A deadly fungus has wiped out 90 amphibian species and infected hundreds more over the past 25 years. But in eastern Australia, one biologist just proved that a surprisingly simple fix works: tiny heated shelters that let frogs warm their bodies enough to fight off the infection.
Dr. Anthony Waddle, a researcher at Macquarie University, built what he calls "frog saunas"—masonry bricks with frog-sized holes and small PVC greenhouses that create warm microclimates. The logic is straightforward. Chytridiomycosis, the fungal disease in question, thrives in cool conditions. When frogs can access these heated spots, especially during vulnerable winter months, their body temperature rises enough to clear the infection. More importantly, once recovered, they develop resistance that holds even when temperatures drop again.
The green and golden bell frog became his test case. This species, once common across eastern Australia—living in letterboxes and backyards—has lost more than 90% of its native range since chytridiomycosis arrived in 1978. Waddle's saunas helped reverse that trajectory. When he published his results in Nature in 2024, it marked the first time anyone had demonstrated a simple, inexpensive strategy that actually works in the field.
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Start Your News Detox"In the 25 years since chytridiomycosis was identified," Waddle said, "our results are the first to provide a widely applicable strategy to buffer frogs against this disease."
But Waddle knows heated shelters alone won't save the species long-term. Over the past year, he's vaccinated hundreds of green and golden bell frogs—likely the largest population boost that species has seen in a decade—and plans to release them back into the wild. He's also opened two "frog hospitals" in Greater Sydney to care for frogs awaiting vaccination before winter outbreaks, and he's delivering vaccinations across Australia's east coast.
His work earned him the 2025 Future for Nature award, which he's using to expand these efforts. Beyond vaccines, Waddle is now investigating genetic mechanisms that could provide permanent resistance to chytrid, essentially future-proofing the species against this threat and potentially others like it.
What started as a creative solution to a seasonal problem has become a multi-pronged conservation strategy. The frog saunas remain the accessible piece—something communities can actually build and maintain. The vaccines and genetic research are the longer play. Together, they suggest that even in the face of a global amphibian collapse, there's a path forward.
