We name the 26 Australian frogs at greatest risk of extinction by 2040 — and how to save them


Spotted tree frog.
Michael Williams/Its A Wildlife Photography, Author provided

Graeme Gillespie, The University of Melbourne; Conrad Hoskin, James Cook University; Hayley Geyle, Charles Darwin University; Jaana Dielenberg, Charles Darwin University; Nicola Mitchell, The University of Western Australia, and Stephen Garnett, Charles Darwin UniversityAustralia is home to more than 240 frog species, most of which occur nowhere else. Unfortunately, some frogs are beyond help, with four Australian species officially listed as extinct.

This includes two remarkable species of gastric-brooding frog. To reproduce, gastric-brooding frogs swallowed their fertilised eggs, and later regurgitated tiny baby frogs. Their reproduction was unique in the animal kingdom, and now they are gone.

Our new study published today, identified the 26 Australian frogs at greatest risk, the likelihood of their extinctions by 2040 and the steps needed to save them.

Tragically, we have identified an additional three frog species that are very likely to be extinct. Another four species on our list are still surviving, but not likely to make it to 2040 without help.

#1 The northern gastric-brooding frog (Rheobatrachus vitellinus) is likely already extinct, primarily due to chytrid fungus disease.
Hal Cogger

The 26 most imperilled frogs

The striking yellow-spotted tree frog (in southeast Australia), the northern tinker frog and the mountain mist frog (both in Far North Queensland) are not yet officially listed as extinct – but are very likely to be so. We estimated there is a greater than 90% chance they are already extinct.

The locations of the top 26 Australian frogs at risk of extinction. ** Species likely to be recently extinct. * Species more likely than not to become extinct by 2040 unless there is action.
Jaana Dielenberg/Threatened Species Recovery Hub

The next four most imperilled species are hanging on in the wild by their little frog fingers: the southern corroboree frog and Baw Baw frog in the Australian Alps, and the Kroombit tinker frog and armoured mist frog in Queensland’s rainforests.

The southern corroboree frog, for example, was formerly found throughout Kosciuszko National Park in the Snowy Mountains. But today, there’s only one small wild population known to exist, due largely to an introduced disease.

Without action it is more likely than not (66% chance) the southern corroboree frog will become extinct by 2040.

#6 The southern corroboree frog (Pseudophryne corroboree) is close to extinction.
David Hunter/DPIE NSW
#3 The yellow-spotted tree frog (Litoria castanea) is likely extinct. It was once common throughout the New England Tableland and Southern Tablelands region in NSW, and the ACT. It is sensitive to chytrid fungus disease and also impacted by climate change, habitat loss and invasive fish.
David Hunter/DPIE NSW

What are we up against?

Species are suffering from a range of threats. But for our most recent extinctions and those now at greatest risk, the biggest cause of declines is the amphibian chytrid fungus disease.

This introduced fungus is thought to have arrived in Australia in the 1970s and has taken a heavy toll on susceptible species ever since. Cool wet environments, such as rainforest-topped mountains in Queensland where frog diversity is particularly high, favour the pathogen.

The fungus feeds on the keratin in frogs’ skin — a major organ that plays a vital role in regulating moisture, exchanging respiratory gases, immunity, and producing sunscreen-like substances and chemicals to deter predators.

Dead frog
Chrytrid disease killed this green-eyed tree frog.
Robert Puschendorf
#8 Armoured mist frog (Litoria lorica) populations have been decimated by chytrid fungus disease. It has been lost throughout former mountainous rainforest habitats where the fungus thrives. Without effective action, it’s likely to be extinct within 20 years.
Conrad Hoskin

Another major emerging threat is climate change, which heats and dries out moist habitats. It’s affecting 19 of the imperilled species we identified, such as the white-bellied frog in Western Australia, which develops tadpoles in little depressions in waterlogged soil.

Climate change is also increasing the frequency, extent and intensity of fires, which have impacted half (13) of the identified species in recent years. The Black Summer fires ravaged swathes of habitat where fires should rarely occur, such as mossy alpine wetlands inhabited by the northern corroboree frog.

Invasive species impact ten frog species. For the spotted tree frog in southern Australia, introduced fish such as brown and rainbow trout are the main problem, as they’re aggressive predators of tadpoles. In northern Australia, feral pigs often wreak havoc on delicate habitats.

#15 The Kuranda tree frog (Litoria myola) is found in a very small area near Cairns. Its primary threat is loss and degradation of habitat due to development.
Conrad Hoskin
#20 The white-bellied frog (Geocrinia alba) is the Western Australian frog at greatest risk of extinction. The tadpoles of this tiny terrestrial breeding frog rely on wet soil to develop. Reduced rainfall is contributing to declines.
Emily Hoffmann

So what can we do about it?

