantulas, includes the infamous Australian funnel-web spiders.

Australian spiders of the group called the Mygalomorphae: left, a funnel-web spider; middle, a wishbone spider; right, a tree trapdoor spider.
Jeremy Wilson

Like other trapdoor spiders, adult male and female spiny trapdoor spiders look shockingly different. When males reach adulthood, their physical appearance changes: their legs get longer and thinner, and their first appendages (called “pedipalps”) develop into structures used for mating. In contrast, adult females remain short-legged and robust.

Male trapdoor spiders undergo this dramatic change because as adults they must leave their burrow and search for females to breed.

Their long legs presumably help them run faster and further in search of females, and also allow them to keep the vulnerable parts of their body out of harm’s way once they meet the (usually larger) female, who isn’t always happy to see them.

The mystery of the trapdoor spider from Mount Tamborine

This striking differences in appearance between male and female spiny trapdoor spiders (“sexual dimorphism”) was at the heart of the mystery regarding the true identity of Euoplos variabilis.

A male and female of the same species of trapdoor spider, showing the sleek, long-legged male and the robust female.
Jeremy Wilson

When the species was first described in 1918, it was based only on female spiders, which were red-brown, large and lived in the rainforest of Mount Tamborine, just south of Brisbane.

In 1985, a male spider, also from Mount Tamborine, was finally linked to the original females. Matching male and female trapdoor spiders of the same species can be difficult because they look so different.

This all changed when the Queensland Museum team began researching the spiny trapdoor spiders of eastern Australia in 2015. When they looked in the museum’s natural history collection, it seemed like males of the Mount Tamborine trapdoor spider were widespread, spanning Brisbane to the Sunshine Coast.




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But strangely, they found females from different locations looked different.

While females from the Mount Tamborine rainforest were large and red-brown, those from the lowlands of north Brisbane were small and tan. And in the rainforest of the D’Aguilar Range, north of Brisbane, the females were even bigger, with a bright orange carapace and red legs.

Could these really all be the same species?

One of the males originally thought to be Euoplos variabilis. It was later realised these males belong to an entirely different species, now called Cryptoforis hughesae.
Michael Rix

This mystery was solved in two steps

First, in 2018, the museum’s arachnologists discovered the seemingly widespread males were actually members of a completely different group of trapdoor spiders, which also occurs in eastern Australia. In other words, there had been a male/female mismatch!

Then, by collecting fresh trapdoor spiders around south-east Queensland and studying their DNA, they discovered the Mount Tamborine trapdoor spider actually doesn’t occur in Brisbane at all. In fact, it’s found only in the mountain ranges bordering New South Wales, with Mount Tamborine being its the most northerly location.

Surprisingly, the female spiders found in Brisbane, the D’Aguilar range, and in various other areas, turned out to be several completely different species, new to science.




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These species can be distinguished by subtle differences in size and colour, and by differences in their DNA. The different species seem to be adapted to different habitats, at different elevations.

So, alongside Euoplos variabilis, the original Mount Tamborine trapdoor spider, the new confirmed species are:

  • Euoplos raveni and Euoplos schmidti, both from the lowland forests of the Brisbane Valley, south of the Brisbane River
  • Euoplos regalis from the upland rainforest of the D’Aguilar Range
  • Euoplos jayneae from the the lowland forests of the Sunshine Coast hinterlands
  • Euoplos booloumba from the upland rainforest of the Conondales Range

These five new species put the total number of known spiny trapdoor spider species to 258.

Don’t be alarmed, bites from a trapdoor spider aren’t dangerous to humans.
Shutterstock

What happens now?

And so, the mystery was solved. Another small fraction of Australia’s beautiful biodiversity is known to science and can be preserved. But the story isn’t over just yet.

To properly conserve these species, we need to understand more about how they live. This is why the research team and I are undertaking a long-term study on one of these new species, Euoplos grandis from the Darling Downs. We hope to learn the intricacies of their lives and to track whether populations are declining from threats such as habitat destruction.




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We’re also continuing our mission to discover and describe new species of trapdoor spider, not just from Queensland, but from all around Australia.

