Taxonomy
Common name :
Le Bavayia à bandes claires
Pale-Striped Bavayia Red List Status -
Near Threatened (NT) , assessed in 11/12/2017Protected species -
in Southern Province , in Northern Province
Description
Description:
A small relatively stout species of gecko growing to a body length of 50mm and with a short tail 110% that of the body; moderately broad toes; and colour pattern on the body that is typically brown to light olive-green with a broad but usually obscure lighter vertebral stripe, but some individuals being almost uniform and with no obvious stripe.
Natural Distribution:
southern New Caledonia.
Distribution within Province Sud: Restricted to Province Sud and ranging in distribution from the Plaine des Lacs north to Mt Ouin.
Habitat:
Humid forest on the Plaine des Lacs, occasionally occurring in open maquis shrubland; low-high elevation humid forest on chaine centrale.
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 patches and canopied maquis habitat on ultramafic soils through repeated firing of adjacent maquis habitat, leading to loss and degradation of the forest and canopied maquis edge.
-
moderate to high but localised level of threat to humid forest patches, gully forests and isolated patches of canopied maquis shrubland on ultramafics through loss or degradation of habitat from activities associated with mining.
-
localised but potentially high level of threat potentially high level of threat from exotic pests such as rats and cats (predation of adults and young) in heavily affected forests.
Conservation Status:
Lower Risk - near threatened.
Bavayia septuiclavis is known from more than 15 locations over the south of the island, a number possibly representing isolated sub-populations in humid forest patches on the Plaine des Lacs. Because of its relatively broad distribution the species does not satisfy the criteria required to place it at a higher level of threat - it is also likely to be recorded from additional locations with further survey work. It occurs mainly in humid forest habitat, but has also been recorded from small, isolated patches of canopied maquis shrubland, and less commonly in open maquis shrubland on the Plaine des Lacs - humid forest and canopied maquis habitat in the region is highly fragmented, often small in size, and subject to a range of potential threats. Increased fire frequency in maquis shrubland is also likely to result in extensive areas of unsuitable habitat, further isolating populations in patches of humid forest and canopied maquis.
The fragmented nature of much its known habitat and projected distribution in combination with a suite of threats which impact on the area, extent and/or quality of habitat, all indicate Bavayia septuiclavis satisfies the criteria for the species to be categorised as Lower Risk - near threatened.
Bavayia septuiclavis is listed as Near Threatened because the extent of occurrence is well below the threshold under criterion B and the populations in the south are highly fragmented and isolated and at high risk from wildfires and the expanding mining industry. However, this species does not qualify for a threatened category yet because it is known from a relatively large number of locations and is abundant at some of them, and there is extensive potential habitat along the main ranges (almost qualifies for listing under criterion B1ab(iii)+2ab(iii)).
Geographical area
Bavayia septuiclavis is endemic to Province Sud, New Caledonia. It occurs in the southern portion of Grande Terre (northernmost locality is Mt Vulcain, Tontouta Valley). It occurs at elevations between 10 m and 900 m. The extent of occurrence is estimated at 1,542 km2, and the area of occupancy at 156 km2.
Population
There are no quantitative data on population size or trends for Bavayia septuiclavis. Within its known range there has been extensive loss of humid forest and modification to maquis habitats from a wide range of causes including wildfires and clearance for occupation, agriculture, afforestation, logging and mining. As a result, away from the main ranges, the remaining populations are fragmented and localised. The species is locally abundant at many sites.
Habitat
Bavayia septuiclavis inhabits closed humid forests, tall canopied maquis (maquis paraforestier), and on the Plaine des Lacs adjacent areas of maquis shrublands, it also has been recorded from montane forests. This species is nocturnal and arboreal, sheltering by day beneath stones, logs and leaf litter and foraging at night in sub-canopy trees and shrubs.
Threats
The loss of closed forest habitat is the greatest threat to Bavayia septuiclavis and in the southern part of its range this will result from the rapidly expanding nickel mining industry in the Grand Sud. Loss of habitat to mining activities is also a problem in the Tontouta Valley. Other threats include the loss or degradation of habitat from wildfires and the effects of introduced ungulates (deer and pigs), and predation by introduced mammals as rodents (Thibault 2017) and feral cats (Palmas 2017). At low elevation sites the occurrence of the introduced ant, Wasmannia auropunctata, in closed forest habitats is expected to have a detrimental impact as it has been shown to decimate lizard populations (Jourdan et al. 2000, 2001). An additional threat in the south is the increasing area of indigenous vegetation being converted to exotic forestry.
Conservation
Protected in Province Nord under Code de l'environnement de la Province Nord (Délibération No. 306-2008/APN, 24 Octber 2008) and in Province Sud under Code de l'environnement de la Province Sud (Délibération No. 25-2009/APS, 20 March 2009). Bavayia septuiclavis is present in Parc Provincial de la Rivière Bleue and a number of other reserves in the south, including Mont Koghis, Forêt Cachée, Pic du Pin, Pic du Grand Kaori and Forêt Nord. No active conservation management is being undertaken.
Bibliography
Uetz, P. (ed.) 2017. The Reptile Database.
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.
Sadlier, R.A. 1989. Bavayia validiclavis and Bavayia septuiclavis, two new species of gekkonid lizard from New Caledonia. Records of the Australian Museum(40) , p.365–370.
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.
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.
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.
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): Lietar, J., Tanguy, V., Warimavute, G.