Siberut National Park is located on Siberut Island, Mentawai Islands Regency, West Sumatra. The National Park with an area of 190,500 hectares is determined through the Minister of Forestry Decree Number 407 / Kpts-II / 1993. Previously in 1981 the island had been designated a biosphere reserve through the UNESCO Man and Biosphere project.
On Siberut Island, there were 896 species of woody plants, 31 species of mammals, and 134 species of birds. There are four endemic species that are endangered. The four endemic species are Mentawai gibbons (bilou, Hylobates klossii), langur (joja, Presbytis potenziani), Mentawai monkeys (simakobu, Simias concolor), and beruk (bokoi, Macaca pagensis).