Taxonomy
Common name :
Eurydactyle à grandes écailles, gecko-caméléon à larges écailles
Large-scaled Chameleon Gecko Red List Status -
Near Threatened (NT) , assessed in 11/12/2017Protected species -
in Southern Province , in Northern Province
Description
Description:
A small species of gecko growing to a body length of 53mm and tail 100-107% that of the body. It has moderately broad toes and large, regular plate-like scales on the head and neck, there is a distinctive groove running from the corner of the mouth to beyond the ear opening, the skin of the groove being yellow in colour. The colour pattern on the body is typically pale with a mottling of darker markings, sometimes forming a pattern of transverse bars across the body. White underneath.
Natural distribution:
Restricted to southern New Caledonia.
Distribution within Province Sud: Recorded from Pic Ningua south to Prony.
Habitat:
Maquis shrubland and closed forest.
Threats:
-
high level of threat to closed forest populations with high infestation levels of introduced fire ants (Wasmannia auropunctata) causing significant decline in abundance.
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moderate to high level of threat to maquis shrubland through repeated firing leading to a decline in quality of habitat.
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moderate to high but localised level of threat to isolated humid forest and gully forests on southern ultramafics through loss or degradation of habitat from activities associated with mining.
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potentially moderate level of threat to populations inhabiting maquis shrubland on ultramafic soils through activities associated with mining leading to a decline in area, extent and quality habitat.
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generally low level of threat from exotic pests such as rats and cats (predation of adults, young & eggs).
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localised but potentially intensive threat by collection for illegal trade at readily accessible sites.
Conservation Status: Vulnerable
Eurydactylodes symmetricus is recorded from five locations in the south of Grande Terre, each potentially representing an isolated sub-population. The species overall distribution as it is known is small (area of occupancy 500km2), but it is likely to be recorded from additional locations with further survey work. Several threats leading to a continuing decline in area and extent of maquis and forest habitat have been identified, in particular the affect of fire on maquis shrubland (loss of diversity) leading to simplification of the habitat and the potential impact of introduced fire ants on populations in closed forest habitats and Infestations of crazy ants on populations in maquis shrubland.
The species overall small distribution in combination with a suite of existing and potential threats that affect the area, extent and/or quality of habitat occupied by the species, indicate Eurydactylodes symmetricus satisfies the criteria to be categorised as Vulnerable.
Eurydactylodes symmetricus has been assessed as Near Threatened. Even though the extent of occurrence and area of occupancy are below the threshold values for Vulnerable. Its extent of occurrence is estimated at 2,035 km2, it is known from eleven disjunct locations and, although not abundant, is widespread in every habitat in these locations. However, because of the threats this species faces from habitat loss and degradation and invasive species, a Near Threatened status is appropriate as it almost qualifies for listing under criterion B1ab(iii).
Geographical area
Eurydactylodes symmetricus is restricted to the southern part of Grande Terre (northernmost confirmed location is Pic Ningua). It appears to be allopatric with E. occidentalis but apparently sympatric with E. vieillardi. Recorded from 20 to 1,050 m asl. The extent of occurrence is estimated at 2,035 km2 and the area of occupancy at 64 km2.
Population
There are no quantitative data on population size or trends, but nowhere is Eurydactylodes symmetricus as abundant as the other Eurydactylodes species. It is presumed to have suffered a substantial reduction in population size and extent from past habitat loss and degradation, primarily through wildfires but also caused by the development of a major nickel mine in the south who resulting in the continuing loss of substantial areas of habitat in the vicinity of Baie de Prony and the Plaine des Lacs.
Habitat
Occurs in a range of wooded habitats including tall maquis shrublands (maquis arbustif and maquis paraforestier), and closed humid 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
In the Grand Sud, the greatest single threat to Eurydactylodes symmetricus is the projected expansion of the nickel mining industry which could ultimately result in the loss of large areas of habitat. Other threats to this species include habitat loss or degradation from wildfires, predation by introduced mammals, rodents (Thibault 2017) and feral cats (Palmas 2017), and the impacts of the introduced ant, Wasmannia auropunctata, which is known to have a detrimental impact on lizard populations (Jourdan et al. 2000, 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). Not listed on CITES. This species is present in Parc Provincial de la Rivière Bleue and a number of other reserves in the south including Pic Ningua, Pic du Grand Kaori and Forêt Nord. It is important that the protected areas are properly managed. Surveys of this species, as well as monitoring of invasive fire ants and habitat decline should be carried out.
Bibliography
Uetz, P. (ed.) 2017. The Reptile Database.
IUCN 2021. The IUCN Red List of Threatened Species. Version 2021-2.
Sadlier, A.M. and Bauer, R.A. 2006. Conservation Status of Endemic New Caledonian Lizards: an assessment of the distribution and threats to the species of lizard endemic to New Caledonia, including species accounts.
Endemia.nc 2016. Faune et Flore de Nouvelle-Calédonie.
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.
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.
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.