Simiscincus aurantiacus is found at seven localized sites. Apart from Parc Provincial de la Rivière Bleue, the species is present in a few small reserves, all of which are impacted by development and mining in surrounding areas, as well as by invasive species. Most of the extent of occurrence remains unprotected. Therefore, it is listed as Vulnerable.

Geographical area

This species is endemic to Province Sud, New Caledonia. It is known from eight localities across southern Grande Terre. It occurs at elevations between 150 and 500 m. The extent of occurrence is estimated at 543 km² and the area of occupancy at 52 km².

Population

There are no quantitative data on population size and trends for this species. However, it is expected to have undergone a reduction in area of occupancy and total population size as a consequence of the widespread loss of closed forest and canopied maquis habitat that has resulted from the recurrent wildfires in the adjacent maquis shrublands. Some areas of habitat may also have been lost to mining and logging. These impacts are ongoing. This species is rare (or very elusive) at all the localities it has been found.

Habitat

This species inhabits low to mid-elevation closed humid forests and maquis para- and pre-forest. Its activity period is unknown (possibly nocturnal), cryptozoic; terrestrial. It shelters beneath logs, rocks and deep leaf litter, and in soil crevices. It usually forages in cover or in the open in low-light situations.

Threats

The most serious threat to Simiscincus aurantiacus is the further loss and fragmentation of habitat through the clearance of closed forests and canopied maquis. This risk is greatest for the population on the Goro Plateau which is directly threatened by the exploitation of a very large opencast mine. However, the two populations in reserved forest remnants on the nearby Monts Néngoné Range are at risk of degradation from the proximity of the mine development, particularly that in the Forêt Nord reserve as it immediately adjoins the coal-fired nickel smelter. Wildfires in maquis shrublands are also a threat to forest margins. Elsewhere in the Grand Sud closed forest habitats are under threat from afforestation. Introduced ungulates (deer and pigs) threaten habitat quality, particularly by damaging the litter layer and disrupting cover (such as rocks and logs) and through opening the forest and lowering humidity. The introduced ants Wasmannia auropunctata and Anoplolepis gracilipes, which are both present in the Grand Sud, are expected to have an adverse impact. Introduced mammals (rodents and pigs) are potential predators.

Conservation

This species is protected in Province Nord under Code de l'environnement de la Province Nord (Délibération No. 306-2008/APN, 24 October 2008) and in Province Sud under Code de l'environnement de la Province Sud (Délibération No. 25-2009/APS, 20 March 2009). It is present in Parc Provincial de la Rivière Bleue and Réserve de Forêt Nord. No specific conservation management is being undertaken.

Bibliography

Jourdan, H., Sadlier, R.A. and Bauer, A.M. 2001. Little Fire Ant Invasion (Wasmannia auropunctata) as a threat to New Caledonian lizards: Evidences from a sclerophyll forest (Hymenoptera: Formicidae). Sociobiology(38) , p.283-301.

Sadlier, R.A. and Bauer, A.M. 1997. A new genus and species of lizard (Reptilia: Scincidae) from New Caledonia, southwest Pacific.. Pacific science(51) , p.91-96.

Jourdan, H., Sadlier, R.A. and Bauer, A.M. 2000. Premières observations sur les conséquences de l’invasion de Wasmannia auropunctata 1863 (Roger) sur les prédateurs supérieurs dans les écosystèmes Néo-calédoniens. Actes des collectes insectes sociaux(13) , p.121-126.

Bauer, A.M. and Sadlier, R.A. 2000. The Herpetofauna of New Caledonia.

IUCN 2021. The IUCN Red List of Threatened Species. Version 2021-2.

Uetz, P. (ed.) 2017. The Reptile Database.

Experts

Assessor(s): Sadlier, R., Bauer, A., Jourdan, H., Astrongatt, S., Deuss, M., Duval, T., Bourguet, E., McCoy, S., Bouteiller, A., Lagrange, A.

Reviewer(s): Cox, N.

Contributor(s): Whitaker, A.

Facilitator(s): Warimavute, G., Lietar, J., Tanguy, V.