Frog ‘Saunas’ – Pandemic Protection for Endangered Frogs Facing a Deadly Global Fungus

A study by Macquarie University and the University of Melbourne has found that heating shelters can help frogs combat chytridiomycosis effectively. This method, which allows frogs to ‘bake off’ infections, could significantly lower mortality rates and increase resistance to future infections, providing a viable conservation strategy for endangered amphibians.

Researchers have developed a groundbreaking method using heat to combat chytridiomycosis in frogs.

This simple strategy involves creating ‘hotspot’ shelters where frogs can elevate their body temperatures to kill off fungal infections. The study shows promise for not only reducing mortality but also enhancing immunity against future infections, offering a scalable and cost-effective solution for amphibian conservation.

Frog ‘Saunas’ a Lifeline for Endangered Frog Populations

Researchers at Macquarie University have discovered a straightforward and efficient heat-based method to aid endangered frogs in withstanding the devastating impacts of a pandemic affecting multiple species.

Working alongside the University of Melbourne, the team focused on combating chytridiomycosis, a fungal disease that has led to the extinction of at least six amphibian species in Australia and poses a threat to dozens more worldwide.

Green and gold bell frogs in artificial hotspot shelter. Credit: Anthony Waddle

Significant Breakthrough in Amphibian Conservation

The findings, published today (June 26) in the journal Nature, offer a potential lifeline for fast-declining populations like the green and golden bell frog (Litoria aurea), which has disappeared from more than 90 percent of its former native range in Australia.

Dr. Anthony Waddle, a Schmidt Science Fellow at Macquarie University’s Applied BioSciences and lead author of the study, says very few interventions address the impacts of the international spread of the disease-causing chytrid fungus (Batrachochytrium dendrobatidis or Bd).

“In the 25 years since chytrid was identified as a major cause of the global collapse of amphibian populations, our results are the first to provide a simple, inexpensive, and widely applicable strategy to buffer frogs against this disease,” Dr. Waddle says.

Dr. Anthony Waddle with frog. Macquarie University

Developing Practical Solutions for Chytridiomycosis

Chytridiomycosis (chytrid) typically establishes itself permanently once it spreads to a new environment and has caused greater damage to global biodiversity than any other recorded disease or invasive species.

Of chytrid-stricken species worldwide, 90 have gone extinct or are presumed extinct in the wild. Another 124 species have declined in number by more than 90 percent.

Senior author Professor Rick Shine, from Macquarie University’s School of Natural Sciences says this study has demonstrated a simple intervention that can easily scale up, potentially helping reduce the impact of the deadly chytrid pandemic.

“Chytrid isn’t going away, but our behavioral ecology intervention can help endangered amphibians co-exist with chytridiomycosis in their ecosystems,” Professor Shine says.

Practical Implementation and Future Prospects

The research team found artificial ‘hotspot’ shelters built from readily available materials, such as bricks and PVC greenhouses, can allow frogs to quickly ‘bake off’ infections with the chytrid fungus.

When frogs shifted to hotspot shelters, chytrid infections were reduced significantly.
“The whole thing is like a mini med spa for frogs,” says Dr. Waddle.

“In these simple little hotspots, frogs can go and heat up their bodies to a temperature that destroys the infections.

The study also showed that frogs who survive a chytrid infection can develop a form of acquired immunity, making them more resistant to future infections.

“Lowering mortality rates and boosting their immunity to chytrid is the key to protecting amphibians from this disease, which is now endemic around the world,” says Dr. Waddle.

Dr. Waddle says these simple ‘hotspot’ shelters are easy to reproduce, and the strategy can easily be scaled up with community involvement.

Professor Lee Skerratt, Professorial Fellow in Wildlife Bioscience at the University of Melbourne, says: “This research has great potential to be extrapolated to other endangered frog species threatened by chytridiomycosis, and demonstrates the value of cross-disciplinary and cross-institutional collaboration in tackling this global problem.”

Reference: “Hotspot shelters stimulate frog resistance to chytridiomycosis” 26 June 2024, Nature.
DOI: 10.1038/s41586-024-07582-y