The story of the Mount Tamborine trapdoor spider exemplifies the type of detective work Australian scientists undertake on all types of animal groups. But when it comes to invertebrates, we’ve barely scratched the surface, with new species of bugs, spiders, worms and more waiting to be discovered.

Working on discovering these invertebrates comes with a sense of urgency. These species need a name and formal protection, before it’s too late.

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Jeremy Wilson and Michael Rix from Queensland Museum were co-authors on this articleThe Conversation

Mark Harvey, Curator of Arachnology at the Western Australian Museum, Adjunct Professor, The University of Western Australia

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

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Almost 60 coral species around Lizard Island are ‘missing’ – and a Great Barrier Reef extinction crisis could be next


Michael Emslie

Zoe Richards, Curtin UniversityThe federal government has opposed a recommendation by a United Nations body that the Great Barrier Reef be listed as “in danger”. But there’s no doubt the natural wonder is in dire trouble. In new research, my colleagues and I provide fresh insight into the plight of many coral species.

Worsening climate change, and subsequent marine heatwaves, have led to mass coral deaths on tropical reefs. However, there are few estimates of how reduced overall coral cover is linked to declines in particular coral species.

Our research examined 44 years of coral distribution records around Lizard Island, at the northern end of the Great Barrier Reef. We found 16% of coral species have not been seen for many years and are at risk of either local extinction, or disappearing from parts of their local range.

This is alarming, because local extinctions often signal wider regional – and ultimately global – species extinction events.

Healthy coral near Lizard Island in 2011, top, then six years later after two bleaching events, bottom.
Healthy coral near Lizard Island in 2011, top, then six years later after two bleaching events, bottom.
Zoe Richards

Sobering findings

The Lizard Island reef system is 270 kilometres north of Cairns. It has suffered major disturbances over the past four decades: repeated outbreaks of crown-of-thorns seastars, category 4 cyclones in 2014 and 2015, and coral bleaching events in 2016, 2017 and 2020.

Our research focused on “hermatypic” corals around Lizard Island. These corals deposit calcium carbonate and form the hard framework of the reef.

We undertook hard coral biodiversity surveys four times between 2011 and 2020, across 14 sites. We combined the results with published and photographic species records from 1976 to 2020.

red fleshy coral with blue spots
Micromussa lordhowensis is popular in the aquarium trade.
Zoe Richards

Of 368 hard coral species recorded around Lizard Island, 28 (7.6%) have not been reliably recorded since before 2011 and may be at risk of local extinction. A further 31 species (8.4%) have not been recorded since 2015 and may be at risk of range reduction (disappearance from parts of its local range).

The “missing” coral species include:

  • Acropora abrotanoides, a robust branching shallow water coral that lives on the reef crest and reef flat has not been since since 2009
  • Micromussa lordhowensis, a low-growing coral with colourful fleshy polyps. Popular in the aquarium trade, it often grows on reef slopes but has not been seen since 2005
  • Acropora aspera, a branching coral which prefers very shallow water and has been recorded just once, at a single site, since 2011.

The finding that 59 coral species are at risk of local extinction or range reduction is significant. Local range reductions are often precursors to local species extinctions. And local species extinctions are often precursors to regional, and ultimately global, extinction events.

Each coral species on the reef has numerous vital functions. It might provide habitat or food to other reef species, or biochemicals which may benefit human health. One thing is clear: every coral species matters.




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reddish coral underwater
Acropa abrotanoides, one of the corals ‘missing’ from around Lizard Island.
Zoe Richards

A broader extinction crisis?

As human impacts and climate threats mount, there is growing concern about the resilience of coral biodiversity. Our research suggests such concerns are well-founded at Lizard Island.

Coral reef communities are dynamic, and so detecting species loss can be difficult. Our research found around Lizard Island, the diversity of coral species fluctuated over the past decade. Significant declines were recorded from 2011 to 2017, but diversity recovered somewhat in the three following years.

Local extinctions often happen incrementally and can therefore be “invisible”. To detect them, and to account for natural variability in coral communities, long-term biodiversity monitoring across multiple locations and time frames is needed.

Green coral
Acropora aspera has been recorded just once, at a single location, since 2011.
Anne Hoggett

In most locations however, data on the distribution and abundance of all coral species in a community is lacking. This means it can be hard to assess changes, and to understand the damage that climate change and other human-caused stressors are having on each species.

