Litoria daviesae (a tree frog) - vulnerable species listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the tree frog Litoria daviesae Mahony, Knowles, Foster & Donnellan 2001 as a VULNERABLE SPECIES in Schedule 2 of the Act. Listing of vulnerable species is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. Litoria daviesae is a newly described species, having recently been identified and taxonomically separated from the Glandular Frog,  L. subglandulosa (Mahony  et al. 2001). The Glandular Frog is currently listed as Vulnerable under the Act.

2. Litoria daviesae is distinguished from  L. subglandulosa by its lightly shagreened skin, its uniform golden brown to mottled brown and green colouration, and greater body length (up to 63mm). The Glandular Frog has smooth skin, is predominantly green in colour, and grows up to 50mm in length.

3. Litoria daviesae is distributed from central-eastern New South Wales to the state's lower north-east. It is known from 18 locations between the northern catchment of the Hunter River north to the catchment of the Hastings River. All records of the species are from permanently flowing streams and adjacent riparian vegetation at elevations above 400m (NSW NPWS 1994; Anstis 1997).

4. Clearing and fragmentation of native vegetation have occurred over large areas of the former and current distribution of L. daviesae. As a result, local populations appear to be restricted and isolated and are vulnerable to local extinction via demographic and environmental stochasticity. In addition, pollution of upland streams, in association with human landuse, affects  L. daviesae habitat.

5. Litoria daviesae tadpoles are possibly threatened with predation by exotic fish, including Carp  Cyprinus carpio, trout  Oncorhynchus and  Salmo species, and Plague Minnow  Gambusia holbrooki (Mahony  et al. 2001). 'Predation by  Gambusia holbrooki Girard, 1859 (Plague Minnow or Mosquito Fish) ' is listed as a Key Threatening Process under the Act.

6. Litoria daviesae is susceptible to infection by amphibian chytrid fungus,  Batrachochytrium  dendrobatidis.  Batrachochytrium 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 the east coast and Great Dividing Range, particularly upland stream-dwelling species from cooler environments.

In view of the above the Scientific Committee is of the opinion that Litoria daviesae Mahony, Knowles, Foster & Donnellan 2001 is likely to become endangered unless the circumstances and factors threatening its survival or evolutionary development cease to operate.

Proposed Gazettal date: 13/12/02
Exhibition period: 13/12/02 - 31/01/03

References 

Anstis, M. (1997). Litoria subglandulosa, Glandular Tree Frog. In 'Threatened Frogs of New South Wales: Habitats, Status and Conservation'. (Ed. H. Ehmann.) pp. 213-221. (Frog and Tadpole Study Group of New South Wales: Sydney South).

Berger, L., Speare, R. and 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).

Mahony, M., Knowles, R., Foster, R. and Donnellan, S. (2001). Systematics of the Litoria citropa (Anura: Hylidae) complex in northern New South Wales and southern Queensland, Australia, with the description of a new species.  Rec. Aust Mus. 53, 37-48.

NSW NPWS (1994). Fauna of north-east New South Wales forests. North East Biodiversity Report No. 3. New South Wales NPWS: Hurstville.