Distribution, and abundances of Peleng Tarsier (Tarsius pelengensis), in Banggai Island group, Indonesia

The Peleng tarsier (Tarsius pelengensis) is a practically unknown prosimian, with a very narrow range limited to Banggai island-group, Central Sulawesi, Indonesia. It was classified as "Endangered" by IUCN in 2017. Detailed demographic and distribution information about T. pelengensis in the wild is not available even though they are crucial to setting up conservation priorities and strategies. The aim of this study was to analyze distribution, and population of T. pelengensis across the island group. Surveys were conducted over approximately five months in 2017 and 2018 across Peleng and the neighboring islands of Banggai, Labobo, and Bangkurung. It is now established that tarsiers occur on two of the major islands, namely Peleng and Banggai Island proper. Average density in Peleng and Banggai islands were estimated to be 247 individuals/km2, and this roughly fall within the broad ranges of tarsier densities in Sulawesi and offshore islands. In stark contrast to the only previously available supposition of distribution and conservation status (IUCN 2017), Tarsiers were found in nearly all elevations (0-937 m above sea level) and all habitats in Peleng island. There is also an entire newly discovered population in Banggai Island proper, which similarly distributed in varied habitats. Therefore, the conservation status of Peleng tarsier needs to be re-evaluated.