Only with this extra information can scientists conclusively say if the level of local extinction risk at Lizard Island indicates a risk that coral species may become extinct elsewhere – across the Great Barrier Reef and beyond.




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The Conversation


Zoe Richards, Senior Research Fellow, Curtin University

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

Australia’s threatened species plan has failed on several counts. Without change, more extinctions are assured


Euan Ritchie, Deakin University and Ayesha Tulloch, University of SydneyAustralia is globally renowned for its abysmal conservation record – in roughly 230 years we’ve overseen the extinction of more mammal species than any other nation. The federal government’s Threatened Species Strategy was meant to address this confronting situation.

The final report on the five-year strategy has just been published. In it, Threatened Species Commissioner Dr Sally Box acknowledges while the plan had some important wins, it fell short in several areas, writing:

…there is much more work to do to ensure our native plants and animals thrive into the future, and this will require an ongoing collective effort.

Clearly, Australia must urgently chart a course towards better environmental and biodiversity outcomes. That means reflecting honestly on our successes and failures so far.

How did the strategy perform?

The strategy, announced in 2015, set 13 targets linked to three focus areas:

  • feral cat management
  • improving the population trajectories of 20 mammal, 21 bird and 30 plant species
  • improving practices to recover threatened species populations.

Given the scale of the problem, five years was never enough time to turn things around. Indeed, as the chart below shows, the report card indicates five “red lights” (targets not met) and three “orange lights” (targets only partially met). It gave just five “green lights” for targets met.

Year Five - Final Report
Summary of the Threatened Species Strategy’s targets and outcomes.
Department of Agriculture, Water and the Environment

Falling short on feral cats

Feral cats were arguably the most prominent focus of the strategy, despite other threats requiring as much or more attention, such as habitat destruction via land clearing.

However, the strategy did help start a national conversation about the damage cats wreak on wildlife and ecosystems, and how this can be better managed.

In the five years to the end of 2020, an estimated 1.5 million feral cats were killed under the strategy – 500,000 short of the 2 million goal. But this estimate is uncertain due to a lack of systematic data collection. In particular, the number of cats culled by farmers, amateur hunters and shooters is under-reported. And more broadly, information is scattered across local councils, non-government conservation agencies and other sources.




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Australia’s feral cat population fluctuates according to rainfall, which determines the availability of prey – numbering between 2.1 million and 6.3 million. Limited investment in monitoring makes it impossible to know whether the average of 300,000 cats killed each year over the past five years will be enough for native wildlife to recover.

The government also failed in its goal to eradicate cats from five islands, only achieving this on Dirk Hartog Island off Western Australia. Importantly, that effort began in 2014, before the strategy was launched. And it was primarily funded by the WA government and an industry offset scheme, so the federal government can’t really claim this success.

On a positive note, ten mainland areas excluding feral cats have been established or are nearly complete. Such areas are a vital lifeline for some wildlife species and can enable native species reintroductions in the future.

feral cat holds dead bird
Feral cats were eradicated from just one island under the strategy.
Mark Marathon/Threatened Species Recovery Hub

Priority species: how did we do?

The strategy met its target of ensuring recovery actions were underway for at least 50 threatened plant species and 60 ecological communities. It also made good headway into storing all Australia’s 1,400 threatened plant species in seed banks. This is good news.

The bad news is that, even with recovery actions, the population trajectories of most priority species failed to improve. For the 24 out of about 70 priority species where population numbers were deemed to have “improved” over five years, about 30% simply got worse at a slower rate than in the decade prior. This can hardly be deemed a success.

Mala with baby in pouch
Populations of the mala, or Rufous Hare-wallaby, were improving before the strategy.
Wayne Lawler/Australian Wildlife Conservancy

What’s more, the populations of at least eight priority species, including the eastern barred bandicoot, eastern bettong, Gilbert’s potoroo, mala, woylie, numbat and helmeted honeyeater, were increasing before the strategy began – and five of these deteriorated under the strategy.

The finding that more priority species recovery efforts failed than succeeded means either:

  • the wrong actions were implemented
  • the right actions were implemented but insufficient effort and funding were dedicated to recovery
  • the trajectories of the species selected for action simply couldn’t be improved in a 5-year window.

