Taxonomy

endemique
protegee
UICN

Common name :

Le scinque à queue en fouet du Nord Northern Whiptailed Skink

Red List Status -

Least Concern (LC) , assessed in 11/12/2017

Protected species -

in Southern Province , in Northern Province

Although Tropidoscincus boreus has a restricted range that falls within the thresholds for the threat categories, it can be locally abundant and, therefore can be regarded as secure throughout a large part of its range. It is therefore assessed as Least Concern (LC). Further research on this species is recommended to determine if the species should be placed in a threatened category if threats increase in the future, causing broader or continuous population declines.

Geographical area


Tropidoscincus boreus is endemic to New Caledonia. It is known from numerous localities across northern and central Grande Terre (northernmost localities are Mt Mandjélia in the east and the Tiébaghi massif in the west; southernmost localities are the Presqu'ile de Bogota, Mt Do and Haute Pouéo near Bourail). Recorded at elevations up to 1,100 m asl. The extent of occurrence is estimated at 7,892 km2 and the area of occupancy at 168 km2.

Population


There are no quantitative data on population size and trends for T. boreus. It is suspected to have undergone a substantial reduction in area of occupancy as a result of past clearance of forest and shrubland habitats for agriculture, logging and mining, and from wildfires. These impacts have resulted in fragmentation of the population and are on-going. This species remains locally common at many sites.

Habitat


Tropidoscincus boreus occurs in a wide range of habitats including coastal vegetation, maquis shrublands at mid- to high elevations, closed forests and montane forests. This species is diurnal, ground-dwelling and attracted to sunlight. It shelters beneath logs and rocks, and rock crevices; forages in the open or in sunlit patches on the forest floor.

Bauer and Sadlier (2000) identified females found in December as having two to three enlarged yolked ovarian follicles, and examination of samples collected since it was confirmed an egg-laying mode of reproduction (R. Sadlier pers. comm. 2010) was reported for its sister species, T. variabilis (Shea et al. 2009).

Threats


The primary threat to Tropidoscincus boreus is from loss and fragmentation of forest throughout its range and also of maquis shrubland habitats on ultramafic surfaces. This could result from a variety of factors including clearance for agriculture and afforestation, mining and wildfires. On most ultramafic massifs, mining is a particular concern as it is now undergoing a rapid expansion that threatens montane forests and high-elevation maquis shrublands, to which this species is restricted. Habitat degradation by introduced ungulates (deer and pigs) is an ubiquitous threat. In low and mid-elevation forests the introduced ant, Wasmannia auropunctatus, is a potentially serious issue as it is known to decimate lizard populations (Jourdan et al. 2000, 2001), and predation by introduced mammals such as rodents (Thibault 2017) and cats (Palmas 2017) is also of concern throughout.

As T. boreus has a relatively wide distribution across Grande Terre and has been described as common, it is likely that these threats will not have adverse impacts on this species and not cause significant declines at this time, but in some areas such as the ultramafic massifs on the north-west coast of Grande Terre they will have severe localized effect.

Conservation


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). Not listed on CITES. This species is known to occur in a number of reserves including Réserve de Nature Sauvage du Mont Panié and Réserve de Nature Sauvage du Massif de l’Aoupinié, Réserve Naturelle Terrestre du Mont Do. However, further measures should be carried out to ensure the protected areas are effective. No conservation management is currently being undertaken. Research and monitoring into the population and possible threats should also be carried out because of the relatively small distribution of this species.

Bibliography


Thibault, M., Brescia, F., Vidal, E. and Jourdan, H. 2017. Invasive rodents, an overlooked threat for skinks in a tropical island hotspot of biodiversity. New Zealand Ecological Society(41) , p.74-83.

Shea, G., Jourdan, H., Sadlier, R. and Bauer, A. 2009. Natural history of the New Caledonian whiptailed skink Tropidoscincus variabilis (Bavay, 1869) (Squamata: Scincidae).. Amphibia-Reptilia(30) , p.207-220.

Bauer, A.M. and Sadlier, R.A. 1993. Systematics, biogeography and conservation of the lizards of New Caledonia. Biodiversity Letters(1) , p.107-122.

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

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

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

Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.

Palmas, P., Jourdan, H., Rigault, F., Debar, L., De Meringo, H., Bourguet, E., Mathivet, M., Lee, M., Adjouhgniope, R., Papillon, Y. and Bonnaud, E. 2017. Feral cats threaten the outstanding endemic fauna of the New Caledonia biodiversity hotspot. Biological Conservation(214) , p.250-259.

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., Tanguy, V., Lietar, J.


Geographical distribution