Distribution and Habitat
Population and Distribution
Taudactylus eungellensis is restricted to the ranges w. of Mackay, mid-e. Qld, from Clarke Range in the n. to Finch Hatton Gorge and Credition in the s. at altitudes between 200-1000 m (Ingram 1980; Covacevich & McDonald 1993). The area of occurrence of the species is less than 500 km2 (map in McDonald 1990). Taudactylus eungellensis was considered common across its range until Jan. 1985 when the first signs of the decline (Winter & McDonald 1986) were observed at lower altitudes (ie. about 400 m). At higher altitude the frogs were common until Mar. 1985, but were absent in Jun. of that year (McDonald 1990). A small population was recorded in the s. region of its distribution in Jun. 1986, but disappeared after that date (McDonald 1990). Tadpoles were present in the s. areas of the distribution until May 1987 (McDonald 1990). After a period of apparent absence, an individual was rediscovered in 1992 (Couper 1992) and the species has subsequently been recorded at nine scattered locations within Eungella NP (McNellie & Hero 1994; Retallick et al. 1997; Hero et al. 1998; Retallick 1998).
Populations of the species were monitored throughout 1994-1998 along sections of streams at altitudes between 180 and 980 m (Retallick et al. 1997; Retallick 1998). Population sizes differed noticeably between sites but appeared to be consistent over time. Interestingly, a significant proportion of each population was recaptured with each visit, which suggests that the population turnover is low, and that the population size is also low. The monitored populations are a large population at Rawson Ck, a medium-sized population at Dooloomai Falls, and a small population at Tree Fern Ck. Frogs at other sites were caught too irregularly to provide useful information. Although the numbers of frogs found at these sites are encouraging and appear to be slowly increasing (Retallick et al. 1997), at Dooloomai Falls the current number of frogs remain substantially lower than were recorded before the precipitous population declines in 1985/86 (McDonald pers. comm. in Retallick et al. 1997).
Taudactylus eungellensis is known from Eungella NP, Cathu and Mt Pelion SF, SF 62 Eungella and Gamma, and on Dalrymple Road Farm adjacent to the NP and SF (Tyler 1997).
Taudactylus eungellensis occurs along small creeks in rainforest as well as wet sclerophyll forest (Liem & Hosmer 1973). The immediate streamside habitat is dense rainforest with ferns, vines, palms and epiphytes in the understorey (Retallick et al. 1997). The species inhabits exposed steep, rocky sections of stream within splash zones of waterfalls and cascades (McNellie & Hero 1994; Retallick et al. 1997) and may be found under rocks and crevices or on emergent rocks in the stream (Liem & Hosmer 1973; Retallick et al. 1997). Tadpoles are found in first to third order streams in large and relatively still mid-stream pools, or partially connected stream-side pools (Retallick & Hero 1998). Tadpoles have been observed in the benthic layer among rocks, litter, and detritus (Retallick & Hero 1998).
Habitat and Ecology
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1994Endangered(Groombridge 1994)
Life History, Abundance, Activity, and Special Behaviors
Taudactylus eungellensis is a stream dwelling/stream breeding species. Males call during the day throughout most of the year with a peak in activity and calling during autumn and warmer months of the year (Retallick et al. 1997). About 30 - 50 pigmented eggs are laid though sites of oviposition are unknown (Liem & Hosmer 1973; Retallick and Hero 1998). Retallick and Hero (1998) described the tadpole of the species. T. eungellensis has a peak breeding season between Jan. and May, but tadpoles of all sizes and developmental stages may be found throughout the year (Retallick and Hero 1998). Newly hatched tadpoles have been recorded in Apr., May and Dec. (Retallick et al. 1997). Metamorphosis occurs between Nov. and Jan. (Retallick and Hero 1998).
Experiments on the tadpoles of the species suggest that the majority of their diet is made up of detritus (Retallick et al. 1997). The tadpoles of T. eungellensis are unusual in that they do not possess labial tooth rows and this implies that they feed on soft foods growing on the substrates (like algae), rather than shredding and ingesting the substrate itself (Retallick et al. 1997). The diet of adults remains unknown.
Forest grazing and trampling of streamside vegetation by livestock have been identified as possible threats to the species, but there is no evidence to support this (Dadds 1999). Cane toads Bufo marinus may be able to penetrate natural habitats along roadways and utilise ponds for breeding, but there is no evidence of this occurring (Dadds 1999) nor that this may affect T. eungellensis (R. Retallick pers. comm.).
Taudactylus eungellensis is active during day and night (Liem &Hosmer 1973; Retallick et al. 1997). The species is a true stream-dwelling frog, and spends its entire life at the stream (Retallick et al. 1997). Males, females and juveniles are caught consistently at the stream in nearly equal numbers (Retallick et al. 1997). Retallick et al. (1997) noted that a significant proportion of each population is recaptured with each visit, and that there was very little movement up or downstream, with average movements less than 20 m. Under these conditions, gene flow among populations in different catchments is likely to be minimal (Retallick et al. 1997). However, studies on genetic variation of T. eungellensis populations in Eungella NP have shown that only one of the populations examined (at Boulder Creek) is genetically semi-isolated from the other five populations in the area (Oke 1996). The possibility of gene flow between this population and the other populations is low due to site fidelity of adult frogs (Retallick et al. 1997), geographic barriers (between stream catchments) and other natural barriers such as the presence of fish (Oke 1996). The other populations showed genetic signs of interbreeding (Oke 1996).
