Rapid Turnover in Site Occupancy of a Pond-breeding Frog Demonstrates the Need for Landscape-level Management

Habitat loss and habitat isolation have contributed to declines in the green and golden bell frog (Litoria aurea) over much of its former range in south-eastern Australia. Understanding the parameters critical for the persistence of extant populations is required to halt further declines. We assessed waterbody occupancy in a local network of potential L. aurea breeding habitats on Kooragang Island, Australia, by conducting surveys over two years (2000 and 2001) at 30 waterbodies, and using site-occupancy models. The probability that a waterbody was used by L. aurea in 2000 increased with increasing waterbody area, and decreasing distance to the nearest waterbody where L. aurea was detected and where reproductive recruitment was observed. Large waterbodies where high numbers of L. aurea were detected in 2000 were more likely to be used in 2001. The probability that a waterbody used in 2000 was not used in 2001 (i.e., turnover) decreased with increasing waterbody area and increasing numbers of L. aurea detected at the site in 2000. Our results demonstrate the potential for frog abundance, immigration, and recruitment to reduce local turnover. We recommend that conservation strategies for extant populations of L. aurea protect mosaics of wetland habitat and maintain connectivity among waterbodies.