Abiotic and Biotic Factors Influencing the Assemblage of Tadpoles and Adult Anurans in Coastal Wallum Habitats of Eastern Australia

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The emergence of the global amphibian crisis has seen the extinction of 122 species worldwide, with 18.8% of Australia’s 213 amphibian species being threatened. Despite these declines, little is known about the biology and ecology of certain Australian threatened species. Hence, successful conservation and management of threatened amphibian species cannot be fully realised. Several environmental variables may influence amphibian adult or tadpole assemblages. These variables include, but are not limited to, water chemistry factors (i.e. pH, salinity, turbidity), predation, competition, hydroperiod and water flow. These variables will influence individual species differently, with each species displaying differences in tolerance to these specific variables. The coastal wallum vegetation along the eastern coast of Australia is the primary habitat for four specialist frog species (Litoria olongburensis, Litoria freycineti, Litoria cooloolensis and Crinia tinnula) that are listed as Vulnerable under the IUCN Red List. All species are referred to as ‘acid’ frogs due to their association with low pH waters. ‘Acid’ frog populations within protected areas are believed to be stable. However, populations of ‘acid’ frogs occurring outside of protected areas are at risk from ongoing habitat loss and fragmentation. It is therefore vital that conservation managers know which environmental factors influence ‘acid’ frogs to ensure these environmental variables remain constant and populations remain stable. Furthermore, it is imperative to determine if these environmental variables are the same within anthropogenic waterbodies and if ‘acid’ frogs utilise anthropogenic waterbodies. This knowledge would assist in the future prioritisation of waterbodies for conservation. However, the factors influencing ‘acid’ frog species tadpole and adult relative abundance and occupancy within protected and non-protected wallum heathland waterbodies have not been reported.