Studi Populasi Siamang (Simphalangus syndactylus) DI Hutan Lindung Register 25 Pematang Tanggang Kabupaten Tanggamus

Siamang (Simphalangus syndactylus Raffles, 1821) was the primates that protected by government regulation of Republic Indonesia number 7 in 1999. The existence of the siamang was important role in forest as pollinator and seed dispersers. Conversion land has increased into plantations and agriculture so that siamang population became descreased. Protected forest on Register 25 Pematang Tanggang Tanggamus Regency was bordered by community forest, thus vulnerable to land use that siamang population became descreased. The aimed of the research was to find the size of the group, the composition of age, the sexual ratio and the habitat of siamang in protected forest Register 25 Pematang Tanggang. The method used an area concentrated in 3 areal observation. Observations were 30 days effective. The results of this research showed that the Group of siamang found about 3 groups/7 individuals. The distribution of age classes in the individual adult phase of siamang about 6 individuals, adolescent phase about 1 individual and baby phase not found in this group. The sex ratio value in the adult age class phase was 1:1 and at adolescent age class phase was 1:0. According to siamang society does not interfere with human activities so that  not harm for them and their habitat was quite adequate for a population of siamang. Keywords: protected forest, population, siamang