Studi Habitat dan Perilaku Orang Utan (Pongo pygmaeus abelii) di Bohorok Taman Nasional Gunung Leuser.

Abstract

Orang-utans are big primates living arboreally and solitarily. Their solitary characteristics, wich was found to be quite different from those of other primate species, have been one of the difficulty factors for discovering them in their dwelling places in forests. This in turn, have resulted in a limited number of orang-utans having systemtically been traced during the course of data. collection. The study was aimedd to explore the habitat, daily activities and population of orang-utans related to habitat condition of Bohorok Nastional Park located in Gunung Leuser, and was carried out in forest areas of Sungai Landak and Sungai Musam, from July 1991 until January 1992. Survey methods employed were both the descriptive and qualitative methods. Observations on habitat conditions have included forest structure, vegetation type and composition, preference of food types and home range. Observations on feeding behavior, movements, restings and defensive behaviour to human disturbances and predators within their home range have also been carried out. Vegetation analysis have been carried out by using multiple plot method, and 144 sample plots have been obtained from five longitudinal stripes in forest areas of Sungai Landak and Sungai Musam. ehowed that the dominant species was materialis) with INP of Vegetation analysis 'damar laut' (Shorea 20.06%, 'kayu minyak' (Dipterocarpus sp.) with INP of 19.5%, 'samak jambu (Ixonanthus icesandra) with INP of 15.60%, and 'kayu merah' (Eugenia sp.) with INP of 13.1%. Tree density was fourd to be relatively low, i.e.. only 216 trees/ha, with species variability index (Shannon Wiener Index) of 3.78 and uniformity index of 0.83. Species variability index was considered relatively high and consisted of various age levels of natural forests. Among the various species related to tree densities, the densities of those which served as principal food sources of orang-utans, have been found to be relatively low. Tree density of Ficus sp. for example, was only 0.90 trees/ha, rambung-rambung' (Vernonea arborea) 1.67 trees/ha, rengas' (Gluata rengas) only 0.69 trees/ha, 'baju barus' (Manglietia glauca) 0.83 trees/ha, 'banitan' (Polyanthia glauca) 0.83 trees/ha.