Record Release of 842 Critically Endangered Corroboree Frogs in NSW

Bred and raised at Taronga Zoo Sydney, the frogs were released in partnership with the NSW Government’s Saving Our Species program and the NSW National Parks and Wildlife Service as part of long-term efforts to strengthen the fragile wild population, estimated to number fewer than 2000 mature individuals.

Weighing just 2–3 grams and no bigger than a paper clip, these vividly striped amphibians have an outsized impact on Australia’s subalpine ecosystems. By feeding on small invertebrates, they help keep insect communities in balance, and their role in subalpine woodlands makes them sensitive indicators of environmental change.

This year’s larger release reflects new conservation science findings showing that releasing bigger, genetically varied groups of frogs dramatically improves the species’ survival prospects.

“This is the largest Taronga-bred Northern Corroboree Frog release ever undertaken for this critically endangered species. We’ve learnt over the years of breeding and releasing and from scientific literature that releasing larger cohorts helps boost population success because more frogs survive early life challenges such as variable weather and disease,” said Michael McFadden, Wildlife Conservation Officer at Taronga Conservation Society Australia.

This approach also preserves stronger genetic diversity, making the population more resilient to long term threats like chytrid fungus. With more individuals reaching maturity, the chances of establishing stable breeding groups in the wild increase significantly. Additionally, natural calling behaviour becomes more robust, with stronger breeding choruses that help attract females and stimulate successful reproduction.

Northern Corroboree Frogs are found only within the Brindabella and Fiery Ranges in NSW and the ACT at elevations between 750 and 1800 metres above sea level. IMAGE

“The biggest threats to this endemic species include chytrid fungus, invasive species such as pigs and deer, and extreme climate events, including the Black Summer bushfires which devastated large parts of their habitat,” said Dave Hunter, Senior Threatened Species Officer with the Saving Our Species Program.

“We have both the tools and the knowledge to prevent this species from disappearing forever and these large scale releases are a crucial part of that effort.”

Coordinated by the NSW Government’s Saving our Species program and delivered in collaboration with Taronga Conservation Society Australia, the conservation breeding program has released thousands of eggs and hundreds of frogs, with more releases planned in the coming years to secure the survival of this unique Australian amphibian.

A Northern Corroboree Frog insurance breeding population was established at Taronga Zoo Sydney in 2010 and houses 370 adult frogs. Since the first release in 2011, a total of 2604 Taronga-bred eggs and tadpoles and 1098 frogs have been released back to the wild.