Tarsius wallacei

Listed as Data Deficient as Tarsius wallacei was recently described, and its population status cannot be reasonably estimated at this time. Additional surveys are needed.

This species occupies a discontinuous range in the province of Central Sulawesi. Northern and southern populations are isolated from each other by the Palu Bay, the city of Palu, and the southern parts of the Isthmus of Palu, an area now inhabited by the parapatric species T. dentatus. The current evidence indicates that the northern population occurs within the following geographic limits: an unknown line just west of the village of Tomini to the northeast (about 120º30'E), the coastlines of the Isthmus of Palu to the east and tho the west, and an unknown line between the village of Ampibabo and Marantale to the south (about 0º30'S). Along its northern border, this population borders the “Sejoli form” sensu Shekelle et al. (1997). At its southern limit, this population borders T. dentatus (Merker et al. 2010).

The southern population occurs southwest to west of Palu, it is definitely known from the type locality Uwemanje only and probably occurs in a very small area from Uwemanje to the west. Approximately 9 km to the south T. dentatus is found, and 24 km to the northwest, T. lariang (Merker et al. 2010).

The two populations are distinguished as T. wallacei Tinombo form (northern) and T. wallacei Uwemanje form (southern).

The isolated southern population of T. wallacei occurs in a very small area of probably no more than 5x10 km (Merker et al. 2010). Satellite images suggest an even much smaller area of occupancy in this region and thus, although population estimates are still lacking, a critical status of this stock is conceivable.

The species occurs in primary, secondary, and degraded forest habitats. So far, little is known on the ecology of T. wallacei. Given the morphological and ecological similarity of the species to other Sulawesi lowland tarsiers, this nocturnal primate is expected to feed on live animal prey with insects as the main component of its prey and to spend daylight hours in holes or crevices of strangling figs (Ficus spp.).

As other tarsier species, T. wallacei faces habitat loss and degradation effected by conversion of rainforest to cash crop plantations. In light of a very small range of the Uwemanje form, local policy-making in one or a few villages may be of high impact on this stock.

The range of the northern population of T. wallacei includes Gunung Sojol Nature Reserve.