National recovery plan for Stream Frogs of South-east Queensland 2001-2005
Prepared by Harry Hines
Queensland Parks and Wildlife Service
and the South-east Queensland Threatened Frogs Recovery Team, 2002
Appendix 1. Species Profiles
Kroombit Tinkerfrog Taudactylus pleione Czechura 1986
- Current distribution
- Conservation status
Taudactylus pleione is a small frog, with adults growing to a snout-vent length between 25-35mm. It is reddish brown to grey dorsally with darker brown flecks, spots and blotches. Of these dark markings there is a prominent broad bar of approximately uniform width between the eyes, a roughly X-shaped blotch between the shoulders, broad lateral bands and a bar or blotch either side of the groin. A broad dark lateral stripe extends from the snout through the eye and ear. Limbs and digits have conspicuous dark cross-bars and digits are not webbed. The toes are indistinctly flanged. The posterior surface of thighs is dirty yellow, with brown bars and specks. The venter is smooth, translucent grey with dense cream and brown mottling and speckling. (M. Cunningham unpublished data, Czechura 1986a, Meyer et al. 2001)
The call is a high-pitched 'tink-tink-tink-tink...', fast at first, slowing towards the end (Meyer et al. 2001).
Taudactylus pleione has been heard calling from September until early March, with peaks in calling most likely on warm nights between December and February. During winter the species appears to be inactive and possibly hidden deep inside rocky shelves or under large boulders. During the suspected summer breeding season, calling activity varies from night to night but is generally strongest at dusk and early evening, with infrequent calls in the afternoon. When calling vigorously, males may call all night and into the following day. Frogs have been seen or heard calling from rocky perches, crevices or forest debris within close proximity to watercourse channels or intermittent seepages, and are usually at least partially sheltered by leaves or rocks. (Clarke et al. 1999, QPWS unpublished data, Tangey and Clarke in press) There is virtually no information on the female breeding cycle, although there are three records of gravid females, one (the holotype) collected early February, the second seen in mid-January and the third, with partially developed eggs, in December. Eggs, oviposition sites, and tadpoles have not been described. (Clarke et al. 1999, Meyer et al. 2001, QPWS unpublished data)
Recorded only in small, narrow, isolated patches of gully rainforest. Found amongst or under rocks and leaf litter in the vicinity of permanent and ephemeral, rocky seepage zones. Vegetation at sites on the plateau is dominated by Ceratopetalum apetalum, and/or Archontophoenix cunninghamiana often with emergent Araucaria cunninghamii. Wet sclerophyll species including Eucalyptus saligna and Lophostemon confertus occur along the rainforest margins but are replaced by drier forest eucalypts further up-slope. Populations below the escarpment occur in steep boulder strewn drainage lines that are dominated by Archontophoenix cunninghamiana closed forest with emergent Araucaria cunninghamii and other rainforest trees. (Borsboom et al. 1999, Clarke et al. 1999, Cunningham and James 1994, Czechura 1986a)
Taudactylus pleione is currently known from only nine small patches of rainforest at Kroombit Tops west of Miriam Vale in south-east Queensland. Three of these are isolated patches between 800-850m altitude on separate drainage lines of the headwaters of Kroombit Creek. These patches are in Kroombit Forest Reserve (formerly Scientific Area 48 in Kroombit Tops State Forest). The frog was recently located in six rainforest patches on the headwaters of Degalgil and Diglum Creeks in the Boyne River catchment. These patches are in Kroombit Tops National Park just below the escarpment adjacent to Kroombit Tops Forest Reserve. The total area of known frog habitat is approximately 140ha. The nine occupied patches are estimated to be scattered within an area of about 700ha, (Figure 5). (Clarke et al. 1999, Cunningham and James 1994, Czechura 1986a, Czechura 1986b, QPWS unpublished data)
|Figure 5. Distribution of Kroombit tinkerfrog Taudactylus pleione and Kroombit Tops population of Litoria pearsoniana.|
The only intensively monitored population, at the head of Kroombit Creek, appears to have declined. At this site the species was regularly encountered prior to 1997 but was not heard or seen during the 1997/98 season despite systematic monitoring. The frog was heard at three other sites during limited surveying and monitoring in the 1997/98 season (Hines et al. 1999). The site has been monitored regularly since and T. pleione has only been heard on one occasion (QPWS unpublished data).
In the 1997/98 season automated tape recorders were installed at the monitoring site to increase survey effort. Recordings were also made in the 1998/99 and 1999/2000 seasons. During this time T. pleione was not heard on any of these recordings but it was regularly detected at another site using the same methods (QPWS unpublished data).
Potentially vulnerable to the unknown causal agent(s) that have resulted in the decline or disappearance of several species of frogs including four of the six Taudactylus species from rainforest streams in Queensland over the last 15 years (Ingram and McDonald 1993, Hines et al. 1999).
Likely to be susceptible to trampling and increased nutrient loads resulting from grazing in, and upstream of, habitat areas. Trampling may also alter the hydrology of seepage areas. Very likely to be susceptible to predation and habitat destruction by pigs. Pigs have recently become established at Kroombit Tops, and have caused significant damage to at least two sites occupied by T. pleione. The effect of this damage is not yet known. A wildfire in 1984 caused significant damage to a number of the small rainforest pockets from which T. pleione is known. Management of fire at Kroombit Tops is critical to the conservation of T. pleione. (Borsboom et al. 1999, Clarke et al. 1999)
It is listed as vulnerable nationally, in Queensland and in the Action Plan. A review of its legislative status is urgently required as it meets IUCN (2001) criteria for Critically Endangered [B1ab(iii, iv)].