Research

Gracile Burrowing Skink Graciliscincus shonae

Conservation status: Vulnerable

Description: A small, elongate species of skink growing to a body length of 42mm, with short limbs, a stout tail up to 125% of the body, a broad, rounded snout, and moderately smooth body scales. Colouration is brown with fine, dark markings forming a pattern of broken lines down the body. Ventral surface is pale with regular dark markings.

Natural distribution: Restricted to southern New Caledonia. It is a fossorial (adapted for digging or burrowing) species inhabiting the subsurface soil and litter layer in closed forest habitat.

Distribution within Province Sud: Known from four locations in the very south of the island, as far north as Mt Dzumac.

Threats:

• potentially high level of threat to isolated high elevation closed forest populations on ultramafic soils through activities associated with mining (particularly gully forests affected by mining spoil), leading to a decline in area, extent and quality habitat
• moderate to potentially high level of threat to closed forest populations with high infestation levels of introduced Fire Ants (Wasmannia auropunctata), causing significant decline in abundance
• moderate level of threat to closed forest populations through repeated firing of adjacent maquis shrubland, leading to a decline in quality of habitat
• localised but moderate to high level of threat from exotic pests such as pigs (predation of adults, young and eggs; localised disturbance of shelter sites)

Maquis shrubland - low and heath-like vegetation
Ultramafic - soils that are dominated by minerals high in magnesium and iron, and which tend to be dark-coloured rather than pale.

Conservation status: Graciliscincus shonae is a closed forest dependant species known from four locations representing at least three separate sub-populations in the south of the island. At three of the localities from which it has been recorded G. shonae is only represented by a single specimen. However, given the difficulty in reliably relocating this species at Mt Koghis, an area that has been searched repeatedly, it is not surprising the species has not turned up more often during opportunistic collecting at other less frequently sampled sites. It is possible G. shonae will be recorded from other areas of closed forest habitat in the far south of the island, but the overall extent of its distribution is likely to remain low. Its' small distribution in combination with several high levels of threat indicate the species is at risk, and it is here conservatively classified as Vulnerable. It could be placed at a higher level of threat if declines in the area, extent and/or quality of habitat persist.

Because it is restricted to close forest habitat the threats identified will impact on the extent and quality of habitat at a local level. It is also possible the species could show levels of population sub-structuring. Identification of these broader geographical units and preservation of the species across them is an important issue for conservation of biodiversity.

Future research required:

• undertake targeted survey work to more comprehensively document the species overall distribution
• research to identify distinct geographic units
• assess the extent of decline in area and/or quality of forest habitat in which it occurs

Copyright © Australian Museum, 2002