Northern gastric-brooding frog
Rheobatrachus vitellinus Mahony, Tyler and Davies, 1984
Queensland Legislative Status: Endangered
Endemicity: Queensland endemic
Description: Size: males 42.6-58.3mm, females 47-83mm (Mahony et al 1984, Winter and McDonald 1986, McDonald and Alford 1999) Weight: males 11-26.5g, females 13-46.5g (McDonald and Alford 1999).
Rheobatrachus vitellinus is a moderately large, squat frog, with a blunt, rounded snout, and with nostrils directed upwards. The dorsal surface is pale brown with obscure darker patches on the body and limbs.
The ventral surface may be white or brown, with bright yellow-orange on the lower abdomen and undersides of the limbs. The skin is granular above, with large projections on the upper eyelid. The ventral surface is smooth. The fingers lack webbing, and the toes are fully webbed. The fingers and toes have slightly expanded tips. Males develop spinulated, unpigmented, nuptial pads on the first finger. The hind legs are short. The tympanum is not visible externally (Cogger 2000, Mahony et al. 1984).
Call: The call is loud and consists of several staccato notes repeated in a series (K. McDonald unpublished data). Males call from September to December (K.R. McDonald unpublished data).
Tadpole: The tadpole has not been described. Tadpoles of this species complete their development within the stomach of the mother (Leong et al. 1986, McDonald and Tyler 1984) and therefore are not free-swimming.
Reproduction: It is assumed fertilised eggs or embryonic tadpoles are swallowed by the female, the tadpoles completing their development in her stomach. The fully formed metamorphs are later regurgitated from the female's mouth. Females give birth in January to February (Winter and McDonald 1986). In the only documented case, 22 metamorphs were brooded by one female (McDonald and Tyler 1984). The morphological and physiological changes which female R. vitellinus undergo differ from the only other gastric brooding frog, R. silus (Leong et al. 1988).
Habitat: R. vitellinus is an aquatic species, confined to shallow, rocky, broken water areas in cascades, riffles, and trickles of fast flowing perennial streams in rainforest above 400m. During rain individuals are frequently observed on exposed rocks at night (McDonald 1990).
Distribution: Rheobatrachus vitellinus was found exclusively in undisturbed rainforest in Eungella National Park, mid-east Queensland at altitudes of 400-1000m (Covacevich and McDonald 1993, McDonald 1990). Rheobatrachus vitellinus has undergone a massive and rapid range contraction, and has not been located in the wild since March 1985 (McDonald 1990, McDonald and Alford 1999).
Latitude: Between 21º 0' and 21º 05'.
Longitude: 148º 34' and 148º 41'
National Parks: Eungella
Threatening processes: Rheobatrachus vitellinus was discovered in January 1984, and a monitoring program was immediately instituted by the Queensland National Parks and Wildlife Service to determine if this species was susceptible to a population decline such as the one which had led to the disappearance of its relative, R. silus. R. vitellinus was found to be quite common across the range, with up to six frogs occurring in a 2 x 5m riffle (McDonald 1990). However, by January 1985 no individuals could be located at a site on the edge of the distribution, though it was still present at other sites (Winter and McDonald 1986, McDonald 1990). Since March 1985, R. vitellinus has not been recorded from any site despite continued efforts to relocate it (Ingram and McDonald 1993, McNellie and Hero 1994, R. Retallick and J.M. Hero pers.comm.).
The causes of the population decline remain unknown. McDonald (1990) found no obvious evidence that seasonal rarity, over-collecting, drought, floods, habitat destruction, disease, heavy parasite loads or stress due to data collection were responsible for the population declines.
Current research is examining the possibility that a fungus may have caused the decline of this species ( Berger et al 1998, 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:
Rheobatrachus vitellinus is one of two species of frogs occurring in upland rainforest streams which have undergone substantial population declines in mid-east Queensland (McDonald 1990, Ingram and McDonald 1993). This species is currently listed as Endangered in the Queensland Nature Conservation Act (Wildlife) Regulation 1994, in the Commonwealth Endangered Species Act 1992, and ANZECC 1991. No populations of this species have been located since 1985.
Management Recommendations: A draft Recovery Plan has been compiled (Martin, W.E. and McDonald, K.R. 1996), which documents the flowing recommendations.
- Monitor sites where species were recorded historically to detect recovery of the species.
- Investigate disease in preserved specimens and other species occupying similar habitat.
- 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 R. vitellinus formerly occurred.
References:
Cogger,H.G. 2000. Reptiles & Amphibians of Australia. Reed New Holland, Sydney.
Couper,P.J. 1992. Hope for our missing frogs. Wildlife Australia.29(4): 11-12.
Covacevich,J.A. & McDonald,K.R.1993. Distribution & conservation of frogs & reptiles of Queensland rainforests. Memoirs of the Queensland Museum 34(1):189-199.
Ingram,G.J.& McDonald,K.R.1993. An update on the decline of Queensland's frogs. Pp 297-303 In Lunney,D. & Ayers,D.(eds),'Herpetology in Australia. A Diverse Discipline'.(Royal Zoological Society of New South Wales: Mosman).
Leong,A.S.-Y., Tyler, M.J., Shearman, D.J.C.1986. Gastric brooding: a new form in a recently discovered Australian frog of the genus Rheobatrachus. Australian Journal of Zoology 34: 205-209.
Mahony,M.J., Tyler,M.J. & Davies,M.1984. A new species of the genus Rheobatrachus (Anura: Leptodactylidae) from Queensland. Transactions of the Royal Society of South Australia 108(3): 155-162.
McDonald,K.R.1990. Rheobatrachus Liem & Taudactylus Straughan & Lee (Anura: Leptodactylidae) in Eungella National Park, Queensland : distribution & decline. Transactions of the Royal Society of South Australia 114(4): 187-194.
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.
McDonald,K.R., Covacevich,J.A., Ingram,G.J. & Couper,P.J.1991. The status of frogs & reptiles. Pp 338-345 In : Ingram,G.J. & Raven,R.J.(eds),'An Atlas of Queensland's Frogs,Reptiles,Birds & Mammals'.(Queensland Museum, Board of Trustees: Brisbane).
McDonald,K.R., & Tyler,M.J.1984. Evidence of gastric brooding in the Australian leptodactylid frog Rheobatrachus vitellinus. Transactions of the Royal Society of South Australia 108: 226.
McNellie,M. & Hero,J.M.1994. Mission amphibian. The search for the missing rainforest frogs of Eungella.Wildlife Australia 31(4): 22-23
Winter,J. & McDonald,K.R.1986. Eungella,the land of cloud. Australian Natural History 22(1): 39-43.
Last updated: 30 August 2005
