Scientists Return Frogs to Australia After 40-Year Extinction

After 40 years of silence, the croaks of green and golden bell frogs are returning to Canberra's wetlands.

Scientists released 25 green and golden bell frogs at Mawson Ponds on Tuesday, marking the species' first return to the Australian Capital Territory since they vanished around 1981. The culprit was chytrid fungal disease, one of the deadliest threats amphibians have ever faced.

The frogs didn't come back without backup. Each of the 25 pioneers has been immunized against the disease and microchipped for tracking.

But the real innovation lies in what researchers built to welcome them home. The team installed 60 "frog spas" and 180 "frog saunas" across 15 wetland sites around Canberra.

The saunas are perspex pyramids covering black-painted bricks that heat up naturally in the sun. On cold 10-degree days, they still reach temperatures in the high 20s, hot enough to kill the chytrid fungus but perfect for frogs who prefer lounging at 30 degrees Celsius.

The spas are satellite ponds with slightly salty water. Just three parts per thousand salt concentration stops the fungus while keeping frogs completely comfortable.

Associate Professor Simon Clulow from the University of Canberra led the project. "It feels quite incredible and really significant to return this species back to this region for the first time in almost 50 years," he said.

The team gave each frog a name with help from volunteers. Meet James Pond and Dua Leaper, two of the brave pioneers heading into the wild.

The Ripple Effect

This release is just the beginning of something bigger. Over the coming months, researchers will release about 375 frogs total across all 15 sites.

The goal is 200 frogs at each location, and the math looks promising. One female can lay up to 8,000 eggs, meaning populations could explode quickly if the saunas and spas do their job protecting the next generation.

These frogs once thrived along Australia's entire east coast. Now they're endangered in New South Wales, surviving only in isolated pockets, often near slightly saltier water.

Dr. Jarrod Sopniewski, a postdoctoral fellow working on the project, compared the release to watching children leave home. "A bit daunting, but overwhelmingly exciting," he said.

The chytrid fungus has devastated amphibians globally, wiping out 90 species in 50 years. But this project shows that creative science can turn the tide, one heated brick and salty pond at a time.

The frogs are home, and they've got the facilities to thrive.