Green and Golden Bell Frogs in New South Wales: current status and future prospects

Surveys carried out between 1990 and 1995 of almost all known historic locations within New South Wales (including the ACT) for the Green and Golden Bell Frog Litoria aurea revealed that the species had suffered a dramatic decline in distribution and abundance in this region, with over 80% of all historic populations having gone extinct, and many of the extant populations being reduced to low numbers. The present study involved surveys of the Green and Golden Bell Frog locations that were known in 1995, surveys of new locations or potential areas for new locations of this species, and review of management plans and other documented information concerning particular populations. Over the last 12 years extinctions have continued with the loss of almost 50% of those sub-populations and 23% of populations known in 1995. Obviously the species cannot sustain this rate of loss for much longer and continue to exist within New South Wales. Protection for remaining extant populations is very limited and most are under continuing threat. Management plans have been prepared in relation to a number of sub-populations/ populations, but these plans have not focused on populations under current threat, and associated management actions designed to benefit this frog have occurred in only a few cases. Hence, decline of this species within NSW is likely to continue. Habitat change, mostly through destruction and disturbance, has been the major factor in population loss with the likelihood of extinction increasing with increases in the extent of habitat loss as measured by the number of habitat variables that have declined. Invasion by exotic predatory fish Gambusia holbrooki, previously linked with declines in this frog species, shows no apparent association with extinction of populations over the last 12 years and poses no apparent current threat to any population, apparently because any impact of this species has been ameliorated through the presence of submerged/ floating aquatic vegetation which may provide some protection against predation for eggs and tadpoles. The steps most likely to improve the conservation status of the Green and Golden Bell Frog within the state are habitat enhancement/ development and restoration of movement links between nearby populations.