Sharp-snouted dayfrog
Taudactylus acutirostris (Andersson, 1916)
Queensland Legislative Status: Endangered
Endemicity: Queensland endemic
Description: Adult size(SVL):males 18.8-25.5mm, females 22.7-31.2mm (McDonald and Alford 1999.
Adult weight: males 0.6-1.6g, females 0.9-2.5g (McDonald and Alford 1999).
A small frog with narrow wedge shaped snout. Dorsum greyish olive - dark chocolate brown, may have dark V or W shaped markings. Broad, dark grey or black band, bounded above by distinct pale line, runs laterally from the level of the eye to groin.
Hind legs have darker cross bands, sometimes barely detectable, but usually quite conspicuous. The ventral surface is greyish white with dark flecks and blotches. Rear part of ventral surface and underside of the limbs are olive-yellow. Distinct white patch edged with black at base of each forelimb. Lower jaw edged with black. Skin is smooth above and below, with tubercles arranged in a triangle or ridges on lower back, and there's a distinct dorso-lateral skin fold. Fingers and toes have slightly expanded toe pads, and are fringed but lack webbing. (Liem & Hosmer 1973, Dennis 1982, Cogger 2000).
Call: Appears to have two calls. A high pitched metallic tinkling sound, "tink tink", repeated several times in quick succession (Liem & Hosmer 1973, Dennis 1982, Richards 1993), and a second call variously described as a popping call (McDonald 1992) or a short, scratchy chirp, "eek eek eek" (Ingram 1980, Richards 1993). Males call from exposed positions on rocks, sand or gravel banks at the waters edge, or from beneath rocks or leaves (Ingram 1980, K.R. McDonald pers. obs.). They call from first light, and may continue until early evening. The males establish territories (Dennis 1982). After a period of basking, individuals will move off to forage along the sides of creeks and the rainforest floor nearby. When disturbed they will leap into the water, and lie on the substrate for some minutes before resurfacing (Ingram 1980).
Tadpole: Tadpoles are small, with a dark, oval body, transparent and unpigmented posteriorly. Intestine visible dorsally, laterally and ventrally. Discrete spots across tail muscle and fins. Eyes are on top of the head, and the spiracle is sinistral, usually visible from above. Vent tube dextral. Oral disc surrounded by rows of marginal papillae with anterior gap. Two rows of teeth anterior to the jaws, and three posterior to the jaws. The inner two rows of teeth are divided in the middle (Liem & Hosmer 1973, Richards 1993).
Reproduction: Calling males and gravid females have been encountered year round (McDonald and Martin unpublished data). Females lay 25-40 large (2.2-2.7mm diameter) unpigmented eggs in a large gelatinous clump on the underside of rocks at or below the waterline in flowing creeks (Liem and Hosmer 1973).
Habitat: Taudactylus acutirostris are generally found among rocks and leaf litter along the edges of rainforest streams, though in wet weather they may be found some distance from the water (K.R. McDonald pers. obs.). T. acutirostris is a diurnal species, and will often bask in the sun. The tadpoles are lotic benthic normally inhabit debris in pools or slow flowing areas of rainforest streams (McDonald and Alford 1999, K.R. McDonald pers. obs.).
Distribution: T. acutirostris was widely distributed through the upland rainforests of the Wet Tropics, from Mt. Graham near Cardwell to Big Tableland approximately 30km south of Cooktown. The species underwent a dramatic range contraction in the late 1980's, to the northern boundary of its distribution. The last sighting occurred at Big Tableland in January 1995. An individual has recently been reported from Mount Father Clancy, South Johnstone R (Marshall 1998) but additional surveys have not located the species.
Latitude: Between 15&186; 42' and 18&186; 24';
Longitude: Between 145&186; 2' and 145&186; 57'.
National Parks: Cedar Bay, Daintree, Wooroonooran, Mt Hypipamee, Tully Falls, Lumholtz.
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. UV impact has been discounted in the tropics (McDonald and Alford 1999).
Status: Taudactylus acutirostris 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 (Ingram and McDonald 1993, Richards et al 1993, Trenerry et al 1994), with only three individuals reported from the wild since December 1994.
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.
- 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. nannotis 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.
Andersson, L.G. 1916. Results of Dr E. Mjoberg's Swedish scientific expeditions to Australia. 1910-1913. IX. Batrachians from Queensland. K. Svenska. Vatensk. Akad. Handl. 52(9): 1-20.
Cogger, H.G. 2000. Reptiles and Amphibians of Australia. Reed New Holland, Sydney.
Dennis, A. 1982. A brief study of the Sharp-snouted Torrent Frog Taudactylus acutirostris. North Queensland Naturalist 50: 7-8.
Hero, J.-M. and Fickling, S. 1994. A Guide to Stream-dwelling Frogs of the Wet Tropics Rainforests. James Cook University of North Queensland, Townsville.
Ingram. G. 1980. A new frog for the genus Taudactylus (Myobatrachidae) from mid-eastern Qld with notes on the other species of the genus. Memoirs of the Qld. Museum. 20(1):111-119.
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. and Hosmer, W. 1973. Frogs of the genus Taudactylus with description of two new species (Anura: Leptodactylidae). Memoirs of the Queensland Museum 16(3): 435-457.
Marshall, C.J. 1998. The reappearance of Taudactylus (Anura: Myobatrachidae) in north Queensland streams. Pacific Conservation Biology 4:39-41.,
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., 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