Sulawesi, Indonesia, is a large equatorial island with a rich and diverse herpetofaunal assemblage. More than 110 reptile and 46 frog species have been recorded from the island to date, many of which are endemic (Iskandar and Tjan 1996). However, despite this high level of endemicity and the biogeographical significance of the region, relatively few surveys have been undertaken of the herpetofauna of Sulawesi and associated smaller islands. Therefore these figures are likely to be conservative estimates of the species richness of Sulawesi. Approximately half of the frog taxa known from Sulawesi have been discovered in the past 15 years, and many are yet to be formerly described. New reptile species have also been discovered in recent years (Iskandar and Tjan 1996). In addition, the systematics of several other reptile groups requires further resolution, and the status of a number of species in the region requires clarification (Iskandar and Tjan 1996). The conservation status of many poorly-known taxa is also unclear.

A sound knowledge of species distributions habitat associations, and their systematics is essential for effective biodiversity conservation planning and management. Consequently there is a great need for further surveys of the reptile and amphibian fauna of the region.

Several large off-shore islands, including Buton and Kabaena Islands, occur in Sulawesi Tengarra. Until recently, no formal surveys for reptiles and amphibians had been conducted on these off-shore islands. In 2000, a herpetofaunal survey was undertaken in central Buton Island, south-east Sulawesi, by Operation Wallacea (Gillespie 2000). A total of 45 species of herpetofauna were detected in the limited area surveyed. This number included several new and undescribed species, and new records and range extensions for other poorly-known species. Further surveys are required to fully document the species of reptiles and amphibians on Buton Island.

Field surveys were conducted from June to August 2001. Sample sites were clustered in the Kakenawe and Lambusanga Reserves in central Buton Island. In order to sample as wide range of environments as possible, sample sites were chosen in a variety of different habitats, such as in gullies, on mid-slopes and ridges in forest, with varying levels of human disturbance, and at sites in highly disturbed habitats, such as regenerating cleared forest and plantations. Specific habitats, such as streams, swamps and caves, were also investigated. A variety of methods were employed to sample the herpetofauna, including pitfall trapping, transect censuses, nocturnal censuses and opportunistic searches.

Transects 100 m long were established at sample sites. One person walked slowly along each transect, pausing at regular intervals, and recording the numbers of each species observed. Diurnal censuses were conducted along each transect during mid-morning to mid-day. Nocturnal censuses were also conducted along these transects.

Pitfall trap-lines, comprising five 60 L buckets embedded in the ground, spaced 5 m apart, with a 1 mm gauge wire mesh drift fence 30 cm high and 20 m long, passing over the centre of each bucket. Each pitfall trap-line was checked every morning and operated for a minimum of four weeks.

Opportunistic nocturnal and diurnal searches were conducted for frogs and reptiles over a wider area. These searches involved walking slowly through various habitats, such as forests, along streams, through caves, mangroves, agricultural areas or swamps. During diurnal searches, logs, rocks or other ground debris were investigated for sheltering animals.

Voucher specimens of all taxa detected were collected to confirm field identification, to aid identification of unknown species or suspected new species, and to collect material for taxonomic groups requiring further systematic resolution. These specimens will be lodged with the National Museum in Bogor.

An additional 11 reptile and one frog species have been recorded from central Buton island so far this season. This brings the total check-list for the area to 45 reptile and 11 frog species. This list includes several new species to science including at least two snakes, three frog, one skink and two gecko species. The taxonomic identity of several other species collected requires resolution by examination of museum specimens held at Bogor. Some of these specimens may also represent new species. One hundred and fifty voucher specimens have been collected for lodgement at museums.

Most of the species located have not been recorded on Buton Island before, and many have not previously been listed as occurring in Sulawesi Tengarra. Consequently, these surveys have contributed significantly to baseline knowledge of the distribution of the Sulawesi herpetofauna. The survey this year increased the species checklist for the central Buton region by approximately 30%. It is therefore likely that further surveys in this region and other parts of Buton Island will result in the detection of more species.

Iskandar, D.T and Tjan, K. N. (1996). The amphibians and reptiles of Sulawesi, with notes on the distribution and chromosomal number of frogs. In: D.J. Kitchener and A. Suyanto (eds.), Proceedings of the First International Conference on Eastern Indonesian-Australian Vertebrate Fauna, Manado, Indonesia. Pp. 39-46.

Bosch, H. A. J. (1985). Snakes of Sulawesi: Checklist, key and additional biogeographical remarks. Zoologische Verhandelingen. Uitgegeven door Het Rijksmueum van Natuurlijke Historie Te Leiden. No. 217.

Gillespie, G. R. (2000). Herpetofauna Biodiversity Survey of the Labundo Bundo region of Buton Island, Sulawesi Tengarra, Indonesia, July-September, 2000. Unpublished report.