Rhacodactylus auriculatus 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Reptilia Squamata Diplodactylidae

Scientific Name: Rhacodactylus auriculatus (Bavay, 1869)
Common Name(s):
English Knob-headed Giant Gecko, New Caledonian Bumpy Gecko
French Gecko Géant Cornu
Platydactylus auriculatus Bavay, 1869
Taxonomic Notes: Low levels of genetic divergence occur between the isolated populations on the northwestern ultramafic massifs and the more continuous population in the south, but these do not warrant taxonomic distinction.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2010
Date Assessed: 2009-06-30
Assessor(s): Whitaker, A.H., Sadlier, R.A. & Bauer A.M.
Reviewer(s): Böhm, M., Collen, B., Ram, M. (Sampled Red List Index Coordinating Team), Cox, N. & Tognelli, M.F.
R. auriculatus is listed as Least Concern in view of its wide distribution, presumed large population, and because the rate of population decline is not sufficient for it to be considered under a higher threat category. Even though the extent of occurrence is <20,000 km², the population is significantly greater than 10,000 individuals, the reduction in population size is expected to be <30% and the species is present at >10 locations.

Geographic Range [top]

Range Description:This species is endemic to New Caledonia. It is widespread in southern Grande Terre and present on massifs in the north-west as far north as Dôme de Tiébaghi. It appears to be restricted to ultramafic areas. Recorded up to 1,100 m asl.

The extent of occurrence is estimated at approximately 10,000 km²  and the area of occupancy at 2,000 km².

[Extent of occurrence was based on a crude measure of overall length times width of the most distant known locations (a rough measure of the line around the points), except for very widespread species where the published areas of the islands were taken.  Area of occupancy is a contraction of that rough estimate for extent of occurrence based on where habitat remains.]
Countries occurrence:
New Caledonia
Additional data:
Upper elevation limit (metres):1100
Range Map:Click here to open the map viewer and explore range.

Population [top]


Bauer and Sadlier (1993) report that this species is common. There are no quantitative data on population size or trends. It is presumed to have suffered a past reduction in population size and extent through widespread simplification of maquis as a result of wildfires, and intensive but localized habitat loss associated with mining. The species is still relatively common at many localities, although the current and projected expansion of nickel mining will result in a further reduction of the area of occupied habitat throughout its range.

Current Population Trend:Stable
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:R. auriculatus is found on the southern ultramafic block of New Caledonia and northward along the west coast and central-east coast ultramafic massifs. It inhabits humid forests, montane forests, and open and closed maquis (Bauer and Sadlier 2000). All Rhacodactylus species are excluded from agricultural and urban environments. This species is essentially nocturnal, but is sometimes active by day; primarily arboreal.  It sometimes stays in the open on branches by day but usually shelters beneath dense vegetation on the ground or in tree cavities. It forages at night on the stems of shrubs and small trees (occasionally to 15 m above ground) or less commonly on the ground.

Use and Trade [top]

Use and Trade: This species is successfully bred in captivity so the level of harvest from the wild is minimal.

Threats [top]

Major Threat(s): The close association of R.s auriculatus to ultramafic substrates means that its habitat is vulnerable to the expanding nickel mining industry. This is a particular issue on the isolated massifs in the north-west of Grande Terre where almost every population is affected, and for large areas of the Grand Sud. The maquis habitat of R. auriculatus is also at risk to wildfires and, in the south of Grande Terre, to afforestation. Other threats include habitat degradation by introduced ungulates (deer and pigs) and predation by introduced mammals (rodents, feral cats and pigs). There is also a potential impact from the introduced ant, Wasmannia auropunctata, at low-elevation sites (Jourdan et al. 2000, 2001). Although the past illegal trade in this species has now largely abated due to the ease with which it can be bred in captivity, readily accessible populations are still at risk.

Conservation Actions [top]

Conservation Actions: 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. Present in Parc Provincial de la Rivière Bleue and many reserves in Province Sud, including Pic Ningua, Forêt Cachée, Pic du Grand Kaori, Pic du Pin, Forêt Nord and Cap Ndoua (but not present in any reserves in Province Nord). No conservation management is currently being undertaken.

Citation: Whitaker, A.H., Sadlier, R.A. & Bauer A.M. 2010. Rhacodactylus auriculatus. The IUCN Red List of Threatened Species 2010: e.T176132A7185707. . Downloaded on 24 October 2017.
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