This species, an Australian endemic, occurred in disjunctive populations in three sub-coastal mountain ranges (Blackall, Conondale, and D’Aguilar Ranges) in the south-east Queensland region from Coonoon Gibber Creek in the north to Mount Glorious in the south (Czechura and Ingram 1990; Hines, Mahony and McDonald 1999). The extent of occurrence of the species was about 1,400km² (map in Hines, Mahony and McDonald 1999). Taudactylus diurnus occurred over a relatively narrow altitudinal range of 350-800m asl with most records falling between 500-800m asl (Czechura and Ingram 1990).
Habitat and Ecology
Taudactylus diurnus was associated with permanent and temporary watercourses in montane rainforests, tall open forest, notophyll vine forest and sclerophyll fern forest (Czechura and Ingram 1990). In addition, animals were also found along watercourses in pure stands of the palm Archontophoenix cunninghamia, in exposed areas, in gorges, in dense non-forest riparian vegetation (Lomandra longifolia, Carex neuroclamys, Elastostema reticulatum and Blechnum nudum) and where the riparian vegetation had been slightly infested with Lantana camara (Czechura and Ingram 1990). Permanent streams with rocky substrates were favoured, but this species also occurred in permanent and ephemeral streams on gravel, clay, sand and soil substrates (Czechura and Ingram 1990). Active frogs have been observed all year round, although less frequently during winter months (Czechura and Ingram 1990). Breeding occurred in warm weather after or during heavy rain from late October to May, with a January to March peak (Czechura and Ingram 1990; Meyer, Hines and Hero 2001d). Gravid females have been reported between November and May (Straughan and Lee 1966). Amplexus is inguinal and 24-36 eggs (2.2mm diameter) are deposited in gelatinous clumps under rocks or branches in the water (Liem and Hosmer 1973; Watson and Martin 1973; Czechura and Ingram 1990; Meyer, Hines and Hero 2001d). Tadpoles, illustrated by Liem and Hosmer (1973) and Watson and Martin (1973), were found throughout the year.
In the early 1970s it was considered to be relatively common (McEvoy, McDonald and Searle 1979), but it has not been sighted in the wild since 1979 despite continued efforts to relocate the species (Hines, Mahony and McDonald 1999). The disappearance of the species occurred over a period of three to four years, disappearing from the D’Aguilar Range in late 1975, then from the Blackall Range in late 1978, and finally from the Conondale Range in early 1979 (Czechura and Ingram 1990). There is no information on population size, structure, genetics or dynamics (Hines, Mahony and McDonald 1999). This species is now believed to be extinct.
The reason(s) for the disappearance of this species remains unknown. Like Rheobatrachus silus, logging has occurred in catchments occupied by the species (Hines, Mahony and McDonald 1999); however, the effect of timber harvesting on the species has not been investigated. The species’ habitat is currently threatened by feral pigs, invasion of weed species (especially mist flower) and altered stream flow and water quality due to upstream disturbances (Hines, Mahony and McDonald 1999). Taudactylus diurnus was not found in areas along watercourses that were heavily infested with Lantana camara or where the weeds Baccharis halimifilia and Agertina riparia (mist flower) occurred (Czechura and Ingram 1990). The frogs were also absent from streams with very muddy water associated with the activities of feral pigs (Czechura and Ingram 1990). From what is known from similar declines and disappearance elsewhere in the world, the disease chytridiomycosis also must be suspected as a cause for the decline.
The species' habitat is fully protected within a National Park.
Red List Status
Listed as Extinct because it has not been recorded in the wild since 1979, and extensive searches over the last 25 years have failed to locate this species.
Jean-Marc Hero, Sarah May, David Newell, Harry Hines, John Clarke, Ed Meyer 2004. Taudactylus diurnus. The IUCN Red List of Threatened Species 2004: e.T21530A9298760. http://dx.doi.org/10.2305/IUCN.UK.2004.RLTS.T21530A9298760.en .Downloaded on 20 February 2019