Research
Survey of the lizard fauna in sclerophyll forest at Pindaï
Study areas
Sclerophyll forest at Pindaï.
Two study areas were selected in the largest remaining dry forest fragment on the Pindaï Peninsula , which is located 250 km north of Noumèa, in the Northern Province of New Caledonia. The sampling program took place in the summer wet season, between February and April 1995, a period where reptile activity is high. Two quantitative sampling methods, sticky traps on trees to sample arboreal lizards and pitfall traps to sample ground dwelling lizards, were used at both an ant invaded and uninvaded plot. Timed visual search periods were also conducted along transects to complement the trapping program.
The lizard fauna
The lizard fauna occurring in sclerophyll forest at Pindaï consists of at least of ten species. Seven were recorded during the course of the quantitative survey including:
- three geckos; the Forest Bavayia, Bavayia cyclura; the Sclerophyll Bavayia, Bavayia excussida; and Vieillard’s Chameleon Gecko, Eurydactylodes vieillardi
- four skinks; the Common Litter Skink, Caledoniscincus austrocaledonicus; the Giant Litter Skink Caledoniscincus festivus; the Strand Litter Skink, Caledoniscincus haplorhinus; and the Pindaï Dwarf Skink Nannoscincus hanchisteus.
- two other native species, the Rough-snouted Giant Gecko, Rhacodactylus trachyrhynchus and the Green-bellied Tree Skink, Lioscincus nigrofasciolatum , were also encountered during the course of opportunistic day and night searching.
- the introduced Pacific House Gecko, Hemidactylus frenatus, was also recorded opportunistically from the edges of the invaded area.
Lizards of particular conservation significance from Pindaû: the Sclerophyll Bavayia Bavayia exsuccida, and the Pindaï Dwarf Skink Nannoscincus hanchisteus.
Of the ten species of reptiles recorded during the survey, three (Rhacodactylus trachyrhuncus, Bavayia exsuccida, and the skink Nannoscincus hanchisteus) seem to have restricted distributions and are considered of particular conservation concern. Nannoscincus hanchisteus is still known only from this location and should be regarded as a species of particular conservation significance.
Bavayia cyclura appears to be particularly abundant in sclerophyll forest at Pindaû. However, the species clearly consists of several cryptic species, the identity of which is currently under investigation by us. In this respect sclerophyll forest could be important for the conservation of species or populations within the Bavayia cyclura complex and given the high level of disturbance of lowland dry forest on the west coast.
The field survey of invaded and non-invaded plots showed a sharp decrease in the overall abundance, which was especially marked for the two dominant lizard species, Bavayia cyclura and Caledoniscincus austrocaledonicus, (respectively from canopy and ground level). Their abundance in habitat invaded by fire ants was approximately one third of that encountered in forest without invasive ants.
The ground dwelling Common Litter Skink, Caledoniscincus austrocaledonicus.
The arboreal Forest Bavayia, Bavayia cyclura.
While the results of our survey at Pindaï are preliminary in nature they indicate a significant negative interaction between lizards and the Little Fire Ant in sclerophyll habitat.
Acknowledgements
The work at Pindaï Peninsula is part of the IRD (ex ORSTOM) program "Terrestrial biodiversity in New Caledonia : faunas and ecological equilibrates".
Copyright © Australian Museum, 2002
