Communities on the front line during a frog conservation emergency

We need your help to report any sick or dead frogs this winter.

During the 2021 winter, frogs across eastern Australia experienced a mass mortality event. We were able to understand the scale of this terrible pattern thanks to citizen scientists across the country reporting on frogs in their local areas.

The continued reports from FrogID followers has enabled us to ascertain that the mass mortality event hasn’t happened to the same degree since. While we continue to investigate the cause and impact of these frog deaths, we need your help again this winter to report any sick or dead frogs.

My story

I arrived in Australia in May 2022 to begin a postgraduate research project with Dr. Jodi Rowley at the Australian Museum and UNSW Sydney. My interest in Australian frogs was piqued during the Black Summer bushfires of 2019/2020. I wanted to understand how frogs were responding to the astonishing intensity of these burns. Back home in the U.S., we were having massive wildfires around the same time. When I arrived here in Australia, though, as happens so often in research, I was forced to consider another threat to frogs.

Frogs and floods

If you were in eastern Australia and remember 2022, you remember rain – lots of it! It seemed like the entire winter was one flood warning after another, with much of NSW facing evacuation notices. Lismore and other towns were devastated. At the same time, reports of dead and dying frogs began coming into the Australian Museum FrogID inbox once again. Part of my job was to drive around NSW to pick up the dead frogs. I was shocked when one woman presented us with a tupperware container with over 30 dead tree frogs, all collected from around her garden. This wave of frog death, although nowhere near that of the previous year, was frustrating to say the least.

Just the previous winter in 2021, the death toll was much worse, with over 1600 reports of sick or dead frogs. The winter of 2021 was also characterised by heavy, La Niña-associated rainfall and subsequent flooding.

Frogs and fungus

We were desperate to determine the cause of this mysterious frog die-off. The obvious suspect was the amphibian chytrid fungus (Batrachochytrium dendrobatidis), which has been the suspected culprit in the decline of hundreds of frog species around the world, and has been in Australia since at least 1978. It seemed notable that the majority of these frog deaths corresponded with La Niña’s heavy rainfall and flooding. Maybe the two threats were somehow connected? Afterall, the amphibian chytrid is a fungal pathogen that thrives in cool, damp conditions exactly like those experienced in 2021 and 2022.

Finding the answer

At the Australian Museum, we got to work. We appealed to members of the public to continue reporting dead frogs. We furiously tested the dead frogs for the amphibian chytrid fungus while working with our partners at Taronga’s Australian Registry of Wildlife Health and other universities, government biosecurity and environment agencies. The majority of the dead frogs tested positive for the chytrid fungus, with many showing a high fungal load. So, the amphibian chytrid fungus was probably a piece of the puzzle, but a substantial proportion of the dead frogs tested negative. This led us to suspect there was something else at play.

A recent study may have helped shed more light on this question. In a paper published this year, the authors showed that 36% of screened frogs from the mortality event had at least one pesticide present in their livers, including rodenticides (AKA rat and mouse poison). Although this isn’t thought to be the main driver of frog deaths, it’s worrying.

Call to action

To answer these questions, we urgently need your help. If this winter continues on the same trend, eastern Australia could be in for more extreme weather. To help us monitor the health of our frogs and detect and respond to any mass mortality of frogs (should it occur), please keep a lookout for any sick or dead frogs and report them. Signs of a sick frog include lethargy, lying out in the open during the day, and discoloured skin. If you see a sick frog, please take a photograph and send the photo and your location to the Australian Museum’s citizen science project FrogID via calls@frogid.net.au.

Please consider donating to help support our ongoing investigation into the cause and scale of this mass mortality event and our monitoring of frog populations. Please also download the free FrogID app and record calling frogs whenever you can, as these recordings are extremely valuable for ongoing frog conservation research.

For as depressing as freezers full of dead frogs can be, we were strangely inspired over the past few winters. We watched people go to great lengths to help us uncover the reason Australian frogs were dying, because they truly cared. Over and over again, we heard observant farmers, gardeners, and homeowners recount memories of foregone times when singing frogs were everywhere. If we want a frog-filled future, we’re going to need people who care and notice. Thank you for being those people.

Eli Bieri, Research Assistant & Masters student, Australian Museum Research Institute & UNSW Sydney

Acknowledgements

Thank you to everyone who has reported sick and dead frogs, stored dead frogs in their freezer, or transported them to National Park depots and veterinarians, our research couldn’t happen without your help. We are also extremely grateful to everyone who has donated money or their time by recording frogs using the FrogID app. It has greatly improved our understanding of how frogs respond to fires, floods, droughts, and disease. Finally, thank you to the Australian Museum Herpetology Team, Taronga’s Australian Registry of Wildlife Health and all our collaborators across the country.