Former distribution and apparent disappearance of the Litoria aurea complex from the Southern Tablelands of New South Wales and the Australian Capital Territory

Frogs of the Litoria aurea complex were common and widespread in the Southern Tablelands of New South Wales and the Australian Capital Territory before they apparently suffered a major decline in abundance at the end of the 1970s. The extent of population declines in the species complex has been assessed by examination of museum specimens and records, evaluation of reports by experienced herpetologists and by undertaking field surveys, particularly in the Canberra region. Examination of museum material confirmed that three taxa occurred in the Southern Tablelands; L. aurea, L. raniformis and L. flavipunctata. Litoria aurea occurred only in the northern half of the Southern Tablelands, extending as far south as Canberra and Braidwood; L. raniformis occurred throughout much of the region at altitudes up to about 1 300 metres, but may not have occurred east of Lake George; and L. flavipunctata apparently had a restricted distribution near Canberra, Bombala and Delegate. Opportunistic surveys conducted since 1985 indicate that all members of the complex have disappeared from an extensive area of the Southern Tablelands centred on Canberra. Surveys have not been conducted in the southern Monaro or along the eastern edge of the tablelands where remnant populations may still occur. Long-term records of precipitation indicate that a series of severe droughts correlates with the period when members of the L aurea complex disappeared from the Southern Tablelands. However, the frogs also vanished from well-watered sites such as rivers, urban lakes and pools located in botanic gardens. This indicates that other unknown factors are likely to have been involved in the declines. Surveys to locate any remnant populations should be given a high priority and further research is required to determine the extent to which disease, climate change, increasing ultraviolet radiation and spread of the fish Gambusia influenced the population declines.