More than 800 tiny, technicoloured northern corroboree frogs have been released into the wild in the Brindabella National Park in southern NSW to try to bolster the numbers of one of Australia's most critically endangered amphibians.

Weighing just 2–3 grams and no bigger than a paper clip, the 842 frogs were born and bred at Sydney's Taronga Zoo in a special quarantine facility designed to keep out a deadly fungus that had driven the species to the brink of extinction.