Taxonomy
Common name :
Marbled Gecko Red List Status -
Endangered (EN) , assessed in 11/12/2017Protected species -
in Southern Province , in Northern Province
Description
Description:
A moderately large species of gecko growing to a body length of 61mm, with a short tail up to 75% as long as the body, and a wide neck (nearly as was as the head). It has moderately broad toes with undivided subdigital scansors. The colour pattern on the body is a marbled purplish brown reticulations on light brown above and at the sides, and yellowish underneath.
Natural distribution:
Known only from the Tiébaghi massif in the far northwest of the island.
Distribution
within Province Nord: see above.
Habitat:
Lowland maquis.
Threats:
-
high but localised level of threat to lowland maquis habitat through activities associated with mining leading to a decline in area, extent and quality habitat.
-
very high level of threat to maquis shrubland from of fire leading to a decline in area, extent and quality of maquis shrubland.
-
potentially high level of threat with high infestation levels of introduced fire ants (Wasmannia auropunctata) causing significant declines in abundance of lizards.
-
localised but potentially intensive decline resulting from collection for illegal trade at readily accessible sites.
Conservation Status: Critically Endangered
Oedodera marmorata has an extremely restricted distribution (<100km2). Parts of its known distribution have already been affected by mining activities associated with the expansion of the nickel mine on Dôme de Tiébaghi, and other areas lie within the range of future activities. With increased mining activity in the areas comes the increased chance of accidental firing of the maquis habitat, and the potential introduction of the invasive Little Red Fire Ant which has been shown to have a highly deleterious affect on local lizard populations The range of existing and potentially high level threats identified above in combination with the species extremely limited distribution conservatively satisfies the criteria for this species to be categorised as Critically Endangered.
*Species restricted to closed forest habitat surrounded by maquis shrubland are highly susceptible to catastrophic impact of wildfires, and require pro-active conservation management to deal with this potential threat.
Oedodera marmorata is listed as Endangered because it is present at only two locations, with an extent of occurrence and area of occupancy estimated at 12 km2 and a continuing decline in its population, area of occupancy, and extent and quality of its habitat due to a variety of threats.
Geographical area
This species is endemic to Province Nord, New Caledonia. It is known from only two close localities in Koumac: one on the dôme of Tiébaghi and one on the adjacent lowlands. It occurs at elevations between 10 and 400 m. The extent of occurrence and the area of occupancy are estimated at 12 km2.
Population
There are no quantitative data on population size or trends for this species. There are no known localities where the species is common. It is presumed to have suffered a reduction in population size and extent from past habitat loss and degradation through clearance for agriculture and mining, and from wildfires.
Habitat
This species occurs in maquis shrublands and closed forest remnants. It is nocturnal and arboreal. During the day, it shelters beneath loose bark or in tree holes and crevices, and forages at night on twigs and foliage to canopy height.
Threats
The main threats to Oedodera marmorata are the habitat loss and degradation from the current expansion of the nickel mine on Dôme de Tiébaghi and from the expansion of urbanization and tourism on Paagoumène/Creek à Paul. Other major threats on this species are the habitat loss and degradation from wildfire. There is an on-going habitat degradation from introduced ungulates (deer and pigs). Rodents and feral cats are present at all known locations for Oedodera marmorata and they are expected to exert a predation pressure (Palmas 2017, Thibault 2017). The highly invasive Asian Gecko Hemidactylus frenatus is currently spreading into the maquis habitat occupied by Oedodera marmorata and may be competing with it and the invasive ant, Wasmannia auropunctata, is abundant in closed forest habitats (Jourdan 2001).
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). This species is not present in any protected area and no conservation species-specific management is currently being undertaken.
Bibliography
L'Huillier L.; Jaffré T. and Wulff A. 2010. Mines et Environnement en Nouvelle-Calédonie : les milieux sur substrats ultramafiques et leur restauration.
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.
Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.
Hély-Alleaume 2012. INC : Incendies et biodiversité des éco-systèmes en Nouvelle-Calédonie.
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.
Bauer, A.M., Jackman, T., Sadlier, R.A. and Whitaker, A.H. 2006. A new genus and species of diplodactylid gecko (Reptilia: Squamata: Diplodactylidae) from northwestern New Caledonia. Pacific Science(60) , p.125–135.
Uetz, P. (ed.) 2017. The Reptile Database.
IUCN 2021. The IUCN Red List of Threatened Species. Version 2021-2.
Jourdan, H., Brescia, F. and Vidal, E. 2014. Programme R_Mines.Impact des espèces invasives sur les communautés de reptiles des massifs miniers.
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.
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): Tanguy, V., Warimavute, G., Lietar, J.