A University of Wollongong-led research team has released 115 southern corroboree frogs into a remote part of Kosciusko National Park.
Prior to the release there were, by some estimates, as few as 50 adult southern corroboree frogs left in the wild.
Without human intervention, it is possible the critically endangered species will soon become extinct.
The UOW researchers are working with the Taronga Conservation Society, Zoos Victoria and the NSW Department of Planning, Industry and Environment (DPIE) on the project.
The released frogs were reared at UOW and provided a special diet of carotenoids.
Associate Professor Phillip Byrne and Dr Aimee Silla from UOW's Evolution and Assisted Reproduction Laboratory are leading the project.
They are working with UOW carotenoid function expert Senior Professor Sharon Robinson, Taronga Zoo's Herpetofauna department head Michael McFadden, DPIE's Threatened Species Officer Dr David Hunter, and Deakin University's Professor John Endler, a world leader in evolutionary biology.
"By manipulating diet we may be able to improve a frog's prospects of survival and reproductive success once released back into the wild," Professor Byrne said.
"In captivity, carotenoids improve colouration, exercise performance, the diversity of beneficial microbes on the skin, and recovery from hibernation, all of which should help their prospects of survival."
The team used a helicopter to access a secret location in a remote area of the national park, surrounded by impenetrable scrub.
They released the frogs into several large (8m diameter) ring enclosures, custom-built by DPIE.
"The frogs were transported in large containers, then individually released so that their exploration behaviour could be video recorded and later quantified using sophisticated behavioural analysis software," Prof Byrne said.
"We have previously shown that corroboree frogs have personality along the exploration axis, so we expect that some frogs will explore their new environment more rapidly than others."
The survival and viability of frogs will be monitored every few months for the next few years.
The researchers will also monitor whether the frogs are breeding successfully.
If successful, the program could benefit endangered frog species worldwide.
"The concept of manipulating micronutrients in the captive diet to improve post-release survival and performance could be applied to threatened frog species worldwide," he said.