decline The main threats to the survival of the frogs are thought to be infection with the chytrid fungus and bushfires. Severe bushfires in the Victorian and NSW high country in January 2003 destroyed much of the frogs' remaining habitat, especially the breeding sites and the leaf litter that insulates overwintering adults. The fire affected almost all southern corroboree frog habitat, although later surveys showed that the fire resulted in a lower than expected decline in population.} The 2019–2020 bushfires in Australia destroyed a significant portion of Kosciusko National Park, and killed two-thirds of the southern corroboree frogs contained in specially designed disease-free enclosures built by conservationists. Other threats to the southern species include residential and commercial development (including ski resorts); climate change (causing drought and fires); and pollution. Other causes such as habitat destruction from recreational 4WD use; feral animals; degradation of the frogs' habitat; and increased UV radiation flowing from ozone layer depletion. The drought affects these frogs by drying out their breeding sites so that the breeding cycle, which is triggered by seasonal changes and may require moistening of the bogs in autumn and spring to bring on specific developmental events, is delayed. This may mean that tadpoles have not metamorphosed by late summer when their bogs dry out, and so perish. Conservation efforts The Amphibian Research Centre had already begun a rescue programme under which eggs were collected and raised to late tadpole stage before return as close as possible to their collection site. Research is now under way into captive breeding and on which life cycle stage – eggs, tadpoles or adults – promises the best chance of survival following return to the wild. The national parks authorities in the ACT, NSW and Victoria have developed conservation programmes, including a captive husbandry programme at Tidbinbilla, ACT; Taronga Zoo in Sydney; and at Healesville Sanctuary, by Zoos Victoria. Conservationists have stepped up efforts to increase the population of the southern corroboree frog since the 2019–20 bushfires. In March 2022, 100 frogs were released into the park as part of a joint breeding program between Taronga Zoo, Zoos Victoria, the NSW National Parks and Wildlife Service and the NSW Government's "Saving our Species" program. At this time there are five enclosures for the frogs, with the newest one built to better withstand the effect of fire. References External links Southern Corroboree Frog (Frogs of Australia) Southern corroboree