Scientists have brought back green and golden bell frogs to the Australian Capital Territory (ACT) after nearly 40 years. The first group of 25 frogs was released on Tuesday at Mawson Ponds. This marks a major step for saving these frogs, whose numbers fell sharply due to the chytrid fungal disease that destroyed 90 amphibian species in 50 years. Associate Professor Simon Clulow from the University of Canberra said it was "quite incredible and really significant to return [the species] back to this region for the first time in almost 50 years." The frogs, about 14 months old, have been immunised against chytridiomycosis, the disease caused by fungi. This is the first of 15 planned releases around Canberra, totaling around 375 frogs. Each frog is microchipped and has a name given by volunteers. Dr Jarrod Sopniewski joked about fun names like “James Pond” and “Dua Leaper.” To help the frogs survive, the team built 60 "frog spas" — small ponds with a bit more salty water that reduces fungal growth. They also installed 180 "frog saunas," which are clear pyramid shelters that warm the frogs to temperatures that kill the fungus. Clulow explained the fungus hates temperatures above 25°C, while the frogs prefer around 30°C. These steps create safe spots for baby frogs, which are not immunised. The green and golden bell frog is endangered in New South Wales and grows up to 8.5 cm long, living near the ground. The scientists hope each site will have 200 frogs. Sopniewski said, "One female can have up to 8,000 eggs, so their population growth should start really rapidly if our interventions against chytrid are helping those initial founders survive and reproduce." He added, "It’s almost like letting your children go out into the world themselves. A bit daunting, but overwhelmingly exciting."