Siau Island tarsier

Tarsiers are found in Southeast Asia, though the T. tumpara is endemic to Siau Island, Indonesia.[5] This species was located geographically using GIS and Geographic Profiling and they have found that they live in a small range of 125 km${\displaystyle ^{2}}$, with an even smaller occupancy range of approximately 19.4 km${\displaystyle ^{2}}$.[6][7] The tumpara tarsier species has a population of approximately 1,358–12,470 and is declining due to the many threats they face.[4]

Sulawesi map

The Ficus tree, a tarsier habitat

Its existence as a distinct taxon was predicted by the hybrid biogeographic hypothesis for Sulawesi.[8] The rationale was that a geographic discontinuity existed between the northern tip of Sulawesi, and the population of tarsiers on Sangihe Island (the Sangihe tarsier Tarsius sangirensis), approximately 200 kilometres (120 mi) to the north.[8] 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.

T. tumpara on a tree

It was furthermore elaborated upon that the original description of T. sangirensis included mention of a specimen from Siau in the Dresden Museum. Thus it was argued for further investigations of the Siau tarsier to see if it was taxonomically separable from T. sangirensis.[9]

The Sangihe Islands are known for their critically endangered avifauna, and concerns about the conservation status of the Siau Island tarsier grew before its formal description.[10] The Siau Island tarsier was selected for the list of "The World's 25 Most Endangered Primates" by the IUCN Species Survival Commission, Primate Specialist Group.[11] The Sangihe Islands are known for their critically endangered avifauna, and concerns about the conservation status of the Siau Island tarsier grew before its formal description.[12] Some of the reasons as to why this species of tarsier is critically endangered is because they are hunted for their meat, to be used as traditional medicine and to be sold as domestic pets in the pet trade.[13] Its habit is at risk since it is not recorded as a protected area, and therefore is subjective to drastic habitat loss if no conservation practices are put in place.[14] The progressive disappearance of its habitat, with the large population of the Siau people [311 people/km2], restrains the primate communities within a small area. [7] Other threats such as the volcanic activities of the island, though most of these are interconnected and all play an important role in the endangerment of the tumpara tarsier.[13] This species is rapidly declining, having declined by more than 25% in the last 25 years.[3]

• Shekelle, M.; Salim, A. (2009). "An acute conservation threat to two tarsier species in the Sangihe Island chain, North Sulawesi, Indonesia". Oryx. 43 (3): 419–426. doi:10.1017/S0030605309000337.

• siau-island-tarsier/tarsius-tumpara Siau Island tarsier (Tarsius tumpara) media from ARKive