All these problems are alarming but can be rectified. For example, the government’s new Threatened Species Strategy, released in May, contains a more evidence-based process for determining priority species.

For some species, it’s unclear whether success can be attributed to the strategy. Some species with improved trajectories, such as the helmeted honeyeater, would likely have improved regardless, thanks to many years of community and other organisation’s conservation efforts before the strategy began.

Conservation worker releases woylie
The improved outlook for some species is due to conservation efforts before the federal strategy.
WA Department of Environment and Conservation



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What must change

According to the report, habitat loss is a key threat to more than half the 71 priority species in the strategy. But the strategy does not directly address habitat loss or climate change, saying other government policies are addressing those threats.

We believe habitat loss and climate change must be addressed immediately.

Of the priority bird species threatened by land clearing and fragmentation, the trajectory of most – including the swift parrot and malleefowl – did not improve under the five years of the strategy. For several, such as the Australasian bittern and regent honeyeater, the trajectory worsened.

Preventing and reversing habitat loss will take years of dedicated restoration, stronger legislation and enforcement. It also requires community engagement, because much threatened species habitat is on private properties.

Effective conservation also requires raising public awareness of the dire predicament of Australia’s 1,900-plus threatened species and ecological communities. But successive governments have sought to sugarcoat our failings over many decades.

Bushfires and other extreme events hampered the strategy’s recovery efforts. But climate change means such events are likely to worsen. The risks of failure should form part of conservation planning – and of course, Australia requires an effective plan for emissions reduction.

The strategy helped increase awareness of the plight our unique species face. Dedicated community groups had already spent years volunteering to monitor and recover populations, and the strategy helped fund some of these actions.

However, proper investment in conservation – such as actions to reduce threats, and establish and maintain protected areas – is urgently needed. The strategy is merely one step on the long and challenging road to conserving Australia’s precious species and ecosystems.




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The Conversation


Euan Ritchie, Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University and Ayesha Tulloch, DECRA Research Fellow, University of Sydney

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

Australia’s threatened species plan sends in the ambulances but ignores glaring dangers


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Euan Ritchie, Deakin University; Ayesha Tulloch, University of Sydney, and Don Driscoll, Deakin UniversityAustralia is unquestionably in the midst of an extinction crisis. Some 34 native mammal species have been driven to extinction since European invasion, and threatened species and ecological communities now number more than 1,900.

On Friday, federal environment minister Sussan Ley released Australia’s second Threatened Species Strategy – a roadmap for combating threats to native plants, animals and ecological communities.

The ten-year plan builds on the first strategy launched in 2015, and contains welcome changes. But there remain serious questions about how the plan will be funded and implemented – and quite possibly undermined by other federal government policies.

In essence, the strategy sends a few extra ambulances to the bottom of the cliff, rather than installing a fence at the top to stop species tumbling over.

orange bellied parrot
The plan to save threatened species, such as the orange-bellied parrot, contains both improvements and concerns.
Shutterstock

First, the good news

It would be useful when assessing the new strategy to know how the previous one measured up. Unfortunately, federal environment officials have not yet released the last report card for that strategy, which makes it hard to identify what worked and what didn’t.

Nonetheless, the second strategy differs from the first in important ways.

The first strategy was criticised for its heavy focus on feral cats. Other problems which are just as (and often more) threatening to vulnerable species were not given the same attention. These include altered fire regimes, land clearing and other invasive species such as weeds and rabbits. Importantly, the new strategy recognises a greater number of key threats to wildlife and their habitats.

It also expands the number of actions for threatened species recovery from four to eight. Such actions may include tackling weeds and diseases, relocating species and identifying climate refuges.

The first strategy was rightly questioned for a somewhat myopic focus on 20 mammal, 20 bird and 30 plant species. It also lacked a transparent and evidence-based process for determining how a species was selected as a priority.

The new strategy could expand the types of species targeted for conservation to include fish, amphibian, reptile and invertebrate species. Also, the process for prioritising species for action promises to be more rigorous – assessed against six principles supported by science and existing conservation frameworks.

Significantly, priority places in need of conservation will likewise be assessed through a formal process. This is welcome if it ultimately protects habitats and broader ecosystems, an essential element of avoiding species extinctions.




