Mountain Mistfrog

Population and DistributionLitoria nyakalensis formerly occurred across two thirds of the Wet Tropics from Douglas Ck near Cardwell to Alexandra Ck, Thornton Peak n.e. Qld (Hero & Fickling 1994) at altitudes between 380-1020m (McDonald 1992). The historical area of occurrence of the species is around 6000 km2 (M. Cunningham pers. comm.). Adult L. nyakalensis were last recorded in Apr. 1990, and tadpoles and metamorphs were last recorded in Nov. 1990 on the Carbine Tableland (Richards et al. 1993). However, this species had apparently disappeared from sites on the Atherton Tableland much earlier (Richards et al. 1993). It was recorded from various sites on the Atherton Tableland prior to 1973 (Liem 1974), but was not encountered in Danbulla SF during 1989-1992 or at any Atherton Tableland site during surveys conducted between 1991 and 1992 (Richards et al. 1993). No information is available on population structure or genetic variation (M. Cunningham pers. comm.).Formerly known from Wooroonooran, Daintree, Crater Lakes, Crater and Palmerston NP, Mt Lewis, Maalan, Ravenshoe, Herberton Range, and Kirrama SF, SF758 Alcock, Daintree Timber Reserve (165 Monkhouse) (Tyler 1997; M. Cunningham pers. comm.). HabitatLitoria nyakalensis was a rainforest specialist, endemic to the W.T. Bioregion (Williams & Hero 1998; 2001) found in upland rainforest and wet sclerophyll forest along fast-flowing streams where there is white water from riffles and cascades (Liem 1974; McDonald 1992). It is usually found perched on rocks or overhanging vegetation adjacent to the water (Liem 1974). The tadpoles are restricted to fast-flowing waters where they may be found clinging to rocks in riffles and torrents and in highly oxygenated pools below waterfalls (Liem 1974; Richards 1992). Tadpoles will also burrow into loose sand under rocks which may help them withstand the violent floods that often occur in rainforest streams (Richards 1992).

ReproductionLittle is known about the life history of this species. Mating calls have been heard from Oct. to Mar. (Liem 1974). 86-90 large unpigmented eggs (1.9-2.5mm diameter) are laid under rocks in riffles (Richards 1993; Hero & Fickling 1996). Richards (1992) described the tadpole and noted that it is one of the few species of tadpole known to exhibit adaptations to torrent environments of Australia, including a streamlined body shape, large suctorial mouthparts and muscular tail. Tadpoles commonly overwinter in upland streams, although those hatching in early summer can metamorphose before the next autumn (Richards 1992). Invasive Species Feral pigs are a potential cause of riparian habitat damage and adult frog mortality (Richards et al. 1993). The activity of feral pigs has been recorded to have increased over the period 1989-1992 in an area previously inhabited by L. nyakalensis (Richards et al. 1993). There is very little research, however, into the impact of feral pigs on native frog populations (Richards et al. 1993).MovementsLitoria nyakalensis displays an obligate association with streams and has been observed or collected within stream banks throughout the year (McDonald & Alford 1999).

The reason(s) for the decline of L. nyakalensis are unknown. Richards et al. (1993) reject drought, floods, habitat destruction or pollution by pesticides, inorganic ions or heavy metals. The habitat of the species in the Wet Tropics has been protected since 1988, therefore habitat destruction is no longer a threat (McDonald & Alford 1999). Current research is examining the possibility that disease, such as a viral infection or chytrid fungus, may have contributed to the decline of this species (Berger et al. 1999).

The mountain mist frog or Nyakala frog (Ranoidea nyakalensis) was a species of frog in the subfamily Pelodryadinae, endemic to Australia. Its natural habitats were subtropical or tropical moist lowland forests and rivers. It was threatened by habitat loss and potentially chytrid fungus, before being declared extinct in 2022.