Eungella dayfrog
Taudactylus eungellensis Liem and Hosmer, 1973
Queensland Legislative Status: Endangered
Endemicity: Queensland endemic
Description: Size (SVL): males 23.8-32mm, females 25.5-37.11mm (R. Retallick in McDonald and Alford 1999).
Weight: males 0.8-3.7g, females 1.9-5g (R. Retallick in McDonald and Alford 1999).
T. eungellensis is a small frog, with a bluntly acuminate snout. The dorsal surface may be yellowish tan to dark brown, with irregular dark brown markings. A broad band crosses the head between the eyes, with two other anterior to this. A black band extends from behind the eye to the base of the fore arm, and there is a prominent irregular X-shaped marking on the back.
There are cross-bands on the limbs and digits. The throat and abdomen are white or cream-coloured, and the ventral surfaces of the limbs are bright yellow, with or without dark brown spots. The skin is shagreened with tubercles above, the postero-medial portion of the thighs is granular, and the ventral surface is smooth. The fingers and toes have expanded tips, and are broadly fringed but lack webbing. Males have finely spinulated, rounded nuptial pads like a blister on the back of the hand at the base of the second and third fingers. Males do not possess a vocal sac. The typanum is hidden. (Liem and Hosmer 1973, Cogger 2000)
Call: Calling has been heard during most months of the year with the greatest intensity during spring and summer. The call is a gentle rattling sound barely audible over the sound of rushing water (Winter and McDonald 1986). T. eungellensis is largely diurnally active with calling during the day, though males will call at night (McDonald 1990, McNellie 1994). They bask on exposed rocks, and when disturbed escape into the water, remaining submerged on the bottom for some time (Couper 1992, Liem and Hosmer 1973). Males have been observed communicating by visual cues, which include flicking and waving of legs, head bobbing, and distinctive hops.
Tadpole: The tadpole is orange brown, with a distinctive V-shaped marking behind the eye, and dark pigment around the base of the tail and upper surface of the tail muscle. The body is oval and the fins clear and narrow, with a rounded tail tip. The spiracle is sinistral, the vent dextral. The oral disc is small and completely surrounded by a single row of small marginal papillae, with the posterior edge of the papillae skirt indented toward the mouth medially. There are no labial teeth, but there are 3 papillar ridges on the posterior labium. Keratinous jaws pigmented, small and weak (Liem & Hosmer 1973; Retallick & Hero, 1998). The tadpoles are bottom dwellers in pools and slow flowing sections of rainforest steams.
Reproduction: T. eungellensis is a late summer breeder and oviposition occurs from November to May (Liem and Hosmer 1973, McDonald 1990). Females lay 30-50 large (2.2 - 2.6 mm) eggs under rocks in the water (Liem and Hosmer 1973). The tadpoles do overwinter (McDonald 1990, Retallick & Hero 1998). Metamorphosis occurs between November and January (Retallick & Hero 1998).
Habitat: Taudactylus eungellensis inhabits exposed rocky sections in the splash zones of riffles, cascades and waterfalls of rainforest streams. They may be found under rocks and crevices or in more exposed positions (Liem and Hosmer 1973, McDonald 1990, McNellie and Hero 1994).
The tadpoles are benthic, inhabiting mid-stream pools or partially connected stream-side pools (Retallick & Hero 1998).
Distribution: Former: T. eungellensis is restricted to a small area of the Clarke Range, mid-east Queensland at altitudes of 200-1000m (Covacevich and McDonald 1993).
Current: T. eungellensis has undergone a rapid and dramatic range contraction, and after a period of apparent absence, has now been located at nine sites within its former distribution (McNellie and Hero 1994, R. Retallick pers. comm.).
Latitude: Between 20&186; 48' and 21&186; 13';
Longitude: Between 148&186; 9' and 148&186; 43'
National Parks: Eungella
Threatening processes: Suspected threats: Taudactylus eungellensis is one of two species of frogs occurring in upland rainforest streams in mid-east Queensland which have undergone substantial population decline (McDonald 1990, Ingram and McDonald 1993).
The species was considered common across its range, occurring in large numbers (up to ten per square metre) over long stretches of streams at high and low altitude (McDonald 1990, M. Mahony pers. comm.). T. eungellensis disappeared from lower altitudes in January 1985, and by June 1986 adults could not be found despite repeated visits to monitored sites (Winter and McDonald 1986). Tadpoles could still be found in the southern parts of its distribution until May 1987 (McDonald 1990). Periodic searches continued unsuccessfully until July 1992, when an adult was caught and photographed (Couper 1992). Subsequent searches between November 1993 and August 1998 have located small numbers of adults, subadults, metamorphs and tadpoles at nine sites within Eungella National Park (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 handling and data collection 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: 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.
Management Recommendations: A draft Recovery Plan has been compiled (Martin, W.E. and McDonald, K.R. 1996) which documents the following 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.
- Continue studies on the autecology of 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 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. and McDonald, K.R. 1993. Distribution and conservation of frogs and reptiles of Queensland rainforests. Mem. Q. Mus. 34(1):189-199.
Ingram, G. 1980. A new frog of the genus Taudactylus (Myobatrachidae) from mid-eastern Queensland with notes on the other species of the genus. Mem. Q. Mus. 36(1): 111-19.
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).
Liem, D.S. and Hosmer, W. 1973. Frogs of the genus Taudactylus with descriptions of two new species (Anura: Leptodactylidae). Mem. Q. Mus. 16: 435-457.
McDonald, K.R. 1990. Rheobatrachus Liem and Taudactylus Straughan & Lee (Anura: Leptodactylidae) in Eungella National Park, Queensland: distribution and decline. Trans. R. Soc. SA 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. and Couper, P.J. 1991. The status of frogs and reptiles. Pp 338-345 In Ingram, G.J. and Raven, R.J. (eds), 'An Atlas of Queensland's Frogs, Reptiles, Birds and Mammals'. (Queensland Museum, Board of Trustees: Brisbane).
McNellie, M. and Hero, J.M. 1994. Mission amphibian. The search for the missing rainforest frogs of Eungella. Wild. Aust. 31(4): 22-23
Retallick, R.W.R. & Hero, J.-M. (1998). The tadpoles of Taudactylus eungellensis and T. liemi and a key to the stream-dwelling tadpoles of the Eungella rainforest in east-central Queensland, Australia. J. Herp. 32(2), 304-309.
Winter, J. and McDonald, K.R. 1986. Eungella, the land of cloud. Aust. Nat. Hist. 22(1): 39-43.
Last updated: 30 August 2005