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Tropical savanna in good condition.
Suzanne Prober

But challenges remain

The strategy talks of improving species trajectories, but it’s unclear what would constitute success in this regard.

If a threatened species’ population numbers were declining at a slower rate due to an intervention, would that intervention be deemed a success? Will successful actions be attributed to the strategy (and, by association, the federal government), even if they were entirely funded by philanthropic or community efforts?

Scientists have gone to great lengths to improve our knowledge about trends in threatened bird, mammal and plant species for which monitoring programs exist. However data for threatened species remains deficient, due to funding cuts for monitoring and associated infrastructure.

This means measuring progress on the strategy will be difficult, because we simply don’t have enough reliable data. And the strategy does not appear to remedy this situation with funding.

The strategy makes references to six important principles to guide decisions on which species are to be prioritised for assistance. These include how close a species is to extinction, a species’ ‘uniqueness’, the likelihood an intervention will work and whether the species is culturally significant. But these principles should not be applied in isolation from each other.

For example, it may be more cost efficient to save species with both a high chance of extinction and relatively cheap and effective interventions. But the most unique species may not be the cheapest to save, and the most endangered species may not be the species of greatest importance to one sector of the community.

So prioritisation may require trade-offs between different principles. There is no magic “one size fits all” solution, but excellent scientific guidance exists on how to keep this process objective, transparent and, most of all, repeatable.

The strategy acknowledges major drivers of biodiversity decline and extinction, including climate change, habitat destruction and pollution. However, nowhere is there an explicit declaration that to conserve or recover our species and environments we must tackle the underlying causes of these drivers.

The strategy also fails to acknowledge the key role legislation plays in reining in – or enabling – threats such as land clearing. An independent review earlier this year confirmed federal environment laws are failing abysmally. But fundamental recommendations stemming from the review, such as independent oversight and adequate resourcing, are not included in the strategy.




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Without stronger laws and funding, the southern brown bandicoot’s future is uncertain.
Sarah Maclagan

A better deal for nature

To be effective, the strategy must chart a path to effective environmental law reform.

And saving our threatened species and ecosystems shouldn’t be seen as a cost, but rather a savvy investment.

Increased and targeted funding for on-ground actions, such as weed and pest animal control, species re-introductions, and Indigenous ranger programs, could generate many thousands of jobs. Such measures would also boost local economies and support industries such as tourism.

A 2019 study found Australia’s listed threatened species could be recovered for about A$1.7 billion a year.

The Morrison government recently announced it would spend A$7 billion setting up a military space division to better protect satellites from attack.

What’s our best defence for an uncertain future? We argue it’s ensuring Earth’s life support systems, including its remarkable species and landscapes, are also protected.




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The Conversation


Euan Ritchie, Professor in Wildlife Ecology and Conservation, Centre for Integrative Ecology, School of Life & Environmental Sciences, Deakin University; Ayesha Tulloch, DECRA Research Fellow, University of Sydney, and Don Driscoll, Professor in Terrestrial Ecology, Deakin University

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

Attack of the alien invaders: pest plants and animals leave a frightening $1.7 trillion bill


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Corey J. A. Bradshaw, Flinders University; Boris Leroy, Muséum national d’histoire naturelle (MNHN); Camille Bernery, Université Paris-Saclay; Christophe Diagne, Université Paris-Saclay, and Franck Courchamp, Université Paris-SaclayThey’re one of the most damaging environmental forces on Earth. They’ve colonised pretty much every place humans have set foot on the planet. Yet you might not even know they exist.

We’re talking about alien species. Not little green extraterrestrials, but invasive plants and animals not native to an ecosystem and which become pests. They might be plants from South America, starfish from Africa, insects from Europe or birds from Asia.

These species can threaten the health of plants and animals, including humans. And they cause huge economic harm. Our research, recently published in the journal Nature, puts a figure on that damage. We found that globally, invasive species cost US$1.3 trillion (A$1.7 trillion) in money lost or spent between 1970 and 2017.

The cost is increasing exponentially over time. And troublingly, most of the cost relates to the damage and losses invasive species cause. Meanwhile, far cheaper control and prevention measures are often ignored.

