Common mistfrog
Litoria rheocola Liem, 1974
Queensland Legislative Status: Endangered
Endemicity: Queensland endemic
Description Size (SVL): males 27-36.4mm, females 28.4-41.2mm (McDonald & Alford 1999).Weight: males 1.2-3.3g, females 1.8- 4.55g (McDonald & Alford 1999).
A moderate size frog. The dorsal surface is dull grey or brown, with irregular darker markings. There is a distinct inverted triangle marking on the top of the head, stretching between the eyes down to the coccygeal region. An obscure darker band runs along the side of the snout, through the eye and ear to the shoulder.
The skin is smooth above, with scattered small tubercles. The ventral surface is granular, white in colour. The finger and toe discs are large. The fingers are moderately webbed, and the toes nearly fully webbed. The tympanum is small and covered by skin, though the rim may be distinct. The male nuptial pads are small, with fine dark spicules. The tip of the snout is bluntly pointed (Cogger 2000, Liem 1974).
Call: The call is a regular, repeated long drawn single note call, a rather nasal "wreek wreek wreek" (Liem 1974, McDonald 1992).
Tadpole: Tadpoles have a flattened, sandy coloured body, which is darker ventrally. The tail is very muscular, creamy yellow lightly dusted with diffuse dark pigment. The tail fins are clear, with only a few scattered melanophores confined to small aggregations. The mouth is suctorial, surrounded by marginal and submarginal papillae. There are two anterior and three posterior tooth rows (Richards 1992).
The tadpoles graze on algae-covered rocks in fast-flowing waters (Liem 1974).
Reproduction: Calling males and gravid females are found throughout the year (McDonald and Martin unpubl. data), and breeding has been observed during most months (Dennis & Trenerry 1984, Liem 1974). Large (1.4 - 1.8mm diameter) unpigmented eggs are deposited in a compact gelatinous clump under rocks in fast-flowing streams (Liem 1974).
Habitat: Litoria rheocola is usually found on rocks and vegetation near fast-flowing streams in rainforest from 0-1180m. Tadpoles are found in swiftly flowing rainforest streams, clinging to rocks in riffles, torrents, and highly oxygenated pools (Liem 1974).
Distribution: Species occurred in rainforests north of the Herbert River in the Wet Tropics from Lumholtz National Park to Amos Bay. Litoria rheocola has disappeared from most sites above 400m but lowland populations remain secure.
Latitude: Between 15&186; 41' and 18&186; 23' ;
Longitude: Between 144&186; 59' and 146&186; 4'.
National Parks: Lumholtz, Wooroonooran, Millstream, Crater Lakes, Mt Hypipamee, Daintree, Cedar Bay, Barron Falls.
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: L. rheocola is one of 7 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 (Ingram and McDonald 1993, Richards et al 1993, Trennery et al 1994). Declines first noted in 1989 (Richards et al. 1993), and progressed northward, effecting the northern-most site in 1994 (Ingram and McDonald 1993, McDonald and Martin 1995). Still common at lowland sites, but declined at most sites above 400m.
Management Recommendations: A draft Recovery Plan has been compiled ( Martin, W.E. and McDonald, K.R. 1995) and makes the following management recommendations.
- 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.
- Continue studies on the autecology on this species.
- 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. rheocola 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.
Dennis, A. and Trenerry, M. 1984. Observations on species diversity and habitat compartmentalisation of the frogs of Mt. Lewis rainforests, North Queensland. North Queensland Naturalist 52(184): 2-9.
Ingram, G.J. and McDonald, K.R. 1993. An update on the decline of Queensland's frogs. Pp 297-303 In Lunney, D. and Ayers, D. (eds), 'Herpetology in Australia. A diverse discipline'. (Royal Zoological Society of New South Wales: Mosman). 414pp.
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., 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