NSW Scientific Committee - final determination
The Scientific Committee found that:
1. Günther's Skink, Cyclodomorphus branchialis, is currently listed as Vulnerable under the Act. Taxonomic revision has since divided C. branchialis into five separate species, two of which are known from New South Wales (NSW) (Shea and Miller 1995): C. venustus; and C. melanops, with three subspecies. Cyclodomorphus melanops elongatus is the only C. melanops subspecies known to occur in NSW.
2. Cyclodomorphus. melanops elongatus, is distributed from southern Western Australia, through South Australia to the south-western corner of NSW. Two outlying populations occur in the Northern Territory and northern South Australia, and in central-western Queensland. The NSW population of C. melanops elongatus represents the eastern extent of the subspecies in Australia and it appears to be isolated from other populations of the subspecies in South Australia and Western Australia. Shea and Miller (1995) recognised scale pattern differences between individuals from NSW and specimens from further west, which may reflect this isolation.
3. Cyclodomorphus melanops elongatus is usually light greyish-green above (Shea and Miller 1995). Individuals reach between 160-180mm in total length.
4. Cyclodomorphus melanops elongatus is restricted to mallee woodlands with a spinifex, Triodiasp., understorey (Sadlieret al. 1996). The subspecies is entirely dependent on spinifex clumps for shelter and foraging sites. Individuals are usually found within relatively large, mature spinifex clumps in areas that are not frequently burnt.
5. Cyclodomorphus melanops elongatus has been recorded from three locations including Tarawi Nature Reserve and Mallee Cliffs National Park. However, given their relative size and isolation, these conservation areas may not ensure the species' survival in NSW.
6. Degradation and loss of Cyclodomorphus melanops elongatus habitat occurs in association with land use. Grazing by both livestock and feral species within mallee-spinifex habitat affects the density and structure of spinifex. Cattle, goats and sheep graze spinifex seed heads, and in the process trample the clumps (Maher et al. 1995). Grazing also affects the density of adjacent shrubs and ground cover (which offer shelter for individuals moving between spinifex clumps). Disturbance through trampling by stock degrades the soil structure and facilitates weed invasion.
7. Alteration of natural fire regimes, in association with landuse, directly affects Cyclodomorphus melanops elongatus habitat. Pastoralists utilise fire to reduce the density of spinifex and promote the growth of vegetation that is more palatable to stock (Maher et al. 1995). However, such practises may be too frequent and non-patchy, reducing the amount of habitat and affecting the ability of individuals to recolonise burnt areas (Masters 1996).
8. In view of the above the Scientific Committee is of the opinion that Cyclodomorphus melanops elongatus (Werner, 1910) 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.
Associate Professor Paul Adam
Chairperson
Scientific Committee
Proposed Gazettal date: 12/09/03
Exhibition period: 12/09/03 - 24/10/03
References
Maher, M., Norris, D., Ridge, T. and Robinson, M. (1995). 'The Ledknapper Spinifex: Its People, Plants and Animals.' (Land Information Centre: Bathurst.)
Masters, P. (1996). The effects of fire-driven succession on reptiles in spinifex grasslands at Uluru National Park, Northern Territory. Wildlife Research 23, 39-48.
Sadlier, R.A., Pressey, R.L. and Whish, G.L. (1996). Reptiles and amphibians of particular conservation concern in the Western Division of New South Wales: distributions, habitats and conservation status. Occasional Paper 21. (NSW National Parks and Wildlife Service: Hurstville.)
Shea, G.M. and Miller, B. (1995). A taxonomic revision of the Cyclodomorphus branchialis species group (Squamata: Scincidae). Records of the Australian Museum 47, 265-325.