Dead, shrivelled frogs are unexpectedly turning up across eastern Australia. We need your help to find out why


Green Tree Frog
Jodi Rowley, Author provided

Jodi Rowley, Australian Museum and Karrie Rose, University of SydneyOver the past few weeks, we’ve received a flurry of emails from concerned people who’ve seen sick and dead frogs across eastern Victoria, New South Wales and Queensland.

One person wrote:

About a month ago, I noticed the Green Tree Frogs living around our home showing signs of lethargy & ill health. I was devastated to find about 7 of them dead.

Another wrote:

We previously had a very healthy population of green tree frogs and a couple of months ago I noticed a frog that had turned brown. I then noticed more of them and have found numerous dead frogs around our property.

And another said she’d seen so many dead frogs on her daily runs she had to “seriously wonder how many more are there”.

So what’s going on? The short answer is: we don’t really know. How many frogs have died and why is a mystery, and we’re relying on people across Australia to help us solve it.

Why are frogs important?

Frogs are an integral part of healthy Australian ecosystems. While they are usually small and unseen, they’re an important thread in the food web, and a kind of environmental glue that keeps ecosystems functioning. Healthy frog populations are usually a good indication of a healthy environment.

The stony creek frog is one of the species hit by this mysterious outbreak.
Jodi Rowley, Author provided

They eat vast amounts of invertebrates, including pest species, and they’re a fundamental food source for a wide variety of other wildlife, including birds, mammals and reptiles. Tadpoles fill our creeks and dams, helping keep algae and mosquito larvae under control while they too become food for fish and other wildlife.

But many of Australia’s frog populations are imperilled from multiple, compounding threats, such as habitat loss and modification, climate change, invasive plants, animals and diseases.

Although we’re fortunate to have at least 242 native frog species in Australia, 35 are considered threatened with extinction. At least four are considered extinct: the southern and northern gastric-brooding frogs (Rheobatrachus silus and Rheobatrachus vitellinus), the sharp-snouted day frog (Taudactylus acutirostris) and the southern day frog (Taudactylus diurnus).

A truly unusual outbreak

In most circumstances, it’s rare to see a dead frog. Most frogs are secretive in nature and, when they die, they decompose rapidly. So the growing reports of dead and dying frogs from across eastern Australia over the last few months are surprising, to say the least.

While the first cold snap of each year can be accompanied by a few localised frog deaths, this outbreak has affected more animals over a greater range than previously encountered.

This is truly an unusual amphibian mass mortality event.

In this outbreak, frogs appear to be either darker or lighter than normal, slow, out in the daytime (they’re usually nocturnal), and are thin. Some frogs have red bellies, red feet, and excessive sloughed skin.

A browned, shrivelled green tree frog
A browned, shrivelled green tree frog (Litoria caerulea)
Suzanne Mcgovern, Author provided

The iconic green tree frog (Litoria caeulea) seems hardest hit in this event, with the often apple-green and plump frogs turning brown and shrivelled.

This frog is widespread and generally rather common. In fact, it’s the ninth most commonly recorded frog in the national citizen science project, FrogID. But it has disappeared from parts of its former range.

Other species reported as being among the sick and dying include Peron’s tree frog (Litoria peronii), the Stony Creek frog (Litoria lesueuri), and green stream frog (Litoria phyllochroa). These are all relatively common and widespread species, which is likely why they have been found in and around our gardens.

We simply don’t know the true impacts of this event on Australia’s frog species, particularly those that are rare, cryptic or living in remote places. Well over 100 species of frog live within the geographic range of this outbreak. Dozens of these are considered threatened, including the booroolong Frog (Litoria booroolongensis) and the giant barred frog (Mixophyes iteratus).

The giant barred frog is a threatened species that lives in the geographic range of this outbreak.
Jodi Rowley, Author provided

So what might be going on?

Amphibians are susceptible to environmental toxins and a wide range of parasitic, bacterial, viral and fungal pathogens. Frogs globally have been battling it out with a pandemic of their own for decades — a potentially deadly fungus often called amphibian chytrid fungus.

This fungus attacks the skin, which frogs use to breathe, drink, and control electrolytes important for the heart to function. It’s also responsible for causing population declines in more than 500 amphibian species around the world, and 50 extinctions.

For example, in Australia the bright yellow and black southern corroboree frog (Pseudophryne corroboree) is just hanging on in the wild, thanks only to intensive management and captive breeding.

The teeny tiny southern corroborree frogs have been hit hard by the chytrid fungus.
Jodi Rowley, Author provided

Curiously, some other frog species appear more tolerant to the amphibian chytrid fungus than others. Many now common frogs seem able to live with the fungus, such as the near-ubiquitous Australian common eastern froglet (Crinia signifera).

But if frogs have had this fungus affecting them for decades, why are we seeing so many dead frogs now?




