Siberut National Park comprises 1,905 km2 (47%) of the island of Siberut in the Mentawai Islands of West Sumatra, Indonesia. The whole island including the national park is part of the World Network of Biosphere Reserves. The notable aspects of the park are its endemic fauna, flora, and indigenous inhabitants, the Mentawai, who still live according to hunter-gather traditions. The Mentawai Islands are thought to have been isolated from mainland of Sumatra for over 500,000 years, thereby producing unique ecosystems.