Review of the past distribution and decline of the southern bell frog Litoria raniformis in New South Wales

The Southern Bell Frog Litoria raniformis was formally widespread throughout south eastern Australia. Poor knowledge of the past and present distribution of populations and the pattern of decline currently limits our ability to plan conservation measures. The past and present distribution of L. raniformis in New South Wales (NSW) is described through the use of museum records, wildlife databases, reports and surveys. Survey identified a further 10 populations, all in lower Murrumbidgee floodplain (Lowbidgee), and confirmed the absence of L. raniformis in past habitats along the middle reaches of the Murrumbidgee River. Based on past records, L. raniformis declines have been substantial. The eastern edge of the geographic range has shifted approximately 500 km west from the South Eastern Highlands, and the northern edge of its range has shifted 200 km south from the most northerly population in Willandra National Park. Litoria raniformis is currently restricted to the semi-arid zone of NSW with populations occurring in the Lower Murrumbidgee and Murray River, the Wakool Irrigation Area and the Coleambally Irrigation Area. The wide geographic range of L. raniformis prior to the decline means that a single causal factor is unlikely. Former habitats throughout the original range have been highly modified as a result of a range of factors, including flooding regulation, livestock grazing and exotic introductions.