It was the sound researchers had waited years to hear – the “waaah, waaah, rah, rah, rah” of the Southern Bell Frog.
The endangered amphibian was heard calling at ‘The Ville’, a property 5kms from Corrong, on the Lower Lachlan River, in October 2013.
Environmental flows had triggered the remarkable response.
While not seen, researchers were able to record the distinctive call, confirming that the frog had returned.
Senior Wetlands and River Conservation Officer Paul Packard said the discovery was tremendously exciting.
“This response reinforces the position that with careful and well-planned use of environmental water we can assist the recovery of this population,” Mr Packard said.
“With the big floods of 2012 the Southern Bell Frog was detected in Lake Bullogal – a lake that had been dry for more than 20 years.
“Before that, they hadn’t been seen or heard in the Lachlan catchment since 1978.
“In an effort to consolidate the positive effects of the 2012 floods, an environmental flow of 90,000 megalitres was released into the Lower Lachlan River over the winter of 2013.
“As a result of this flow, the frogs were heard calling at ‘The Ville’ soon after,” he said.
The Southern Bell Frog is relatively long-lived – about four years – but can’t live or breed without water. It’s thought that the frogs survived unnoticed for many years in farm dams and billabongs in the Lachlan catchment.
The OEH has funded researchers from Charles Sturt University to undertake surveys to establish the range and number of frogs present.
“We plan to repeat our monitoring and conduct specific, event-based surveys when applying environmental water in the area,” Mr Packard said.
“We are also going to continue our efforts searching for the Southern Bell Frog in other areas of the catchment using audio recording equipment to capture their calls.
“There are dozens of similar billabongs that could provide ideal habitat for the Southern Bell Frog.
“With further environmental flows we may be able to encourage existing populations to recover and repopulate the catchment,” he said.
The Lachlan community continues to play an important role in the recovery of the Southern Bell Frog.
“The excitement and enthusiasm of the Lachlan catchment community is one of our greatest resources,” he said.
“Landholders are in an ideal position to provide valuable intelligence on the presence of the Southern Bell Frog on their properties and we are keen to hear from anyone who thinks they may have Southern Bell Frogs on their land,” Mr Packard said.
The Southern Bell Frog (Litoria raniformis) is classed as endangered in NSW and vulnerable nationally.
The frog is one of the largest species in Australia reaching up to 104mm in length. Their colouring ranges from bright green to dull olive with brown or golden marbling. The back is warty with a pale green stripe down the middle. The groin and thighs are usually blue with or without a few small pale yellow spots.
The frogs are generally found in vegetation along the edges of permanent or semi-permanent water. They are most active at night, especially on warm nights, after rain when they are more likely to be heard calling.
The Southern Bell Frog feeds on a range of insects, water snails, small fish, tadpoles and other frogs (even juvenile members of the same species).
Their tadpoles grow to about 10 centimetres long, and take anywhere from two months to one-and-a-half years to fully develop.