Category: Endangered species

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

by 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 University

Australia 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. [View the complete list of endangered frog species]

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.

EPA determines three agricultural insecticides could threaten endangered species

Read the full story at The Hill.

The Environmental Protection Agency (EPA) on Thursday released draft evaluations identifying three common agricultural insecticides as likely harmful to the majority of endangered plants and animals, including all 38 endangered amphibians.

To save a huge, 24-armed sea creature, scientists become loving foster parents

Read the full story from NPR.

On an island off the coast of Washington state, scientists have resorted to breeding sunflower sea stars in a lab. It’s a desperate attempt to save the endangered animals from disappearing completely.

Rare chameleon species is found ‘clinging to survival’

Read the full post at Treehugger.

A tiny species of chameleon thought to be extinct due to habitat loss because of deforestation has been found by researchers.

New IUCN green status launched to help species ‘thrive, not just survive’

Read the full story in The Guardian.

Conservation tool will focus on recovery efforts to give a fuller picture of threats to plant and animal populations.

Instead of braving the river, these endangered salmon take the highway

Read the full story at Phys.org.

Billions of dollars have been spent over the last four decades to save Snake River salmon by restoring streams, relocating sea lions and other predators, building hatcheries and helping fish get past dams. But those efforts increasingly look futile.

As heat waves become more common and river temperatures rise, few fish complete the treacherous journey from the Pacific Ocean through eight dams to their spawning grounds in southern Idaho—a 900-mile trip up the Columbia and Snake rivers and their tributaries.

Hoping to avert disaster amid record July heat, the National Oceanic and Atmospheric Administration authorized an emergency plan to help the sockeye skip the final 300 miles of their migration.

Climate change: world’s lakes are in hot water – threatening rare wildlife

Jdross75/Shutterstock

by Antonia Law (Keele University)

The Earth’s surface is splotched with 117 million lakes. Some are scarcely more than ponds, while others are so big they can be seen from space. At 395 miles long, 49 miles wide and just over 1 mile deep, Lake Baikal in Siberia is one of the world’s largest and it’s home to 2,500 species, including the Baikal seal – Earth’s only species of freshwater seal.

Lakes and rivers occupy just 1% of the Earth’s surface but are incredible hotspots for biodiversity, sheltering 10% of all species globally. Particularly in older and deeper lakes, life has had millions of years to evolve and adapt to the peculiarities of that habitat, giving rise to unique forms. But since 1970, numbers of freshwater vertebrates, including birds, fish, amphibians, reptiles and mammals, have declined by a staggering 83% through the extraction of lake water, pollution, invasive species and disease. Now, climate change threatens to drive even deeper losses.

Lake heatwaves – when surface water temperatures rise above their average for longer than five days – are a relatively new phenomenon. But by the end of this century, heatwaves could last between three and 12 times longer and become 0.3°C to 1.7°C hotter. In some places, particularly near the equator, lakes may enter a permanent heatwave state. Smaller lakes may shrink or disappear entirely, along with the wildlife they contain, while deeper lakes will face less intense but longer heatwaves.

In a new study, researchers examined 393 lakes worldwide between 1981 and 2017 and found their temperatures rose by 0.39°C every decade, while dissolved oxygen fell by 5% at the surface and 19% in the depths. It’s in these cooler, deeper parts of lakes where trout, burbot and salmon usually thrive thanks to sufficient oxygen, especially in the summer. Largely due to warming air temperatures, 68% of the lakes in the study had lost this important niche to rising temperatures and falling oxygen levels.

So what do these changes mean for the other forms of life that call lakes home?

How lake life will change

Most organisms that live in lakes can only thrive in water with just the right temperature and concentration of nutrients and oxygen. Warmer lakes hold less oxygen and lose more water through evaporation, forcing species to live in saltier and less oxygenated habitats.

Things won’t be easy for species which live above the water for most of their lives either. Dragonflies are a common sight flitting among the reeds on the lake side. They lay their eggs in the shallows, but as lakes are lowered or dry out during more frequent and severe heatwaves, this protection is lost. Those larvae which survive are likely to emerge early, when food and habitat may be lacking.

Climate change will shift the types of organisms we find in lakes. Cold water fish, such as trout and salmon, need cooler temperatures and higher oxygen concentrations than warm water species such as largemouth bass and white perch. One cold-loving species, Arctic char, could vanish from 73% of its Swedish range by 2100 just as a result of warming. Meanwhile, rising temperatures could mean parasites that infect fish grow faster and larger. In one study, parasitic worms infecting stickleback fish grew four times faster in water at 20°C compared to 15°C.

Heatwaves could accelerate the spread and size of pathogens in fish, with huge consequences for the aquaculture industry and wild populations. Human diseases, transmitted by freshwater organisms, may also increase. Naegleria fowleri is a lake parasite that flourishes in warmer temperatures. Known as the brain-eating amoeba, this microbe can cause fatal meningoencephalitis if it enters the body through the nose. Prolonged periods when lake waters remain warmer than average could see this parasite expand into more temperate waters.

Since warmer surface waters hold more nutrients, climate change could cause an explosion in the number of microscopic algae that live in lakes. These microorganisms are the base of the food web and the foundation of life in these habitats. But this isn’t the good news it seems. When nutrients are abundant, huge quantities of these algae can form a thick green (or sometimes red) blanket on the lake surface. These algal blooms not only look unsightly, they often produce harmful toxins.

Heatwaves are increasing the frequency of harmful algal blooms and causing mass mortality events where thousands of animals die in a few days. Algal blooms block out the light and suffocate fish, either by crashing oxygen levels or clogging up their gills. A 100 metre-wide, 15cm-deep algal bloom in Loch Leven in Scotland in 1992 killed 1,000 brown trout over 24 hours.

Six dead fish float in algae-choked water.
Lake algal blooms are likely to be more frequent and severe as Earth warms. O Partime Photo/Shutterstock

Unlike those living elsewhere, most lake animals cannot simply move to another habitat once their lake becomes uninhabitable. But even migratory species will suffer. In August 2004, 15,000 flamingos died on a lake in Tanzania after consuming toxins produced by algal blooms.

As heatwaves proliferate and oxygen levels decline, mass fish die-offs are predicted to double from the 2040s in lakes in the northern hemisphere and increase fourfold in the southern hemisphere from the 2080s onwards. Without immediate action to curb emissions and slow climate change, many of the world’s lakes are on course for a sweltering, breathless and lifeless future.

Antonia Law, Lecturer in Physical Geography, Keele University

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

When conservation work pays off: After 20 years, the Saker Falcon breeds again in Bulgaria

Read the full story from Pensoft Publishers.

Considered extinct as a breeding species in the early 2000s, the Saker Falcon was recovered when the first active nest from the new history of the species in Bulgaria was discovered in 2018, built by two birds that were reintroduced back in 2015.

Amid climate pressures, a call for a plan to move endangered species

Read the full story from e360.

The conservation community has fiercely debated whether to help species move as climate change and habitat loss threaten more extinctions. Now, scientists are calling on an upcoming international conference to set guidelines for this complex – and potentially risky – challenge.

A new approach to identify genetic boundaries of species could also impact policy

Read the full story from San Diego State University.

A new approach to genomic species delineation could impact policy and lend clarity to legislation for designating a species as endangered or at risk. Evolutionary biologists model the process of speciation, which follows population formation, improving on current species delineation methods.

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