Philoria richmondensis (a frog) - endangered species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the frog Philoria richmondensis Knowles, Mahony, Armstrong and Donnellan, 2004 as an ENDANGERED SPECIES in Part 1 of Schedule 1 of the Act. Listing of endangered species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Philoria richmondensis Knowles, Mahony, Armstrong and Donnellan, 2004 is a newly described frog species, having recently been identified from within the north-east NSW  Philoria complex, which includes the Mountain Frog,  P. kundagungan, Loveridge's Frog,  P. loveridgei, and the Sphagnum Frog,  P. sphagnicolus. Each of the three latter species is currently listed as Vulnerable under the Act.

2. Philoria richmondensis was separated from other species of  Philoria on the basis of mitochondrial DNA sequence and allozyme variation (Knowles  et al. 2004). The species has a robust, pear-shaped body that reaches a total length of approximately 28 mm (Knowles  et al. 2004). Individuals vary in colour from yellow, red or maroon above, and are occasionally light tan or bronze. A facial stripe extends from the snout, through the eye to the base of the forelimb. Most specimens have black patches on the lower back, which occasionally join at the midline to form an arrow-shape pointing to the head.

3. Philoria richmondensis occurs in far north-east NSW on the top of the eastern escarpment of the Great Dividing Range. Confirmed records of  P. richmondensis are limited to only three voucher specimens from three national parks, approximately 40km north-west of Casino (Knowles  et al. 2004): Richmond Range, Toonumbar and Yabbra National Parks. A small number of as yet unconfirmed voucher records from the latter two national parks are also likely to be specimens of  P. richmondensis.

4. Philoria richmondensis is a habitat specialist associated with mountain streams. It inhabits boggy headwaters of streams and soaks in antarctic beech forests, rainforest and wet sclerophyll forests above altitudes of approximately 550m (Knowles  et al. 2004). Individuals burrow into loose, moist soil or moss and sit in mossy cavities on stream banks. Breeding occurs from at least October to December. Males construct water-filled breeding chambers in the ground, into which jelly-encapsulated eggs are deposited in a foam mass (Knowles  et al. 2004). Each egg contains sufficient yolk to nourish an embryo through to the juvenile stage, and like other species of  Philoria,  P. richmondensis tadpoles complete their entire development within these nests.

5. Given its habitat specificity and the extent of this habitat, P. richmondensis 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.

6. Philoria richmondensis 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  P. richmondensis 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.

7. In view of the above the Scientific Committee is of the opinion that Philoria richmondensis Knowles, Mahony, Armstrong and Donnellan, 2004 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).

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