Research

Orange-bellied Burrowing Skink Simiscincus aurantiacus

Conservation status: Endangered

Description: Simiscincus aurantiacus is a moderately large species of scincid lizard (102mm snout-vent length) characterised by an elongate body, broad, blunt snout, and bold coloration featuring a contrasting light dorsal and dark upper lateral surface and bright orange/yellow ventral surface with black markings on the throat.

Natural distribution: Known only from the south of New Caledonia.

Distribution within Province Sud: Recorded from a single location, Mt Koghis, on the Koghis range behind Noumea.

The species is known from a single individual collected at mid elevation (500 m) on the western slopes of Mt Koghis beneath a small rock on a rocky hillslope in closed forest habitat. Upon being uncovered it moved quickly, with a sliding motion, through cracks and crevices in the soil beneath the rock. A tentative observation of a second individual was at the same location on another occasion. The area has been opportunistically surveyed by the authors on a number of occasions over an extensive period of time.

Threats:

• 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.

Conservation status: Simiscincus aurantiacus is a closed forest dependant species with highly specific microhabitat requirements and an extremely restricted distribution (<100km2). Moist forest species with a specialised biology are highly susceptible to catastrophic impact from external forces such as the introduction of wildfires, exotic pests, and modification to humidity and soil moisture levels, and require pro-active conservation management that anticipates potential threats. It possibly has a broader distribution, but because of its unusual biology it is only likely to rarely be encountered using conventional survey techniques.

The species reliance upon closed forest habitat, the small size of closed forest habitat at the only known location, its proximity to urban settlement, and the impact on that forest associated use for recreation, in combination pose a threat to its long term security. For these reasons it is categorised as Endangered, but could be placed at a high category of risk should the area of occurrence, and extent and/or quality of habitat continue to decline.

Future research required:

• undertake targeted survey work to determine the species overall distribution in the region

Copyright © Australian Museum, 2002