Research
Panié Litter Skink Caledoniscincus orestes (southern population)
Panié Litter Skink Caledoniscincus orestes, female (southern population).
Panié Litter Skink Caledoniscincus orestes, male (southern population).
Conservation status: Endangered
Description: A moderately small, surface active species of skink growing to a body length of 65mm, with well developed limbs, and a tail 130% the length of the body. Colouration differs markedly between males and females. Males are dark overall, with pale markings down the middle of the body forming a vertebral stripe, whereas females and young of both sexes are typically two-toned being lighter above and dark at the sides, with irregular pale vertebral markings. The ventral surface of males is orange and that of females yellowish. The scales of the body have three distinct ridges or keels running along each scale.
Natural distribution: Central ranges.
Distribution within Province Sud: Recorded from Mt Sindoa, Plateau de Dogney, and Table Unio all in the north of the Province.
Distribution within Province Nord: Known from Me Adeo in the far north of the Province.
Threats:
- high level of threat to isolated closed forest populations on ultramafic soils of the central ranges (Me Adeo and Mt Sindoa) through activities associated with mining (particularly gully forests affected by mining spoil), leading to a decline in area, extent and quality habitat
- moderate to high level of threat to closed forest edge through repeated firing of adjacent maquis shrubland habitat, leading to a decline in area, extent and quality of habitat
- potentially high level of threat with high infestation levels of introduced Fire Ants (Wasmannia auropunctata) at lower elevation sites in both the north-eastern and central ranges
- moderate level of threat to closed forest edge through repeated firing of adjacent savannah habitat
Maquis shrubland - low and heath-like vegetation
Ultramafic - solis that are dominated by minerals high in magnesium and iron, and which tend to be dark-coloured rather than pale.
Conservation status: The species distribution in the central ranges is small (area of occupancy <500 km2), it is known from four locations, each of which represents an isolated sub-population. These sub-populations are likely to be highly vulnerable to disturbance, and are threatened by the presence or potential for mining and/or the impact of frequent firing on the forest edge. Both these threats result in a continuing decline in area and extent of occurrence, and decline in quality of habitat. The sub-population on Me Adeo occurs partially on an ultramafic peak, with closed forest habitat above 500m in elevation on only part of the peak, the remainder being maquis shrubland. Recent survey work (Conservation International, Maruia Society, and Province Nord Provincial Government, 1998) identified repeated firing leading to encroachment on the high elevation forest (800m and above) by shrubland as a major threat to this sites biodiversity value. Burning is also likely to have played a part in the reduction of closed forest habitat to patches on Plateau de Dogney, and Mt Sindoa. The situation at Table Unio is unknown.
The species relictual distribution, in combination with several high levels of threat indicates it is at high level of risk, and it is most appropriately classified as Endangered. In particular populations of C. orestes in high elevation closed forest on ultramafic soils (Mt Sindoa) could be highly threatened at a local level by any proposed mining activities of areas with closed forest habitat. Species restricted to isolated remnant forest at high elevation are highly susceptible to catastrophic impact from external forces such as the introduction of exotic pests and wildfires, and require pro-active conservation management that anticipates potential threats.
Future research required:
- undertake targeted survey work to more comprehensively document the species overall distribution in the central ranges
- assess the extent of decline in area and/or quality of forest habitat in which it occurs, particularly with regard to the impact of fire on the forest edge
- assess the potential impact of the Fire Ant on the different populations
Copyright © Australian Museum, 2002
