White's skink (Liopholis whitii) population, Broken Hill Complex Bioregion - endangered population listing
The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list White's Skink, Egernia whitii (Lacépède, 1804) population in the Broken Hill Complex Bioregion as an ENDANGERED POPULATION on Part 2 of Schedule 1 of the Act.
This species is now known as Liopholis whitii Lacépède, 1804 [NSW Government Gazette No. 183, 27 December 2013, Page 6019].
NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. Egernia whitii is a ubiquitous medium sized skink that is abundant across a variety of habitats (mostly rocky habitats) in eastern Australia. It is a variable species which occurs in two main colour morphs. In the most common morph, the ground colour is dark brown with paler mid-vertebral and shoulder stripes. A series of pale spots, forming a broken line, are found between the stripes. The flanks are paler than the back and are speckled with both darker and lighter spots. In the less common morph, the upper surface is pale brown, with few or no markings. The shoulder area has numerous darker spots and blotches. It has a snout-vent length of up to 100 mm (Cogger 2000).
2. Egernia whitii is not listed on Part 1 of Schedule 1 of the Act and thus populations of E. whitii are eligible for consideration for inclusion on Part 2 of Schedule 1 of the Act.
3. Egernia whitii is known to occur in South Australia, Tasmania, Victoria, NSW and Queensland (Chapple 2003). A disjunct population of E. whitii occurs in Broken Hill Complex Bioregion in western NSW (Foster 1993, Swan and Foster 2000), approximately 600 km from the closest other population (Chapple et al. 2005). The Broken Hill Complex Bioregion population has been reproductively isolated from other populations of E. whitii sufficiently long for it to have undergone morphological differentiation, but it can be assigned to E. whitii using molecular techniques (Chapple et al. 2005). It is most closely related to populations in Victoria and South Australia (Chapple and Keogh 2004).
4. The Broken Hill Complex Bioregion population is very small, and is thought to consist of fewer than 10 individuals (Foster 1993, Swan and Foster 2000). Observations over consecutive years have confirmed the small population size (Swan and Foster 2000).
5. The Broken Hill Complex Bioregion population has a very restricted distribution, having been found only within a single gorge within Mutawintji National Park (Foster 1993, Swan and Foster 2000). It is thought this is a relict population from the late Tertiary and Pleistocene period, when Australia was less arid (Chapple et al. 2005).
6. The restricted distribution and small population size makes this population vulnerable to extinction from stochastic events.
7. In view of the above the Scientific Committee is of the opinion that White's Skink, Egernia whitii (Lacépède, 1804) population in the Broken Hill Complex Bioregion is facing a high risk of becoming extinct in nature in NSW and is of conservation value at the State or regional level for the following reason: it is disjunct or near the limit of its geographic range.
Dr Lesley Hughes
Chairperson
Scientific Committee
Gazettal Date: 18/11/05
Exhibition Period: 18/11/05 - 13/01/06
References:
Chapple DG (2003) Ecology, life history, and behaviour in the Australian scincid genus Egernia, with comments on the evolution of complex sociality in lizards. Herpetological Monographs 17, 145-180.
Chapple DG, Keogh JS (2004) Parallel adaptive radiations in arid and temperate Australia: molecular phylogeography and systematics of the Egernia whitii (Lacertilia: Scincidae) species group. Biological Journal of the Linnean Society 83, 157-173.
Chapple DG, Keogh JS, Hutchinson MN (2005) Substantial genetic substructuring in southeastern and alpine Australia revealed by molecular phylogeography of the Egernia whitii (Lacertilia: Scincidae) species group. Molecular Ecology 14, 1279-1292.
Cogger H. 2000 Reptiles and Amphibians of Australia. (Reed Books: Sydney).
Foster R (1993) A significant range extension of Egernia margaretae personata? Herpetofauna 23, 35-36.
Swan G, Foster R (2000) Confirmation of occurrence of the skink Egernia margaretae in western New South Wales. Herpetofauna 30, 48-49.