20240123 202821The dusk light is fading and a small group, gathered at the edges of a wetland,   switch their spotlights on and cast beams across scattered grasses and ponds. The February night is warm and still – perfect for spotting frogs. The group, three surveyors from Merri Creek Management Committee and Merri-bek Council, are scouring a new wetland at Moomba Park, Fawkner, for the presence of the Growling Grass Frog,which until recently, hasn’t been seen locally for over 50 years.

The Growling Grass Frog is a ground-dwelling tree frog that was once abundant along the Merri Creek, but whose calls went largely unheard in the area in the 1970s. The species is now listed at both state and federal levels as vulnerable, having disappeared entirely from some areas, including the extent of the Australian Capital Territory. In 2019 however, Merri Creek residents were thrilled to report the distinctive call was being heard locally once more.


“Until recently, we thought the frogs were getting washed down from further upstream,” says Michael Longmore, who heads up the Ecological Restoration Team at Merri Creek Management Committee.

“But once we studied the area, we were hopeful there could be an evolving frog population. We wondered whether incorporating frog habitat into existing plans for a stormwater treatment plant could work – and Merri-bek Council were quick to get on board, even though the prospect of the frogs using the wetland was considered a long shot.”

Collaboration along our precious creekGrowling Grass Frog metamorph by G Heard

The wetland where Michael and his fellow surveyors now stand (completed in July 2023) is the result of Merri Creek locals, Merri-bek Council, Melbourne Water and Merri Creek Management Committee collaborating to ensure the Growling Grass Frog’s call will still be heard here in another 50 years. The pond’s success as habitat will be an important marker in the frog’s struggle for survival. And tonight, the stakes are high – a survey in November 2023 found no frogs; in January 2024 a second survey found just one. The team hopes the extra month might have given the frogs a chance to settle in.

Michael plays pre-recorded audio of the famous, guttural Growling Grass Frog call, which has been likened to the sound of a chainsaw. The team waits in silence for a response. After five minutes, the torches are turned back on. Michael’s teammate Nico Wayland stops and backtracks to a spot at the grassy edge of a pond, then takes a step closer.

Sitting atop stands of Common Spikerush (carefully selected by wetland designers for this purpose), is a pair of adult Growling Grass Frogs. And the news gets better: a closer inspection reveals the frogs are proud new parents. In the grasses and on the ground nearby, first one and then another tiny frog is seen. The final count is 18 soon-to-be-adult frogs.

It’s the news that Merri Creek supporters have been hoping for. In 2023, seventy-three generous donors were so inspired by our shared hopes of hearing the calls of the Growling Grass Frog here again that they donated nearly $20,000 to the Merri Creek Environment Fund towards research, surveys, community engagement and citizen science.

The Growing Grass Frog life cycle

The “baby frogs” that Nico and the team are seeing are known as metamorphlings. These are frogs in the third stage of a frog’s four-stage life cycle, with the first and second stages being eggs and tadpoles, and the final stage being fully formed adults. Metamorphlings have lost their tails and have fully formed legs but are not yet old enough to breed.
Nico is excited to see such a quick response to a management intervention.

“With most ecological restoration work it can take many years to see much result from your efforts. But this time, the frogs appeared pretty quickly after the wetland construction. We’re thrilled!”

Michael Longmore agrees.

“The frogs still have a long way to go – and it’s important that we keep surveying – but this is an early sign that the efforts Merri-bek Council made to consult experts about what the Growling Grass Frog needs to thrive, was worth it. We hope to share more stories of success with our donors, who helped to deepen our understanding of this precious frog by supporting our campaign last year.”

Thankyou

We thank the generous donors who supported our Merri Creek Environment Fund Autumn 2023 appeal to Help our endangered Growling Grass Frog. These donations will continue to provide information about how we can best support these precious frogs to thrive in the Merri Parklands.

Want to help land managers learn more about the Growling Grass Frog? Download Melbourne Water's frog census app. You can play an important role in helping to capture frog data at local creeks, rivers and wetlands.