Austral amphibians: Gondwanan relicts in peril

Abstract

Over 30% of Australasian amphibians are currently threatened with extinction. While habitat loss, introduced species and disease have been identified as major threats, the impacts of climate change are understudied. Threatened frogs fall into distinct biogeographical and ecological groupings that can be linked to specific threats (e.g. mountain- top endemics and climate change; stream-dwelling wet forest frogs and disease; and small island endemics and feral pests). The impacts of gradual climate change over millions of years has isolated specific species into climatic refugia (resulting in restricted geographic ranges), which combined with the ecological traits of these species (e.g. small clutch-size) dramatically increases extinction risk. Australasian frogs demonstrate intrinsic links between biogeographic history, species ecology and conservation status. The solutions to most threats are clear at a broad level, stop land clearing, reduce CO2 emissions and control feral animals; however, declines linked to the disease chytridiomycosis are not easily resolved. Chytridiomycosis is not a universal threat and understanding the causes of variation in impact is critically important. While the threats of land clearing, disease and introduced species are regional and/or species specific, the impacts of climate change must be examined carefully as all species are likely to affected. Here we cover these issues for Australasian frogs, presenting regional examples that highlight threats and avenues for future research and management.