An update on the status of wet forest stream-dwelling frogs of the Eungella region

Eungella’s wet forests are home to a number of stream-breeding frogs including three species endemic to the Eungella region: the Eungella dayfrog (Taudactylus eungellensis), Eungella tinkerfrog (T. liemi), and northern gastric brooding frog (Rheobatrachus vitellinus). During the mid-1980s, T. eungellensis and R. vitellinus suffered dramatic population declines attributable to amphibian chytridiomycosis, a disease caused by the amphibian chytrid fungus (Batrachochytrium dendrobatidis or Bd). While surveys in the late 1980s failed to locate T. eungellensis or R. vitellinus, populations of the former were located on a handful of streams surveyed by researchers in the mid-to-late 1990s. Between January 2000 and November 2015, additional surveys targeting these and other wet forest frog species were conducted at 114 sites within Eungella National Park and adjoining areas of State Forest. During these surveys, we located T. eungellensis at many more sites than surveys in the 1990s. Abundances of T. eungellensis at these sites were typically low, however, and well below abundance levels prior to declines in the mid-1980s. As with surveys in the 1990s, T. eungellensis was scarce at high-elevation sites above 600 metres altitude. Numbers of this species do not appear to have increased significantly since the mid-1990s, suggesting recovery of T. eungellensis populations is occurring slowly, at best. In contrast with T. eungellensis, T. liemi was frequently recorded at high-elevation sites, albeit at low densities. As with previous surveys, surveys during 2000–2015 were unsuccessful in locating R. vitellinus. Further frog surveys and monitoring (including disease surveillance) are needed to better assess the status of stream frogs at Eungella, and to understand the influence of Bd on the abundance and distribution of threatened stream-dwelling frogs at Eungella.