We identified the key actions that can feasibly be implemented in time to save these species. This includes finding potential refuge sites from chytrid and from climate change, reducing bushfire risks and reducing impacts of introduced species.

But for many species, these actions alone aren’t enough. Given the perilous state of some species in the wild, captive conservation breeding programs are also needed. But they cannot be the end goal.

#11 A northern corroboree frog in the captive breeding program run by the ACT Government.
Peter Taylor/Threatened Species Recovery Hub

Captive breeding programs can not only establish insurance populations, they can also help a species persist in the wild by supplying frogs to establish populations at new suitable sites.

Boosting numbers in existing wild populations with captive bred frogs improves their chance of survival. Not only are there more frogs, but also greater genetic diversity. This means the frogs have a better chance of adapting to new conditions, including climate change and emerging diseases.

Our knowledge of how to breed frogs in captivity has improved dramatically in recent decades, but we need to invest in doing this for more frog species.

Please save these frogs: The 26 Australian species at greatest risk of extinction.

Finding and creating wild refuges

Another vital way to help threatened frogs persist in the wild is by protecting, creating and expanding natural refuge areas. Refuges are places where major threats are eliminated or reduced enough to allow a population to survive long term.

For the spotted-tree frog, work is underway to prevent the destruction of frog breeding habitat by deer, and to prevent tadpoles being eaten by introduced predatory fish species. These actions will also help many other frog species as well.

The chytrid fungus can’t be controlled, but fortunately it does not thrive in all environments. For example, in the warmer parts of species’ range, pathogen virulence may be lower and frog resilience may be higher.

Chytrid fungus completely wiped out the armoured mist frog from its cool, wet heartland in the uplands of the Daintree Rainforest. But, a small population was found surviving at a warmer, more open site where the chytrid fungus is less virulent. Conservation for this species now focuses on these warmer sites.

This strategy is now being used to identify potential refuges from chytrid for other frog species, such as the northern corroboree frog.

Dr Graeme Gillespie during a survey for the spotted-tree frog.
Michael Williams/Its A Wildlife Photography

No time to lose

We missed the window to save the gastric-brooding frogs, but we should heed their cautionary tale. We are on the cusp of losing many more unique species.

Decline can happen so rapidly that, for many species, there is no time to lose. Apart from the unknown ecological consequences of their extinctions, the intrinsic value of these frogs means their losses will diminish our natural legacy.

In raising awareness of these species we hope we will spark new action to save them. Unfortunately, despite persisting and evolving independently for millions of years, some species can now no longer survive without our help.

The Conversation

Graeme Gillespie, Honorary Research Fellow, The University of Melbourne; Conrad Hoskin, Lecturer/ABRS Postdoctoral Fellow, James Cook University; Hayley Geyle, Research Assistant, Charles Darwin University; Jaana Dielenberg, University Fellow, Charles Darwin University; Nicola Mitchell, Associate Professor in Conservation Physiology, The University of Western Australia, and Stephen Garnett, Professor of Conservation and Sustainable Livelihoods, Charles Darwin University

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

Massive road and rail projects could be Africa’s greatest environmental challenge


Bill Laurance, James Cook University

Africa’s natural environments and spectacular wildlife are about to face their biggest challenge ever. In a paper published today in Current Biology, my colleagues and I assess the dramatic environmental changes that will be driven by an infrastructure-expansion scheme so sweeping in scope, it is dwarfing anything the Earth’s biggest continent has ever been forced to endure.

People, food and mining

Africa’s population is exploding – expected nearly to quadruple this century, according to the United Nations. With that, comes an escalating need to improve food production and food security.

In addition, Africa today is experiencing a frenzy of mining activity, with most of the investment coming from overseas. China, for instance, is investing over US$100 billion annually, with India, Brazil, Canada and Australia also being big foreign investors.

To feed its growing population and move its minerals to shipping ports for export, Africa needs better roads and railroads. When located in the right places, improved transportation can do a lot of good. It makes it easier for farmers to get access to fertiliser and new farming technologies, and cheaper to get crops to urban markets with less spoilage. It can also encourage rural investment while improving livelihoods, access to health services, and education for local residents.

Improved transportation is especially important for Africa’s agriculture, which is badly under-performing. In many areas, large “yield gaps” exist between what could be produced under ideal conditions and what is actually being produced. With better farming, Africa’s yields could be doubled or even tripled without clearing one more hectare of land.

Using rudimentary methods, small-scale farmers eke out a living in Gabon.
William Laurance

Pandora’s box

However, there is another side to new transportation projects — a dark side, especially for the environment. When located in areas with high environmental values, new roads or railroads can open a Pandora’s box of problems.