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A deadly fungus threatens to wipe out 100 frog species – here’s how it can be stopped


Well, disease is the outcome of a battle between a pathogen (in this case a fungus), a host (in this case the frog) and the environment. The fungus doesn’t do well in warm, dry conditions. So during summer, frogs are more likely to have the upper hand.

In winter, the tables turn. As the frog’s immune system slows, the fungus may be able to take hold.

Of course, the amphibian chytrid fungus is just one possible culprit. Other less well-known diseases affect frogs.

The near-ubiquitous Austrlaian common eastern froglet is one species that seems able to live with the devastating chytrid fungus.
Jodi Rowley, Author provided

To date, the Australian Registry of Wildlife Health has confirmed the presence of the amphibian chytrid fungus in a very small number of sick frogs they’ve examined from the recent outbreak. However, other diseases — such as ranavirus, myxosporean parasites and trypanosome parasites — have also been responsible for native frog mass mortality events in Australia.

It’s also possible a novel or exotic pathogen could be behind this. So the Australian Registry of Wildlife Health is working with the Australian Museum, government biosecurity and environment agencies as part of the investigation.

Here’s how you can help

While we suspect a combination of the amphibian chytrid fungus and the chilly temperatures, we simply don’t know what factors may be contributing to the outbreak.

Why green tree frogs are dying en masse is still a mystery.
Sophie Hendry, Author provided

We also aren’t sure how widespread it is, what impact it will have on our frog populations, or how long it will last.

While the temperatures stay low, we suspect our frogs will continue to succumb. If we don’t investigate quickly, we will lose the opportunity to achieve a diagnosis and understand what has transpired.

We need your help to solve this mystery.

Please send any reports of sick or dead frogs (and if possible, photos) to us, via the national citizen science project FrogID, or email calls@frogid.net.au.




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The Conversation


Jodi Rowley, Curator, Amphibian & Reptile Conservation Biology, UNSW, Australian Museum and Karrie Rose, Australian Registry of Wildlife Health – Taronga Conservation Society Australia, University of Sydney

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

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Bushfires left millions of animals dead. We should use them, not just bury them


Emma Spencer, University of Sydney; Chris Dickman, University of Sydney; Philip Barton, Australian National University, and Thomas Newsome, University of Sydney

Bushfires this season have left an estimated 1 billion dead animals in their wake, their carcasses dotting the blackened landscape.

Adding to the toll, farmers are being forced to euthanise injured and starving livestock and there are also calls to cull feral animals in fire-affected areas, including by aerial shooting.

The carcasses have already been flagged as a potential biosecurity threat, and the Australian Defence Force is tasked with collecting and burying the dead in mass graves.




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Australia’s bushfires could drive more than 700 animal species to extinction. Check the numbers for yourself


There’s logic in this. Carcasses can harbour nasty diseases such as botulism that threaten human, livestock and wildlife health. They also provide food for invasive pests like feral cats and red foxes.

But carcasses can play a positive role as landscapes recover from fire, providing rich nutrients for other native animal, microbial and plant species.

Carcasses provide important food sources to native animals, such as the lace goanna.

The Morrison Government has announced a A$50 million package to help wildlife and habitat recover from the fires, and yesterday met leading wildlife experts and environment groups to get advice on the recovery process.

We suggest this process should examine carcass disposal methods other than burial, such as composting – effectively “recycling” the dead. It should also involve monitoring the carcasses that remain to understand both their positive and negative roles in fire-ravaged areas.

The positives: carcasses feed the living

Carcasses feed a range of native animals, including goannas, wedge-tailed eagles and dingoes. Post-fire, they can provide an alternative source of food for struggling native predators and pollinators. And feeding hungry predators with carcasses could redirect them away from vulnerable prey.

Carcasses also feed insects such as flies, ants, beetles, and their larvae, and support important ecological processes such as pollination.

As they decompose, nutrients leach from carcasses into the surrounding environment and create “halos” of greenery in the landscape, where vegetation thrives around carcass sites. Their influence on soil and plant communities can last for years.

Vegetation growth ‘halo’ around a kangaroo carcass. When animals die their nutrients can influence the landscape for years.

The negatives: spreading disease and sustaining feral animals

Carcasses are home to bacteria that help break down animal tissues. But some carcasses also harbour harmful pathogens that bring disease.

For a disease outbreak to happen, the animal must generally have already been carrying dangerous infectious agents, like Anthrax or the Hendra virus, before they died. And many of these pathogens will not survive long on dead hosts.




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Predators get the advantage when bushfires destroy vegetation


Leaving carcasses out in the open can also feed introduced predators such as feral cats and red foxes, putting small native animals at risk. Some weeds thrive in the nutrient-rich soils around carcasses too.

