Taxonomy


Common name :
Gecko caméléon de Vieillard
Vieillard's Chameleon Gecko Red List Status -
Near Threatened (NT) , assessed in 11/12/2017Protected species -
in Southern Province , in Northern ProvinceDescription
Description:
A small species of gecko growing to a body length of 58mm and with a tail 115% that of the body; moderately broad toes; large plate like scales on the head and neck; a distinctive yellow groove running from the corner of the mouth towards the ear; and a colour pattern on the body that is typically pale with a mottling of darker markings, sometimes forming a pattern of transverse bars across the body. White underneath
Natural Distribution:
A widespread but scattered distribution throughout the main island, and also possibly present on Ile des Pin.
Distribution within Province Sud: Recorded from two locations in the north of the Province along the central ranges (Koindé, Mé Adéo) and on the coast (Poya) near the border with Province Nord, and from further south at Col de Mouirange near Mt Dore and on Ile des Pin. There is a large gap between Mt Ouin and Sarraméa where no records appear, which reflects a lack collecting in both coastal lowlands and the ranges in this area.
Distribution within Province Nord: Recorded from the south of the Province (Néaoua) including ultramafic massifs in the region of Kouaoua), north along the central ranges (Forêt Plate and Mt Aoupinié) and ultramaffic massifs on the west coast (Koniambo; Boulinda; Kopéto) and adjacent west coast lowlands (Pindaï, Nekoro, Poidala near Kone).
Habitat:
The species occurs in humid forest and sclerophyll forest habitats over a broad altitudinal range, and maquis shrubland.
Threats:
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high level of threat to maquis shrubland through repeated firing resulting in a decline in quality of habitat.
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high level of threat to humid forest and sclerophyll forest populations with high infestation levels of introduced The Little Red Fire Ant (Wasmannia auropunctata) causing significant decline in abundance.
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moderate to high level of threat to remaining sclerophyll and low elevation humid forest fragments on the west coast from clearing for ranching or agriculture resulting in loss and further fragmentation of habitat.
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moderate to high level of threat to remaining sclerophyll and low elevation humid forest fragments on the west coast from browsing by feral animals and livestock resulting in further degradation and loss of habitat.
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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.
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moderate to low level of threat to humid forest edge through repeated firing of adjacent savannah habitat resulting in a decline in area, extent and quality of habitat.
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localised but potentially high level of threat from exotic pests such as rats and cats (predation of adults, young & eggs) in heavily affected forests.
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localised but potentially intensive threat by collection for illegal trade at readily accessible sites.
Conservation Status:
Lower Risk - least concern
Eurydactylodes vieillardi occurs at 15+ locations across the entire length of the island, representing up to 10 subpopulations. Its distribution as it is known satisfies the criteria for a small distribution (area of occupancy <1,000 km2), but is likely to be recorded from additional locations with further survey work. Threats leading to a continuing decline in humid forest habitat have been identified; however, large areas of potentially suitable habitat subject only to minimal or no disturbance occur within the species range. For these reasons it is considered most appropriate to categorise Eurydactylodes vieillardi as Lower Risk - least concern. The species is not considered to be under any overall immediate threat, but sub-populations in some regions (particularly in the vicinity of mining activities) could be subject a suite of moderate to high localised threats.
Eurydactylodes vieillardi is listed as Near Threatened although its extent of occurrence is below the threshold for Vulnerable, the species is present at many more than ten locations, the population is significantly greater than 10,000 individuals and the reduction in its population size is expected to be much less than 30%. However, given the extent of ongoing clearance of low elevation habitats, the escalating threat to mid-to high elevation habitat from nickel mining, and the high level of impact by fire on reducing the size of forest patches on the central metamorphic ranges, the status of this species needs to be monitored as it could change rapidly and require re-assignment (almost meets the requirements for listing under criterion B1ab(iii)).
Geographical area
Eurydactylodes vieillardi is endemic to New Caledonia. It is widespread on Grande Terre south of the Koniambo and Tchingou massifs. Also recorded from Ile des Pins. It occurs at elevations of up to 950 m. The extent of occurrence is estimated to be 11,154 km2, and the area of occupancy at 132 km2.
Population
There are no quantitative data on population size or trends for this species, but it remains common at some locations with good maquis habitat, generally those at higher elevation. It is presumed to have suffered a substantial reduction in population size and extent from past habitat loss and degradation through clearance for agriculture, mining and afforestation, and from wildfires. This trend is ongoing with the expansion of most nickel mines within the species' range, and the continued impacts of clearance and wildfires.
Habitat
This species inhabits a very wide range of wooded habitats including maquis shrublands, sclerophyll forest, gallery forest, closed humid forest, and montane forest. It is arboreal; at least partly, possibly primarily diurnal. It appears to remain on twigs and foliage all the time rather than seeking cover during periods of inactivity.
Threats
Threats to this species include the expansion of the nickel mining industry on most of the larger ultramafic massifs within its range; further loss of habitat to clearance for agriculture, afforestation projects and wildfires; habitat degradation caused by introduced ungulates (deer and pigs); and predation by introduced mammals (rodents and feral cats) expected to exert a pressure (Palmas 2017, Thibault 2017). The introduced ant, Wasmannia auropunctata, occurs in most of the lower-elevation forests and is expected to have a detrimental impact on Eurydactylodes vieillardi populations (Jourdan et al. 2000, 2001). The distinctive chameleon-like appearance of this species and its diurnal activity make it a potential target for illegal collection and trafficking.
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 present in Parc Provincial de la Rivière Bleue and a number of other reserves in the south, including Mont Panié, Parc des Grandes Fougères and Aoupinié. No active species-specific conservation management is currently being undertaken.
Bibliography
Bauer, A.M., Jackman, T., Sadlier, R.A., Whitaker, A.H. 2009. Review and phylogeny of the New Caledonian diplodactylid gekkotan genus Eurydactylodes Wermuth, 1965, with the description of a new species. Zoologia Neocaledonica 7, Mémoires du Muséum National d’Histoire Naturelle(198) , p.13–36.
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.
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.
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.
IUCN 2021. The IUCN Red List of Threatened Species. Version 2021-2.
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.
Uetz, P. (ed.) 2017. The Reptile Database.
Bauer, A.M. and Sadlier, R.A. 2000. The Herpetofauna of New Caledonia.
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.
