The growling grass frog (growler) has returned to a Merri Creek swamp after a successful habitat restoration trial.
The five-month long trial conducted by Melbourne Water brought the site back to life by mimicking the growler’s natural habitat.
Australian National University and Queensland University ecologist Dr Geoffrey Heard said the frog population return is brilliant.
“To my knowledge, this is the first addition to the frog population in this wetland in 25 years,” he said.
The trial to revitalise the Merri Creek habitat was funded by the Victorian government’s Melbourne strategic assessment (MSA) program that works to protect nature and native species.
MSA growling grass frog program coordinator Dr Zoe Squires said she saw hundreds of growlers actively foraging in this new habitat.
According to Melbourne Water, more than 160 growlers were detected in one night at the location which has been kept confidential to protect the frogs.
“The ecosystem has come alive and now supports a wide range of additional species,” Dr Squires said.
Between October 2024 and March 2025, 10 million litres of water were introduced into the swamp, re-establishing the vegetation that supports frog breeding.
Adjacent, large, woody weeds were also removed to expose the frogs to more sunlight.
Freshwater ecologist and waterwatch coordinator at Melbourne Water Jane Petch said she was stunned by the frog’s quick migration.
“It was thrilling to see how quickly the growlers have moved in and made the most of their new home,” she said.
According to Melbourne Water, it will eventually manage about 90 dedicated growler habitats under the MSA program.
Dr Heard said active management of these habitats is what growling grass frog populations need to survive.
Growling grass frogs were once widespread across south-eastern Australia, and had retreated due to urbanisation, disease and drought.
The frogs got their name from their unique growl-like call.
If you hear the call of a growler, you can record the sound on the Melbourne Water Frog Census app which will be reviewed by an ecologist.
