Project 3.3 'Targeted surveys for missing and critically endangered rainforest frogs in ecotonal areas, and assessment of whether populations are recovering from disease'

Led by: Dr. Robert Puschendorf, Plymouth University

Led by: Dr. Conrad Hoskin, James Cook University

Ten frog species disappeared from the upland rainforests of the Wet Tropics and Eungella during outbreaks of amphibian chytrid fungus (Batrachochytrium dendrobatidis) in the late 1980s and early 1990s, representing 25% of the frogs endemic to the Wet Tropics and all of the Eungella endemics. Five of these species occurred only in the uplands and have been presumed extinct because no individuals have been found despite intensive searches. This represents a significant loss of endemic species diversity, particularly in the Wet Tropics World Heritage Area. The exciting recent development is that researchers recently rediscovered one of these ‘extinct’ species, the Armoured Mistfrog (Litoria lorica) in high elevation dry sclerophyll forest close to rainforest sites it vanished from. Equally exciting is that this population coexists with chytrid fungus, suggesting that at some sites these species can persist with the pathogen. This rediscovery strongly suggests that other missing frogs may well still be out there (including Litoria nyakalensis, Taudactylus acutirostris, Taudactylus rheophilus and even the Northern Gastric Brooding Frog Rheobatrachus vitellinus) but have been overlooked because searches have focussed on rainforest and not the adjacent dry forest.

This project will survey dry forest ecotonal sites and adjacent rainforest sites for missing and endangered frogs of the Wet Tropics and Eungella, and also survey vertebrates more broadly at these sites. It will also determine whether threatened frogs are recolonising upland rainforest sites from which they disappeared in the past, and the mechanisms of this delivery; determine whether the few minute populations of Taudactylus rheophilus recorded after disease outbreaks have persisted; and provide management recommendations and a list of critical ecotonal areas, which act as disease refugia for critically endangered rainforest frogs, or areas of importance for other vertebrate species.

Project objectives at a glance

This project is essential if researchers are to determine:

Whether the ‘extinct’ frogs of the Wet Tropics and Eungella are really extinct;
Whether the dry forest/rainforest ecotones of the western Wet Tropics and Eungella harbour overlooked populations of these and other critically endangered species; and
Whether threatened frogs are recovering from chytrid disease.

Results from this research will also help to determine how widespread chytrid is across the study regions and environments, and how frogs are currently dealing with this threat. The project will provide important survey data and genetic samples for vertebrates more broadly in these poorly surveyed areas, providing key material for understanding the evolution of rainforest communities and their resilient to future change.

Specific objectives and intended outputs of this Project are detailed in the NERP TE Hub Multi-Year Research Plan.

Final Report

The importance of peripheral areas for biodiversity conservation: with particular focus on endangered rainforest frogs of the Wet Tropics and Eungella

Project Factsheet