Introduced insects like the European wasp, which appeared en masse following fires in Kosciuszko National Park, also take advantage of carcass resources. These wasps are highly aggressive and attack and kill other native insects.

How long does a carcass stick around?

We know very little about the ecological role of carcasses in fire-affected areas, and it’s important that more research is carried out.

We know burnt animals can decompose faster than other carcasses and harbour different types of insect scavengers.

However the recent fires are likely to have wiped out entire scavenger communities, including larger scavengers like dingoes and eagles, that help to clean our landscapes of dead animals.

The effects of this are unknown, but could mean that carcasses stick around in the environment for prolonged periods, even months.

A feral cat scavenging on an animal carcass. Animal carcasses could increase the number of feral predators.

Finding the right solution to a grisly problem

As climate change accelerates the number of natural disasters and mass animal deaths, more thought and planning must be put into carcass management.

In Australia, carcasses are often dealt with by not dealing with them: they’re left to rot. This happened for almost 100 feral horses that died last year at an empty water hole during a heatwave.

Animals culled in national parks and on farmlands are also often left to decay, untouched, as are the many dead animals that commonly line our country roads. But in landscapes where feral species are common, or where livestock or people are likely to encounter carcasses, leaving them alone isn’t the best option.




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A season in hell: bushfires push at least 20 threatened species closer to extinction


Carcasses are more often buried following disease outbreaks or when livestock die. We saw this during the 2019 Queensland floods, where thousands of drowned cattle were buried in mass graves.

Burial is a relatively inexpensive, fast and effective method of dealing with the dead. But it must be done carefully to avoid polluting groundwater sources and causing nutrients like nitrogen to build up.

Burying carcasses can also be compared to sending rubbish to the tip. Breakdown will be slow, and no useful end product is created.

A more useful option

An alternative option is to “recycle” carcasses by composting them. Composting can accelerate the decomposition of animal tissues and is environmentally friendly, capturing nutrients.




Read more:
Animal response to a bushfire is astounding. These are the tricks they use to survive


Composting kills most pathogens, whereas burial just moves the problem underground. It also suppresses smelly odours and doesn’t attract scavengers. The usable organic material resulting from the composting can also be applied to nutrient-poor soil.

Getting used to the ‘yuck’ factor of carcasses.

Composting can be time-consuming and hard to get right. It requires careful monitoring of temperature and moisture content to ensure all disease-causing pathogens are killed, and odours are suppressed.

There’s also a “yuck” factor and the public would probably need convincing for the method to be widely adopted.

But whatever option we choose, it’s clear there’s more we can do with carcasses than simply burying them.The Conversation

Emma Spencer, Ph.D. student, University of Sydney; Chris Dickman, Professor in Terrestrial Ecology, University of Sydney; Philip Barton, Honorary Senior Lecturer, Fenner School of Environment and Society, Australian National University, and Thomas Newsome, Lecturer, University of Sydney

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

Media Release: Dead Shearwaters In NSW


The link below is to a media release concerning the many dead Shearwaters being found on the coast of NSW, Australia.

For more visit:
http://www.environment.nsw.gov.au/media/OEHmedia13112101.htm

South Africa: Kruger National Park – Poachers Shot Dead


The link below is to an article reporting on the deaths of three Rhino poachers in South Africa.

For more visit:
http://www.reuters.com/article/2013/03/28/us-safrica-rhino-poachers-idUSBRE92R09J20130328

Mount Everest to be Given a Clean Up


The world’s highest mountain, Mount Everest, is to be given a clean up. Everest, which was first climbed by Edmund Hillary in 1953, has become something of a garbage tip. Everything from climbers rubbish to dead bodies has been left on the mountain. Now a Nepalese expedition made up of twenty Sherpa mountaineers and eleven support crew is seeking to remove some of the garbage left behind since that first ascent.

The government of Nepal wants to clean up the popular tourist attraction, bringing down rubbish that includes old tents, climbing equipment and the odd body. Global warming has led to much of the rubbish (and several bodies) no longer being covered by snow and ice.

Over 300 people have been killed attempting the climb to the top of the world, the Mount Everest summit.

For more on this story, see the Reuters article at:

http://af.reuters.com/article/worldNews/idAFTRE63I0XE20100419

AUSTRALIA: TRAGEDY IN THE OUTBACK – Man Found Dead in the Kimberley


A man thought to be from Queensland has been found dead in the Australian outback. The body was found in Western Australia’s Kimberley region, in the far north of the state on the Meda cattle station, about 40km west of Derby.

Near the body was the man’s desperate plea for assistance with the word ‘help’ written in the dirt. He had constructed a shelter and his water bottle was empty. No vehicle has yet been found.

The man was some 15km from the Meda cattle station homestead on the 1.25 million acre property.

The temperatures in this region had reached 40C last week. The man is thought to have died a few days ago.