A second batch of southern corroboree frogs has been released in Kosciuszko National Park as part of continued efforts to boost numbers of the endangered species since the Black Summer bushfires.
One hundred captive-bred frogs were released in the park this week after 100 were released in March last year.
The NSW Department of Planning and Environment's senior threatened species officer, Dave Hunter, said without this conservation program the frogs would become extinct.
"Outside of our work, as far as we know, there are no southern corroboree frogs remaining," Dr Hunter said.
"I'm part of a community with a common goal of looking after this incredible species."
The southern corroboree frog has been under threat since the late 1990s.
It is listed as critically endangered due to a fatal disease caused by chytrid fungus, but is also impacted by feral animals and climate change.
The captive-bred frogs have been released into five "disease-free" enclosures in the park since 2013, to specifically protect them from various threats.
The enclosures were heavily impacted by the 2019–2020 Black Summer bushfires, but have since been redesigned with fire suppression sprinklers.
Settling in just fine
Last year's cohort of frogs, which have been using the enclosures for the past 12 months, are apparently "thriving".
"They've settled in just fine, and they're feeding and surviving well and looking robust," Dr Hunter said.
"They've really got used to the idea that they're back in the wild and they slip into their normal regime of calling and breeding."
It is due to this success that the second lot of 100 frogs have been introduced to the enclosures this week.
Dr Hunter said eggs and young frogs born within the enclosures had the potential to be released directly into the wild, in the hope they eventually developed a resistance to threats, namely the deadly fungus.
"We still have southern corroboree frogs persisting in the wild outside of the enclosures," he said.
"The survivorship we get for animals we put directly into the wild is not that great, hence why we're also using the enclosures.
"Ultimately our hope is the frogs have a stronger resistance or resilience to the fungus and we can also have them thriving and doing well in the wild."
A team effort
The frogs released were bred at Taronga Conservation Society and Melbourne Zoo's Amphibian Bushfire Recovery Centre.
"We are incredibly proud to be able to collaborate with our conservation partners and together provide a new cohort of captive-bred frogs for release into disease-free field enclosures," said Alex Mitchell, life sciences manager for herpetology and native mammals at Melbourne Zoo.
"It's an import step towards the conservation recovery of this species."
Dr Hunter has also credited the Walgalu Wiradjuri community from the Brungle and Tumut region for their involvement in the project.
"It's a culturally significant species," he said.
"It's important for us to work with First Nations people to ensure the persistence of this species so the cultural connection can be maintained."
