A project undertaken at The University of Western Australia, and supervised by A/Prof Nicola Mitchell.
Frogs are the most globally threatened group of vertebrates, with over a third of species at risk of extinction. Western Australia is something of an anomaly, hosting around 83 frog species but with only three species (~4%) being listed as threatened. All three threatened frog species in Western Australia have a restricted distribution in the biodiverse southwest. The biology and conservation needs of two species from Margaret River are well understood, but the third species, the Sunset Frog – restricted to peatland habitats in the Walpole Wilderness – is comparatively a mystery.
The sunset frog (Spicospina flammocaerulea) is one of Western Australia’s most ancient frog species, estimated to be over 30 million years old. It was discovered in peatlands in the mid-1990s, and owes its common name to an unmistakable fiery orange and blue belly and purple-hued glands on its back. Monitoring data have revealed a steep decline in the number of calling males over the last decade, but the causes are unclear. Fire, climate change and feral pigs are recognised threats to their peatland habitats, which were recently listed as an Endangered Threatened Ecological Community. In addition to changes to their habitats, another potential cause of decline is chytrid fungus—a disease that devastated frog communities in eastern Australia and led to extinctions of seven species.
This project will provide urgent information to aid the conservation of sunset frogs, which serve as an umbrella species for conservation of their peatland ecosystem. Our four goals are to: 1) Develop optimal and repeatable survey methods for detecting sunset frogs; 2) Identify the current status of sunset frog populations across their known and projected range; 3) Characterise the habitat and environmental requirements of sunset frogs and identify peat systems that are likely to provide ecological refuge as well as peats potentially suitable for translocations (e.g., those that are most resilient to hydrological change); and 4) Investigate the relationship between suspected threats—fire, drought, feral animals, disease and habitat fragmentation—and the dynamics of frog populations, to better understand the processes impacting peat systems and their dependent fauna. Taken together, our findings can arm managers with a means to reverse declines, as well as provide new insights on how frogs and peatlands are impacted by the synergistic threats of fire and a drying climate.