Roads slicing into remote areas can lead to range of legal and illegal human land uses. For instance, in the Amazon, 95% of all deforestation occurs within five kilometres of a road; and for every kilometre of legal road there are three kilometres of illegal roads. In the Congo Basin, forest elephants decline sharply, and signs of hunters and poachers increase, up to 50 kilometres from roads.

A forest elephant shot by poachers.
Ralph Buij

In the wrong places, roads can facilitate invasions of natural areas by illegal miners, colonists, loggers and land speculators. In my view, the explosive expansion of roads today is probably the greatest single peril to the world’s natural environments and wildlife.

Africa’s ‘development corridors’

Earlier studies that my colleagues and I conducted, including a major study published in Nature last year, suggest Africa is likely to be a global epicentre of environmental conflict. A key reason: an unprecedented scheme to dramatically expand African roads, railroads and energy infrastructure.

In total, we have identified 33 massive “development corridors” that are being proposed or are underway. At the heart of each corridor is a road or railroad, sometimes accompanied by a pipeline or power line.

The 33 development corridors that are being proposed or constructed in sub-Saharan Afirca.
William F. Laurance et al. (2015) Current Biology.

The projects have a variety of proponents, including the African Development Bank, national governments, international donors and lenders, and commercial agricultural and mining interests. They’re intended to promote large-scale development and their scope is breathtaking.

If completed in their entirety, the corridors will total over 53,000 kilometres in length, crisscrossing the African continent. Some individual corridors are over 4,000 kilometres long.

Will these corridors generate key social and economic benefits, or will they cause great environmental harm? To address this question, we looked at three factors, focusing on a 50-kilometre-wide band laid over the top of each corridor.

First, we assessed the “natural values” of each corridor, by combining data on its biodiversity, endangered species, critical habitats for wildlife, and the carbon storage and climate-regulating benefits of its native vegetation.

Second, we mapped human populations near each corridor, using satellite data to detect nightlights from human settlements (to avoid lands that were simply being burned, we included only places with “persistent” nightlights). We then combined the natural-value and population data to generate a conservation-value score for each corridor, reasoning that sparsely populated areas with high natural values have the greatest overall conservation value.

Finally, we estimated the potential for new roads or railroads to increase food production. Areas that scored highly had soils and climates suitable for farming but large yield gaps, were within several hours’ drive of a city or port, and were projected to see large future increases in food demand.

Costs versus benefits

When we compared the conservation value of each corridor with its potential agricultural benefits, we found huge variation among the corridors.

A two-minute video summary of our study’s main findings

A half dozen of the corridors look like a really good idea, with large benefits and limited environmental costs. However, another half dozen seem like a really bad idea, in that they’d damage critical environments, especially rainforests of the Congo Basin and West Africa and biologically rich equatorial savanna regions.

In the middle, there are 20 or so corridors that appear “marginal”. These tend to have high environmental values and high potential agricultural benefits, or vice versa.

We argue that these marginal projects should be evaluated in detail, on a case-by-case basis. If they do proceed, it should only happen under the most stringent conditions, with careful environmental assessment and land-use planning, and with specific measures in place (such as new protected areas) to limit or mitigate their impacts.

Dangers for Africa

There’s no such thing as a free ride. For Africa, the dangers of the development corridors are profound. Even if well executed, we estimate that the current avalanche of corridors would slice through over 400 protected areas and could easily degrade another 2,000 or so. This bodes poorly for Africa’s wildlife and biodiversity generally.

Wild zebras in the Serengeti.
William Laurance

Beyond this, the corridors will encourage human migration into many sparsely populated areas with high environmental values. The wild card in all this is the hundreds of billions of dollars of foreign investments pouring into Africa each year for mining. Even if a corridor is likely to yield only modest benefits for food production, it may be very difficult for governments and decision makers to say no to big mining investors.

The bottom line: it could be a fraught battle to stop even ill-advised development corridors, though not impossible. If we shine a bright light on the corridors and argue strongly that those with limited benefits and large costs are a bad idea, we may succeed in stopping or at least delaying some of the worst of them.

This is unquestionably a vital endeavour. Africa is changing faster than any continent has ever changed in human history, and it is facing unprecedented socioeconomic and environmental challenges.

The next few decades will be crucial. We could promote relatively sustainable and equitable development — or end up with an impoverished continent whose iconic natural values and wildlife have been irretrievably lost.

The Conversation

Bill Laurance, Distinguished Research Professor and Australian Laureate, James Cook University

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

Canada: The Peace-Athabasca Delta Under Threat


One of the world’s greatest freshwater deltas, the Peace-Athabasca Delta in Canada, is facing a number of threats.

For more visit:
http://e360.yale.edu/feature/canadas_great_inland_delta_precarious_future_looms/2709/