This species was first located in 1976 and later described by Davies and McDonald (1979). It is known from four localities-Alexandra Creek (TR165); Hilda Creek (near Thornton Peak, Cape Tribulation National Park); Roaring Meg Cascades (via Mount Sorrow TR165); and Bluff Creek (Mossman Gorge Daintree National Park), north-east Queensland (Hero and Fickling 1994; M. Cunningham pers. comm.).
Habitat and Ecology
This species is known to be a rainforest specialist endemic to the Wet Tropics Bioregion (Williams and Hero 1998, 2001). As a stream-dwelling/stream-breeding species (Hero and Fickling 1994) it prefers fast-flowing streams in upland rainforest between 640 and 1,000m asl (McDonald 1992), although it might be present at lower altitudes (M. Cunningham pers. comm.). It has been found on granite boulders in notophyll vine forest in the splash zone near turbulent fast flowing water (Davies and McDonald 1979). There is no information on breeding season, timing of reproduction, or egg deposition sites. The tadpoles of the species have not been described but are thought to be torrent-adapted and similar to that of a sympatric species, Litoria nannotis (Davies and McDonald 1979). Unpigmented eggs (M. Cunningham unpubl.) are presumably laid in water under rocks in the stream.
It was once moderately common in suitable habitat, but it has undergone a dramatic decline. Despite recent efforts to locate the species, it has not been seen since 1991 (Ingram and McDonald 1993; Hero et al. 1998, 2002), and it might now be extinct. However, few searches for the species have been undertaken at historical sites (J-M. Hero and M. Cunningham pers. comm.).
The reason(s) for the decline of this species are unknown, although chytridiomycosis must be strongly suspected. The habitat of the species in the Wet Tropics has been protected since 1988; therefore, habitat destruction is no longer a threat (McDonald and Alford 1999). Current research is examining the possibility that disease, such as a viral and infection or chytrid fungus, might have contributed to the decline of this species (Berger, Speare and Hyatt 1999). Feral pigs have been suggested as a potential cause of riparian habitat damage and adult frog mortality (Richards, McDonald and Alford 1993). However, feral pigs are unlikely to have a direct impact due to the close association of this species with rocky cascades in streams (M. Cunningham pers. comm.).
The habitat of the species in the Wet Tropics has been protected within protected areas since 1988. This species is a priority for immediate survey work to determine whether or not it still survives at the localities from which it has previously been recorded. Research is also needed into the possible reasons for the decline of the species. Given the possible threat of chytridiomycosis, surviving individuals might need to form the basis for the establishment of an ex-situ population.
Jean-Marc Hero, Michael Cunningham, Ross Alford, Keith McDonald 2004. Litoria lorica. In: IUCN 2014