Mountain mistfrog
Litoria nyakalensis Liem, 1974
Queensland Legislative Status: Endangered
Endemicity: Queensland Endemic
Description: Size (SVL): 27-47mm (Hero & Fickling 1994, McDonald and Alford 1999).
A moderate sized, robust treefrog. The dorsal surface is uniform olive-brown or grey-brown, sometimes with irregular darker olive markings. The skin is smooth above, with scattered tubercles on the head and back. The ventral surfaces are granular, cream in colour with a reddish-pink flush on the limbs and pectoral region, and sometimes dotted or flecked with brown. The iris is brown. The finger and toe disks are large and conspicuous. The fingers have slight webbing, and the toes are fully webbed. The forearm is robust in the male, with a large nuptial pad with coarse spinules. The tympanum is small and indistinct, more or less covered by skin. (Cogger 2000, Liem 1974, Richards 1993).
Call: The call has been described as a regular, repeated rasping single note call (Liem 1974), or a soft, slow, popping growl (McDonald 1992).
Tadpole: Tadpoles have a depressed body, light brown in colour with a cream patch between the eyes, less distinct in large specimens. The tail muscle is very robust, cream with distinct light brown blotches that extends into the anterior portion of the clear fins. The tail fin is low anteriorly, high posteriorly and broadly rounded at the tip. The large suctorial oral disc is surrounded with marginal and submarginal papillae. There are two tooth rows anterior to the mouth, and three posterior to it (Richards 1992).
Reproduction: Little is known of the adult ecology. Mating calls have been heard from October to March (Liem 1974). Large unpigmented eggs are laid under rocks in riffles (Richards 1993). The tadpoles graze on algal-covered rocks in fast-flowing waters and will burrow into loose sand under rocks, which may help them to withstand the violent floods that often occur in rainforest streams. They commonly overwinter in upland streams, although those hatching in early summer can metamorphose before the next autumn. (Richards 1992).
Habitat: Litoria nyakalensis inhabits fast-flowing streams near riffles and cascades in upland rainforest, and are usually found perched on rocks or overhanging vegetation adjacent to the water (Liem 1974). Tadpoles are restricted to swiftly flowing rainforest streams. Within these streams they may be found clinging to rocks in riffles and torrents, and in highly oxygenated pools below waterfalls. Tadpoles have also been collected under rocks buried in sand (Richards 1992).
Distribution: Formerly occurred across two-thirds of the Wet Tropics from Douglas Creek near Cardwell to Alexandra Creek, Thornton Peak. This species underwent a rapid range contraction in the late 1980s, and has not been recorded since November 1990.
Latitude: Between 16&186; 7' and 18&186; 13';
Longitude: Between 145&186; 10' and 145&186; 51'.
National Parks: Daintree, Wooroonooran, Mt Hypipamee.
Threatening Processes: Suspected Threats: The causes of the decline remain unknown, Richards et al (1993) found no obvious evidence that drought, floods, habitat destruction or pollution by pesticides, inorganic ions or heavy metals were responsible for the population declines. Current research is examining the possibility that a disease may have caused the decline of this species (Berger et. al. 1999). Information on disease investigations and management can be located at http://www.jcu.edu.au/school/phtm/PHTM/frogs/ampdis.htm
Status: Litoria nyakalensis is one of seven species of frogs occurring in the upland rainforest streams of north-eastern Queensland which have undergone rapid and substantial population declines in the last decade (Richards et al 1993). L. nyakalensis has not been sighted since 1990 despite extensive surveys in 1991 -1992, and 1993 (Richards et al. 1993, Trenerry et al. 1994). Regular searches have been conducted throughout its range since 1993.
Management Recommendations: Draft Recovery Plan 1995 (Martin and McDonald 1995).
- Monitor historical localities to detect recovery.
- Investigate disease in preserved animals and species occupying similar habitat.
- Develop and refine husbandry techniques for rainforest stream dwelling frogs.
- Train park staff and community volunteers in identification of this species.
- Implement monitoring by park staff of select locations within the national park estate where L. nyakalensis formerly occurred.
References:
Berger, L., Speare, R, and Hyatt, A. 1999. Chytrid fungi and Amphibian declines: Overview, Implications and Future Directions. Pp23-33. In Campbell, A (ed), 'Declines and Disappearances of Australian frogs'. (Environment Australia, Department of the Environment and Heritage: Canberra). 234 pp.
Cogger, H.G. 2000. Reptiles and Amphibians of Australia. Reed New Holland, Sydney.
Hero, J.-M., Fickling, S. 1994. A Guide to Stream-Dwelling Frogs of the Wet Tropics Rainforests. Department of Zoology, James Cook University, Townsville.
Liem, D.S. 1974. A review of the Litoria nannotis species group and a description of a new species of Litoria from north-east Queensland, Australia. Memoirs of the Queensland Museum. 17(1): 151-168.
Martin, W.E. and McDonald, K.R. 1995. Draft Recovery Plan for the Threatened Stream-dwelling Frogs of the Wet Tropics. Qld Department of Environment and Heritage, Brisbane.
McDonald, K.R. 1992. Distribution patterns and conservation status of north Queensland rainforest frogs. Conservation Technical Report 1., Queensland Department of Environment and Heritage, Brisbane.
McDonald, K.R. and Alford, R.A. 1999. A Review of Declining Frogs in Northern Queensland. Pp14-22. In Campbell, A (ed), 'Declines and Disappearances of Australian frogs'.(Environment Australia, Department of the Environment and Heritage: Canberra). 234 pp.
Richards, S.J. 1992. The tadpole of the Australian frog Litoria nyakalensis (Anura, Hylidae), and a key to the torrent tadpoles of northern Queensland. Alytes 10(3): 99-103.
Richards, S.J. 1993. A guide to the identification of declining frogs and their tadpoles in the Wet Tropics Biogeographic Region, Queensland. Unpublished Report QDEH
Richards, S.J., McDonald, K.R., Alford, R.A. 1993. Declines in populations of Australia's endemic tropical rainforest frogs. Pacific Conservation Biology 1:66-77.
Trenerry, M. P., Laurance, W. F., and McDonald, K. R. 1994. Further evidence for the precipitous decline of endemic rainforest frogs in tropical Australia. Pacific Conservation Biology 1: 150-153.
Last updated: 30 August 2005