Habitat use by stream-breeding frogs in south-east Sulawesi, with some preliminary observations on community organization

The habitat associations of stream-breeding frogs were examined along a series of stream transects on Buton Island in south-east Sulawesi, Indonesia. Of the eight frog species located along streams, four were observed breeding in stream habitats. We examined spatial habitat partitioning among these species. Three of the four species were found to be associated with a non-random selection of the available perch sites. Strong partitioning between species in habitat associations was found; partitioning of the available habitat space was primarily associated with differences in proximity to stream features, and in the height of perch sites. General observations indicated that oviposition sites of most species were associated with the microhabitats in which the adult frogs were found. All four stream-breeding species appear to have synchronous breeding phenologies and the spatial relationships of these species within the habitat space appear to reflect partitioning of calling sites and oviposition sites. The stream-breeding frog community in this region of Sulawesi has much lower species richness and less specialized habitat use compared with other tropical stream-breeding frog communities in the region. (Bahasa Indonesia): Asosiasi habitat antara katak dengan lingkungan diteliti pada jenis-jenis amfibi riparia sepanjang transek sungai di pulau Buton, Sulawesi Tenggara, Indonesia. Dari delapan jenis katak yang ditemukan sepanjang sungai, empat jenis di antaranya berkembang biak pada waktu penelitian ini berlangsung. Telah diamati pula pola pemisahan habitat antar jenis-jenis yang diamati. Tiga dari empat jenis ditemukan secara acak pada semua macam tempat hinggap. Pemisahan habitat antar jenis mempunyai korekasi yang sangat kuat terhadap jarak dari sungai dan ketinggian tempat hinggap. Walaupun demikian tempat peneluran sangat erat berasosiasi dengan iklim mikro masing-masing jenis. Keempat jenis yang diamati, masing-masing mempunyai musim peneluran yang relatif sinkron dan mencerminkan pemisahan habitat sesuai dengan tempat melakukan panggilan kawin dan tempat bertelur. Pola yang diamati dibandingkan pula dengan data yang terdapat dari Borneo. Disimpulkan bahwa katak yang berkembang biak di sungai-sungai di Buton, Sulawesi mempunyai keanekaragaman jenis yang rendah dan juga relatif tidak terspesialisasi dalam penggunaan habitat.