[Animals] Hopes high as hundreds of critically endangered frogs survive release into wild in Victoria

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Hundreds of captive-bred, critically endangered frogs are managing to survive after being released at a fast-flowing mountain stream near Mount Beauty in Victoria, with some moving a “considerable distance” from the release point.

More than 600 spotted tree frogs have joined dwindling wild po[CENSORED]tions in the Kiewa River, as part of a Zoos Victoria conservation breeding program to boost numbers and genetic diversity after 50% of the frog’s Victorian habitat was severely burnt in the 2019-20 black summer bushfires.

This year a team of biologists from Zoos Victoria and Wild Research released 265 one-year-old frogs, following a 2024 cohort of 300 tadpoles and 70 juvenile frogs.

So far more than half of the animals released have been found again, according to the Wild Research director, Dr Matt West, who has been part of a team tracking their survival after release.

“Quite a large proportion of those animals are actually surviving, which is exciting and brings us a huge amount of hope that we might be able to recover this po[CENSORED]tion of spotted tree frogs.”

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It was promising news for a species facing numerous threats, including a disease called the chytrid fungus, predation by introduced fish species such as trout, as well as flash flooding and bushfire.

Even though the frogs were individually marked (with a skin clip on their toe), finding them again could be challenging, West said. Spotted tree frogs grew to about 6cm long and were well camouflaged with their vivid green spotty skin.

“They are very difficult animals to find because they look very similar to the types of things they like to sit on – granite boulders, ferns and sedges,” he said.

The task of finding them was made even more difficult after many of the captive-bred animals had moved “a considerable distance” – about a kilometre in a year – from the section of stream where they were released, West said.

“It’s challenging walking up and down the stream, just for a couple of kilometres. But when you’ve got to extend that out to 10km, it makes it even more difficult to find a frog.”

 

https://www.theguardian.com/environment/2025/jul/22/critically-endangered-spotted-tree-frogs-survive-release-into-wild-victoria