The southern corroboree frog is Australia’s most endangered frog. Scientists have not discovered a reason for the reduction in frog numbers. There are a range of problems that affect the area that they live in. Increased access by people with four-wheel drive vehicles and the development of ski resorts are destroying their habitat. Global warming is also a big problem for them, because they are used to the cold. Global warming may shorten the frog's breeding time during winter, and also destroy their snowy habitat. Holes in the ozone layer may also be a problem, because when there are holes in the ozone it means that more sun rays hit the ground, and so there is less snow. Disease from funguses can kill lots of the frogs. Erosion and pollution of waterways in which they breed can kill the frogs' eggs. They are also affected by wild pigs which destroy the wetlands.