Siau Island Tarsier

Siau Island tarsier (Tarsius tumpara) is a species of tarsier from the tiny volcanic island of Siau. It was described by Shekelle M, Groves C, Merker S. Supriatna J. (2008) Tarsius tumpara: a new Tarsius Siautarsier species from Siau Island, North Sulawesi. Primate Conservation (23):55–64[1].

Its existence as a distinct taxon was predicted by the hybrid biogeographic hypothesis for Sulawesi, described by Shekelle M, Leksono SM. (2004). Rencana konservasi di Pulau Sulawesi: dengan menggunakan Tarsius sebagai flagship spesies Biota IX(1):1-10. The rationale was that a geographic discontinuity existed between the northern tip of Sulawesi, and the population of tarsiers on Sangihe Island (Tarsius sangirensis), approximately 200 kilometres (120 mi) to the north. In between, lay very deep oceans and three island clusters, Biaro, Tagulandang/Ruang, and Siau. Like Sangihe Island, itself, each of these three island clusters are a part of the Sangihe Island volcanic arc. Volcanic arcs, like the Galapagos and Hawaiian Island chains, feature islands that erupt from the ocean floor. In such circumstances, islands form independently, are colonized independently, and remain geographically isolated. These characteristics lead to high levels of endemism. The presence of tarsiers on the most distant island group in the Sangihe volcanic arc (i.e. Sangihe island), led to curiosity about the presence of tarsiers on the other islands in the chain. Each of the three island clusters mentioned above were surveyed for the presence of tarsiers in 2004 and 2005, but tarsiers were only observed on Siau.

It was furthermore elaborated upon that the original description of T. sangirensis included mention of a specimen from Siau in the Dresden museum. Thus, Brandon-Jones D, Eudey AA, Geissmann T, Groves C, Melnick DJ, Morales JC, Shekelle M, Stewart CB. Asian primate classification. (2004). International Journal of Primatology 25(1):97-164, argued for further investigations of the Siau tarsier to see if it was taxonomically separable from T. sangirensis.

The Sangihe Islands are infamous for their critically endangered avifauna, and concerns about the conservation status of T. tumpara grew before its formal description, Shekelle M, Meier M, Indrawan M, Maryanto I, Salim A, Supriatna J, Andayani N, Wirdateti (2007) “When ‘Not Extinct’ is Not Good News: Conservation in the Sangihe Islands”. Conservation Biology 21(1):4-6.

Tarsius tumpara was selected to the list of Top 25 Most Endangered Primates by the IUCN Species Survival Commission, Primate Specialist Group, for the period 2006-2008, Shekelle, M. and Salim, A. (2007). Newly described, status of Siau Island Tarsier has not yet been assessed in IUCN redlist. Siau Island Tarsier, Tarsius sp. Shekelle et al., In: Primates in Peril: The World’s 25 Most Endangered Primates 2006-2008, R. A. Mittermeier et al. (compilers), pp.20–21, 43-44. IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS), and Conservation International (CI), Arlington, VA, and again for 2008-2010, Shekelle and Salim (in prep).[2]

Shekelle M, Salim A. (In Press). An acute conservation threat to two tarsier species in the Sangihe Island chain [North Sulawesi, Indonesia] Oryx, recommend that T. tumpara be listed as Critically Endagangered (CR A1acd).