Siau Island Tarsier
Tarsier sp. Shekelle et al., in prep.


Dikuitip dari:  http://www.primate-sg.org/siau07.htm


 The Siau Island tarsier is a new, undescribed species that is Critically Endangered (A1 acd) and faces an imminent threat of extinction. Shekelle and Salim (in press) used GIS data and field surveys to list specific threats. They include: a very small geographic range, of 125 km², and an even smaller area of occupancy, perhaps as little as 19.4 km²; a high density of humans (311 people per km²) that habitually hunt and eat tarsiers for snack food; and an extent of occurrence that is entirely volcanic in its geological composition, with Mount Karengetang, a massive and highly active volcano, dominating more than 50% of the geographic range of this species. Furthermore, there are no protected areas within its range (Riley 2002; Shekelle and Salim in press; Shekelle et al. 2007), and all captive breeding programs for tarsiers, including several by leading zoos and primate centers, have been dismal failures, leaving no ex situ conservation options for any tarsier species anywhere (Fitch-Snyder 2003).

The most reasonable interpretation of the scant data is that population size is very small, in the low thousands at best, and declining (Shekelle and Salim in press). Despite the fact that Sangihe Island is renowned for its Critically Endangered avifauna (Whitten et al. 1987; Whitten 2006), Shekelle and Salim (in press) found that the conservation threat for the tarsier on Siau Island was greater, for every variable measured, than that faced by T. sangirensis on Sangihe Island, which nevertheless is Endangered (B12 ab). Thus, in spite of the fact that this species has yet to be described and is almost unknown, sufficient available evidence indicates that it teeters on the brink of extinction on an island where the entire endemic fauna and flora are at risk (Shekelle et al. 2007).

In Meyer’s (1897) description of T. sangirensis, from Sangihe Island, he included a single skull from Siau Island (in the Dresden Museum, B321, from “Siao”). Sangihe and Siau Islands are part of a volcanic arc and are separated by approximately 60 km of deep ocean, greater than 1000 m in depth. There is no feasible means for recurrent gene flow between these islands today, nor is there any historical indication of a land connection between these islands. Accordingly, Brandon-Jones et al. (2004) suggested that the Siau Island population is taxonomically distinct. Shekelle visited the island in March 2005 and found acoustic and morphologic evidence that supported taxonomic separation of the Siau Island population. Aside from the skull in Dresden, there is no evidence in the literature of research on this species.

Shekelle’s surveys found evidence of tarsiers in only two places, on the shores of a small fresh water pond at the extreme southern end of the island, and on a steep cliff face along the east coast road where it runs next to the ocean. Numerous other sites that looked promising, based upon experience with T. sangirensis, turned up no evidence of tarsiers. Interviews with several locals indicated that tarsiers had formerly been common at these sites as recently as 10 years ago, but were now rare or non-existent. They also added that tarsiers were a popular snack food called “tola-tola”, and that it had formerly been common to eat 5 to 10 at a single sitting after hunting them with air rifles. It is unsurprising that tarsiers are no longer found in these areas.


Myron Shekelle & Agus Salim




Brandon-Jones, D., A. A. Eudey, T. Geissmann, C. P. Groves, D. J. Melnick. J. C, Morales, M. Shekelle and C.-B. Stewart. 2004. Asian primate classification. Int. J. Primatol. 25(1): 97–164.

Fitch-Snyder, H. 2003. History of captive tarsier conservation. In: Tarsiers: Past, Present, and Future, P. C. Wright, E. L. Simons and S. Gursky (eds.), pp.277–295. Rutgers University Press, New Brunswick, NJ.

Meyer, A. B. 1897. Säugethiere vom Celebes- und Philippinen-Archipel, I. Abhandlungen und Berichte der Kaiserlich Zoologische und Anthropologische-Ethnologische Museum zu Dresden 6(I–VIII): 1–36.

Riley, J. 2002. Mammals on the Sangihe and Taluad Islands, Indonesia, and the impact of hunting and habitat loss. Oryx 36(3): 288–296.

Shekelle, M. and S. M. Leksono. 2004. Rencana Konservasi di Pulau Sulawesi: Dengan Menggunakan Tarsius Sebagai ‘Flagship Taxon’. Biota IX(1): 1–10.

Shekelle, M., M. Meier, M. Indrawan, I. Maryanto, A. Salim, J. Supriatna, N. Andayani and Wirdateti. 2007. When ‘not extinct’ is not good news: Conservation in the Sangihe Islands. Conserv. Biol. 21(1): 4–6.

Shekelle M. and A. Salim. In press. An acute conservation threat to two tarsier species in the Sangihe Island Chain (North Sulawesi, Indonesia). Oryx.

Shekelle, M. et al. In preparation. Tarsius xxxxxx: a new tarsier species from Siau Island, North Sulawesi [species name withheld prior to publication].

Whitten, T. 2006. Cerulean Paradise-Flycatcher not extinct: Subject of the first cover lives. Conserv. Biol. 20(3): 918–920.

Whitten, T., S. D. Nash and K. D. Bishop. 1987. One or more extinctions from Sulawesi? Conserv. Biol. 1: 42–48.


Suggested citation:

Shekelle, M. and Salim, A. 2007. Siau Island Tarsier, Tarsius sp. In: Primates in Peril: The World’s 25 Most Endangered Primates 2006–2008, R. A. Mittermeier et al. (compilers), p.12. Unpublished report, IUCN/SSC Primate Specialist Group (PSG), International Primatological Society (IPS), and Conservation International (CI), Arlington, VA.