Yellow crazy ants attacking a gecko
Yellow crazy ants, such as these attacking a gecko, are among thousands of invasive species causing ecological and economic havoc.
Dinakarr, CC0, Wikimedia Commons

An expansive toll

Invasive species have been invading foreign territories for centuries. They hail from habitats as diverse as tropical forests, dry savannas, temperate lakes and cold oceans.

They arrived because we brought them — as pets, ornamental plants or as stowaways on our holidays or via commercial trade.

The problems they cause can be:

  • ecological, such as causing the extinction of native species
  • human health-related, such as causing allergies and spreading disease
  • economic, such as reducing crop yields or destroying human-built infrastructure.

In Australia, invasive species are one of our most serious environmental problems – and the biggest cause of extinctions.

Feral animals such as rabbits, goats, cattle, pigs and horses can degrade grazing areas and compact soil, damaging farm production. Feral rabbits take over the burrows of native animals, while feral cats and foxes hunt and kill native animals.




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Wetlands in the Northern Territory damaged by invasive swamp buffalo (Bubalus bubalis)
Warren White

Introduced insects, such as yellow crazy ants on Christmas Island, pose a serious threat to a native species. Across Australia, feral honeybees compete with native animals for nectar, pollen and habitat.

Invasive fish compete with native species, disturb aquatic vegetation and introduce disease. Some, such as plague minnows, prey on the eggs and tadpoles of frogs and attack native fish.

Environmental weeds and invasive fungi and parasites also cause major damage.

Of course, the problem is global – and examples abound. In Africa’s Lake Victoria, the huge, carnivorous Nile perch — introduced to boost fisheries – has wiped out more than 200 of the 300 known species of cichlid fish — prized by aquarium enthusiasts the world over.

And in the Florida Everglades, thousands of five metre-long Burmese pythons have gobbled up small, native mammals at alarming rates.




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cichlid fish
In Africa, numbers of the beautiful cichlid fish have been decimated by Nile perch.
Shutterstock

Money talks

Despite the serious threat biological invasions pose, the problem receives little political, media or public attention.

Our research sought to reframe the problem of invasive species in terms of economic cost. But this was not an easy task.

The costs are diverse and not easily compared. Our analysis involved thousands of cost estimates, compiled and analysed over several years in our still-growing InvaCost database. Economists and ecologists helped fine-tune the data.

The results were staggering. We discovered invasive species have cost the world US$1.3 trillion (A$1.7 trillion) lost or spent between 1970 and 2017. The cost largely involves damages and losses; the cost of preventing or controlling the invasions were ten to 100 times lower.

Clearly, getting on top of control and prevention would have helped avoid the massive damage bill.




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Average costs have been increasing exponentially over time — trebling each decade since 1970. For 2017 alone, the estimated cost of invasive species was more than US$163 billion. That’s more than 20 times higher than the combined budgets of the World Health Organisation and the United Nations in the same year.

Perhaps more alarming, this massive cost is a conservative estimate and likely represents only the tip of the iceberg, for several reasons:

  • we analysed only the most robust available data; had we included all published data, the cost figure would have been 33 times higher for the estimate in 2017
  • some damage caused by invasive species cannot be measured in dollars, such as carbon uptake and the loss of ecosystem services such as pollination
  • most of the impacts have not been properly estimated
  • most countries have little to no relevant data.
A bucket by a lake with a sign reading 'Biosecurity station. Please dip your feet and nets'
Prevention strategies, such as biosecurity controls, are a relatively cheap way to deal with invasive species.
Shutterstock

Prevention is better than cure

National regulations for dealing with invasive species are patently insufficient. And because alien species do not respect borders, the problem also requires a global approach.

International cooperation must include financial assistance for developing countries where invasions are expected to increase substantially in the coming decades, and where regulations and management are most lacking.

Proactive measures to prevent invasion must become a priority. As the old saying goes, an ounce of prevention is better than a pound of cure. And this must happen early – if we miss the start of an invasion, control in many cases is impossible.

More and better research on the economic costs of biological invasions is essential. Our current knowledge is fragmented, hampering our understanding of patterns and trends, and our capacity to manage the problem efficiently.

