NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Loveridge's Frog, Philoria loveridgei Parker 1940, is a small, squat ground-dwelling frog that reaches a total length of approximately 30mm (Cogger 2000). Individuals range in colour from brown and reddish-brown bronze to light grey above, with a dark brown or black band along the snout; the flanks are either entirely black or have a black mark of varying size (Knowles et al. 2004). The skin is mostly smooth although some individuals have a few low warts or ridges above (Cogger 2000). Loveridge's Frog is currently listed as Vulnerable in NSW.
2. Loveridge's Frog occurs in far north-east NSW on the top of the eastern escarpment of the Great Dividing Range. A recent review of the three Philoria species in north-east NSW identified two new species, P. pughi and P. richmondensis (Knowles et al. 2004). The distributions of these new species occur in an area, which prior to taxonomic revision, was thought to be occupied by P. loveridgei. The range of Loveridge's Frog is therefore confined to a smaller area than previously thought. Records of Loveridge's Frog are almost all from National Parks and Wildlife Service estate, and are now distributed from Nightcap National Park, 20km north of Lismore, north-west to Border Ranges National Park on the NSW-Queensland border.
3. Loveridge's Frog is a habitat specialist associated with mountain streams. It inhabits boggy headwaters of streams and soaks in antarctic beech forests, rainforests and wet sclerophyll forests above altitudes of approximately 550 m (Cogger 2000; Knowles et al. 2004). Individuals burrow into loose, moist soil or moss and sit in mossy cavities on stream banks. Breeding occurs between November and January. Males construct moist, smooth-walled breeding chambers in the ground, into which jelly-encapsulated eggs are deposited. Unlike other Philoria species, liquefied jelly rather than a foam mass is deposited with the eggs and each egg contains sufficient yolk to nourish a tadpole through to the juvenile stage. The offspring of this species have no aquatic stage (Moore 1961, cited by Knowles et al. 2004).
4. Given its habitat specificity and the extent of this habitat, Loveridge's Frog is perhaps naturally restricted. However, clearing and habitat fragmentation have restricted the potential range of this species, and have isolated local populations where appropriate habitat survives. Degradation of habitat may result from disturbances to hydrological regimes and water quality, and also from trampling by domestic stock (Hines et al. 1999). Moreover, the key threatening process Anthropogenic climate change is likely to affect the extent of Philoria-preferred habitat, a threat that is not likely to be mitigated by the occurrence of habitat in reserves.
5. Loveridge's Frog is susceptible to infection by amphibian chytrid fungus, Batrachochytrium dendrobatidis, which is listed as a key threatening process in NSW. Amphibian chytrid fungus is a water-borne pathogen virulent to adults of all frog species and causes the fatal disease chytridiomycosis (Berger et al. 1999). Chytridiomycosis is responsible for the decline of many frog species from eastern Australia, particularly upland stream-associated species from cool and temperate environments. Although Loveridge's Frog is a terrestrial species, it remains susceptible to infection by its association with moist environments, where B. dendrobatidis can probably survive and grow (Berger et al. 1999). Further, breeding chambers are often aggregated on the forest floor, which increases the communicability of chytrid fungus between individuals.
6. In view of the above the Scientific Committee is of the opinion that Loveridge's Frog Philoria loveridgei Parker 1940 is likely to become extinct in nature in New South Wales unless the circumstances and factors threatening its survival or evolutionary development cease to operate.
Dr Lesley Hughes
Chairperson
Scientific Committee
Proposed Gazettal date: 29/4/05
Exhibition period: 29/4/05 - 24/6/05
References
Berger L, Speare R, Hyatt A (1999) Chytrid fungi and amphibian declines: overview, implications and future directions. In 'Declines and disappearances of Australian frogs'. (Ed. A. Campbell) pp. 23-33. (Environment Australia: Canberra).
Cogger HG (2000) 'Reptiles and amphibians of Australia.' (Reed Books: Chatswood).
Hines H, Mahony M, McDonald K (1999) An assessment of frog declines in wet subtropical Australia. In 'Declines and disappearances of Australian frogs'. (Ed. A. Campbell) pp. 44-63. (Environment Australia: Canberra).
Knowles R, Mahony M, Armstrong J, Donnellan S (2004) Systematics of sphagnum frogs of the Genus Philoria (Anura: Myobatrachidae) in eastern Australia, with the description of two new species. Records of the Australian Museum 56, 57-74.
Moore JA (1961) The frogs of eastern New South Wales. Bulletin of the American Museum 121, 149-386