NSW Scientific Committee - final determination
The Scientific Committee has found that:
1. The Wedgesnout Ctenotus, Ctenotus brooksi, is a skink that reaches a total length of 10-12 cm (Cogger 2000). The species is fawn to reddish-bronze or crimson above, with stripes and variegations that vary between individuals; some bear a narrow, pale-edged black vertebral stripe from the nape to the tail.
2. The Wedgesnout Ctenotus is distributed through the arid regions of central mainland Australia (Cogger 2000). In NSW the species is known from 30 records, with 29 records from Sturt National Park and one record from Paroo-Darling National Park (Swan et al. 2004). It is likely that the Wedgesnout Ctenotus also occurs in similar habitat to the south of Sturt National Park adjacent to the South Australian border (R. Sadlier pers. comm.).
3. The Wedgesnout Ctenotus occurs in desert sand ridge habitats (Swan 1990, Cogger 2000). The species may be very specialised, as it has only be recorded from large unconsolidated sand dunes and not from the low consolidated red sand ridges that occur in the east of Sturt National Park (R. Sadlier pers. comm.). The Wedgesnout Ctenotus prefers areas of loose sand interspersed with vegetation on and near the crests of dunes (R. Sadlier pers. comm.), and it is probably restricted to habitats containing Triodia spinifex (Sadlier and Pressey 1994).
4. The Wedgesnout Ctenotus is potentially threatened by habitat disturbance in unprotected areas. Grazing by introduced herbivores within Wedgesnout Ctenotus habitat affects the density and structure of spinifex, adjacent shrubs and ground cover. This degrades Wedgesnout Ctenotus habitat and increases the risk of predation for individuals moving between patches of vegetation. Disturbance through trampling by stock also degrades Wedgesnout Ctenotus habitat by altering the soil structure and facilitating weed invasion.
5. The diets of Feral Cats, Felis catus, and European Red Foxes, Vulpes vulpes, include a significant proportion of reptilian prey (Sadlier et al. 1996). The degree of threat to the Wedgesnout Ctenotus from predation by these introduced species is unknown; this impact in concert with threats to the habitat of the Wedgesnout Ctenotus may potentially be significant.
6. The distribution of the Wedgesnout Ctenotus is severely fragmented such that local populations of the species are vulnerable to extinction via stochastic events. Although the Wedgesnout Ctenotus is known to occur within two national parks, this may not ensure the species' long-term survival in NSW.
7. In view of the above the Scientific Committee is of the opinion that the Wedgesnout Ctenotus Ctenotus brooksi (Loveridge 1933) is likely to become endangered 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: 25/06/04
Exhibition Period: 25/06/04 - 06/08/04
References:
Cogger HG (2000) 'Reptiles and amphibians of Australia.' (Reed Books: Chatswood).
Sadlier RA, Pressey RL (1994) Reptiles and amphibians of particular conservation concern in the Western Division of New South: a preliminary review. Biological Conservation 69, 41-54.
Swan G (1990) 'A field guide to the snakes and lizards of New South Wales.' (Three Sisters Productions: Winmalee)
Swan G, Shea G, Sadlier R (2004) 'A field guide to reptiles of New South Wales.' (Reed New Holland: Sydney)