Life History, Abundance, Activity, and Special Behaviors
The cause(s) of the decline remains unknown. McDonald (1990) found no obvious evidence that seasonal rarity, over-collecting, drought, floods, habitat destruction, heavy parasite loads or stress due to handling and data collection were responsible for the population declines. Sick and dying frogs have occasionally been encountered (Hero et al. 1998, Hero et al. in press) and it may be that the fungal disease, Chytridiomycosis, has had an impact on the population (Berger et al. 1998).
- Berger, L., Speare, R., Daszak, P., Green, D. E., Cunningham, A. A., Goggin, C. L., Slocombe, R., Ragan, M. A., Hyatt, A. D., McDonald, K. R., Hines, H. B., Lips, K. R., Marantelli, G., and Parkes, H. (1998). "Chytridiomycosis causes amphibian mortality associated with population declines in the rain forests of Australia and Central America." Proceedings of the National Academy of Sciences of the United States of America, 95(15), 9031-9036.
- 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.'' Memoirs of the Queensland Museum, 34(1), 189-199.
- Dadds, B. (1999). Taudactylus eungellensis, Eungella Torrent Frog. Queensland Department of Natural Resources.
- Hero, J-M., Hines, H.B., Meyer, E., Morrison, C., and Streatfeild, C. (1999). ''New records of 'declining' frogs in Queensland (April 1999).'' Frogs in the Community â" Proceedings of the Brisbane Conference 13â"14 February 1999. R. Natrass, eds., Queensland Museum, Brisbane.
- Hero, J.-M., Hines, H.B., Meyer, E., Morrison, C., Streatfeild, C., and Roberts, L. (1998). ''New records of 'declining' frogs in Queensland, Australia.'' Froglog, 29, 1-4.
- Ingram, G. (1980). ''A new frog of the genus Taudactylus (Myobatrachidae) from mid-eastern Queenlsand with notes on the other species of the genus.'' Memoirs of the Queensland Museum, 20(1), 111-119.
- 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), 534-457.
- McDonald, K.R. (1990). ''Rheobatrachus Liem and Taudactylus Straughan and Lee (Anura: Leptodactylidae) in Eungella National Park, Queensland: distribution and decline.'' Transactions of the Royal Society of South Australia, 114(4), 187-194.
- McNellie, M. and Hero, J.-M. (1994). ''Mission amphibian: the search for the missing rainforest frogs of Eungella.'' Wildlife Australia, 31(4), 22-23.
- Oke, C.S. (1996). Towards Conservation Priorities for the Threatened Stream Dwelling Frog Taudactylus eungellensis Using Mitochondrial DNA (MTDNA) Sequence Data. LaTrobe University, Melbourne.
- Retallick, R. (1998). Population Monitoring of Stream Dwelling Frogs at Eungella National Park. Final Report submitted to EA/QPWS.
- Retallick, R.W.R. and 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.'' Journal of Herpetology, 32(2), 304-309.
- Retallick, R.W.R., Hero, J.-M., and Alford, R.A. (1997). Adult population monitoring and larval ecology of the stream-dwelling frogs at Eungella National Park. Final report submitted to ANCA/QDOE, February 1997.
- Tyler, M.J. (1997). The Action Plan for Australian Frogs. Wildlife Australia, Canberra, ACT.
- Winter, J. and McDonald, K. (1986). ''Eungella, the land of cloud.'' Australian Natural History, 22(1), 39-43.
Eungella torrent frog
It is a relatively small frog reaching 35mm in length. The head and body are slender and the limbs are long and lean. The dorsum ranges from yellowish-tan to dark brown in colour with darker mottling. There is a X-shaped marking on the back. The front half of the head is usually lighter than the back half and the arms and legs have banding. The toes and feet have wedge-shaped pads and no webbing. The back is smooth or granular with a few low warts. The belly is smooth and deep yellow. The irises restrict horizontally and are golden. The tympanum is indistinct.
Ecology and behaviour
This frog inhabits montane rainforest and tall open forests. It is found in and around flowing creeks. If alarmed the Eungella Torrent Frog may jump into the creek where it will hide beneath rocks until the danger has passed. Breeding may occur all year round but is most intense from November to December. Males make a soft tinkering sound barely audible over the sound of cascading water. Eggs are laid in clumps of 30-50. They are attached to the under surface of submerged rocks or logs. The Eungella torrent frog is the only Myobatrachidae that is known to advertise its presence by the movement of its body and limbs. It is suspected that these movements are a form of courtship. These movements include: flicking and waving of legs, head bobbing, and distinctive hops.
This species is the only known Australian frog to go through an apparent period of absence, only to later reappear. The Eungella torrent frog was first noted to be in decline in the 1980s. From 1987 to 1992 the frog was not encountered, despite surveys. From 1992 onwards it has since been rediscovered at nine sites and populations appear to be slowly on the rise. Although these results are encouraging, populations have not rebounded to what they were before the decline, when they were still considered common. The cause for decline is believed to be the chytrid fungus Batrachochytrium dendrobatidis, however interestingly the frogs now seem to be able to coexist with the fungus that once caused their near extinction.
- Retallick et al. (2004). Taudactylus eungellensis. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 11 May 2006. Database entry includes a range map, a brief justification of why this species is critically endangered, and the criteria used.
- PloS Journal
- Frogs Australia Network - call available here
- Barker, J.; Grigg, G.C.; Tyler,M.J. (1995). A Field Guide to Australian Frogs. Surrey Beatty & Sons.
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