Taxonomy
Common name :
Le Bavayia grêle
Gracile Bavayia Red List Status -
Near Threatened (NT) , assessed in 11/12/2017Protected species -
in Southern Province , in Northern Province
Description
Description:
A medium species of gecko growing to a body length of 72mm and with a tail 144% the length of the body; moderately broad toes; and a colour pattern on the body that is typically brown above with 5-8 darker pale-edged blotches.
Natural distribution:
southern New Caledonia.
Distribution within Province Sud: Restricted to Province Sud where it is known from several sites in closed forest south of Mt Dzumac, and from and recent records from Mt Sindoa. The sparse and scattered nature of the species distribution in the north of its range most likely reflects the lack of both survey work and suitable habitat in the region.-
Habitat:
Humid forest ranging from low to high elevation - preferring areas of forest with extensive loose rock and boulder piles on the forest floor; occasionally in maquis shrubland adjacent to humid forest habitat.
Threats:
-
potentially high level of threat to populations in humid forest with high infestation levels of the introduced Little Red Fire Ant (Wasmannia auropunctata), resulting in a significant decline in abundance.
-
potentially high level of threat to humid forest habitat on ultramafic soils through repeated firing of adjacent maquis habitat, leading to loss and degradation of the forest edge.
-
moderate to high but localised level of threat to isolated high elevation humid forest and gully forests on ultramafics through loss or degradation of habitat from activities associated with mining.
-
localised but potentially high level of threat from exotic pests such as rats and cats in heavily affected forests.
Conservation Status:
Lower Risk - near threatened
Bavayia gietiana occurs at six locations each representing an isolated sub-population - current research indicates little genetic variation between distinct geographic units. Although it is known from a number of locations in the south of the island most of these are small and isolated forest fragments Three of the locations from which it has been recorded lie within reserves, affording some degree of protection to its preferred habitat, however, introduced fire ants are present at Riviére Bleue, and the sub-population at Forêt Nord is in very close proximity to the Goro Nickel mining encampment.
The fragmented nature of its known and projected distribution in combination with a suite of threats which impact on the area, extent and/or quality of habitat, all indicate Bavayia gietiana satisfies the criteria for the species to be categorised as Lower Risk - near threatened.
Bavayia geitaina is listed as Near Threatened because it is known on around 10 widely scattered and isolated locations in the Province Sud with an extent of occurrence estimated at 806 km² and the area of occupancy at 36 km², and even if it is threatened by habitats loss and degradation from mining industry and wildfire this species occurs in multiple protected area.
Geographical area
This species is endemic to the south of Grande Terre, New Caledonia (northernmost locality is Pic Ningua). It is known from around 10 widely scattered and isolated locations (Forêt Nord, Forêt Cachée, Bois de Sud, Riviere Bleue, Mt. Koghis, Vulcain, and Pic Ningua). Occurs at altitudes ranging from 80 to 950 m asl. The extent of occurrence is estimated at 806 km² and the area of occupancy at 36 km².
Population
There are no quantitative data on population size or trends for Baviya geitaina. Bauer and Sadlier (2000) describe this species as common at Mt. Koghis. However, elsewhere throughout its range it is assumed to have suffered a substantial reduction in population size and extent from past habitat loss and degradation through clearance for agriculture, mining and afforestation (Plaine des Lacs) and wildfires. The current development of a major nickel mine in the south is resulting in on-going habitat loss on the Plaine des Lacs and in the Baie de Prony area (although the species has not been recorded outside of existing reserves in this region).
Habitat
Bavayia geitaina inhabits closed humid forests at low to mid-elevation and montane forests; occasionally in adjacent maquis shrublands. It is nocturnal, arboreal, or terrestrial on rock faces. It prefers sites with a rocky forest floor. It shelters by day beneath stones or in rock crevices and forages at night in sub-canopy vegetation or on rock faces.
Threats
The major threat to Bavayia geitaina is loss and degradation of further habitats as a result of the rapidly expanding nickel mining industry in the Grand Sud, in the Tontouta Valley and in the vicinity of Pic Ningua and Mont Çidoa. Other threats to this species include the loss or degradation of habitat from wildfires.
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). This species is present in Montagne des sources, Vallée de la Thy, Foret Nord and Rivière bleue as protected area but with no active specific conservation management currently being undertaken.
Bibliography
Bauer, A.M. and Sadlier, R.A. 2000. The Herpetofauna of New Caledonia.
Uetz, P. (ed.) 2017. The Reptile Database.
Bauer, A.M. and Sadlier, R.A. 1993. Systematics, biogeography and conservation of the lizards of New Caledonia. Biodiversity Letters(1) , p.107-122.
Wright, J.L., Bauer, A.M. and Sadlier, R.A. 2000. Two new gecko species allied to Bavayia sauvagii and Bavayia cyclura (Reptilia : Squamata : Diplodactylidae) from New Caledonia. Pacific Science(54) , p.39-55.
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.
Endemia.nc 2016. Faune et Flore de 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.
IUCN 2021. The IUCN Red List of Threatened Species. Version 2021-2.
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.