We hope quantifying the economic impacts of invasive species will mean political leaders start to take notice. Certainly, confirmation of a A$1.7 trillion bill should be enough to get the ball rolling.




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The Conversation


Corey J. A. Bradshaw, Matthew Flinders Professor of Global Ecology and Models Theme Leader for the ARC Centre of Excellence for Australian Biodiversity and Heritage, Flinders University; Boris Leroy, Maître de conférences en écologie et biogéographie, Muséum national d’histoire naturelle (MNHN); Camille Bernery, Doctorante en écologie des invasions, Université Paris-Saclay; Christophe Diagne, Chercheur post-doctorant en écologie des invasions, Université Paris-Saclay, and Franck Courchamp, Directeur de recherche CNRS, Université Paris-Saclay

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

A new 3D koala genome will aid efforts to defend the threatened species


Parwinder Kaur, University of Western Australia

Koalas are unique in the animal kingdom, living on a eucalyptus diet that would kill other creatures and drinking so little their name comes from the Dharug word gula, meaning “no water”. Today, many koala populations across Australia are in decline, due to habitat destruction caused by agriculture, urbanisation, droughts and bushfires intensified by climate change, and diseases such as chlamydia and koala retrovirus.

Genetic information can play a key role in the effort to conserve koalas and other species. A detailed map of the koala genome is vital to understanding their susceptibility to disease, their genetic diversity, and how they may respond to new environmental pressures.

We have created a new “chromosome-length” sequence of the koala genome, which will allow researchers to study its three-dimensional structure and understand its evolution.




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A unique creature under threat

The modern koala is the only living representative of the marsupial family Phascolarctidae, a family that once included several genera and species. During the Oligocene and Miocene epochs (from 34 to 5 million years ago), the ancestors of modern koalas lived in rainforests and didn’t eat only leaves.

During the Miocene, the Australian continent began drying out, leading to the decline of rainforests and the spread of open eucalyptus woodlands. Koalas evolved several adaptations that allowed them to live on a specialised eucalyptus diet. This specialisation makes them picky eaters, so they’re very prone to habitat loss.

Koalas are listed as a vulnerable species by the International Union for Conservation of Nature. It was hunted heavily in the early 20th century for its fur, and large-scale cullings in Queensland resulted in public outcry, initiating a movement to protect the species. Sanctuaries were established, and koalas whose habitat was disappearing were relocated.

Koalas are particularly vulnerable to bushfires; they are slow moving and eucalypt trees are very flammable. They instinctively seeks refuge in higher branches, exposing them to intense heat and flames. Bushfires also fragment the animal’s habitat, which restricts their movement and leads to population decline and loss of genetic diversity.

Piecing together the puzzle

The koala genome was first sequenced in 2013. This was only the first step in understanding koala genetics — akin to finding all the pieces of the puzzle, but being unsure how to put them all together into the meaningful patterns of genes and chromosomes.

Our new chromosome-length assembly follows the work of others, especially the Koala Genome Consortium and the Koala Genome Project led by Australian geneticist Rebecca Johnson. It is based on a draft by the Earlham Institute in the UK.

We used big-data sequencing methods such as Hi-C, 3D-DNA and Juicebox Assembly Tools courtesy of DNA Zoo labs to create our chromosome-length assembly.

We organised the genome into 8 chromosomes, a great improvement on the draft of 1,907 fragments we began with.

Vital for conservation

A high-quality genome sequence is essential if we want to bring genetic insights to conservation management initiatives. Some 200 Australian vertebrate species currently have species recovery plans, and 80% of those plans include genome-based actions. However, only 15% of those species have any genomic data available.

Our chromosome-length koala genome assembly enables a highly detailed 3D view of the genome architecture for koala. It is easier to use than earlier genomes, and means conservation management initiatives will have fast, cost-effective and reliable analysis options available.

This will give us insights into koalas’ genetic susceptibility to diseases like koala retrovirus (KoRV) and chlamydia. It may also form a basis for innovative vaccines. What’s more, it can be used in new conservation management strategies that aim to diversify the koala gene pool.




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The Conversation


Parwinder Kaur, Associate Professor | Director, DNA Zoo Australia, University of Western Australia

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

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.




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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.




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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.




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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.




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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.




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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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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/