Tarsius dentatus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Mammalia Primates Tarsiidae

Scientific Name: Tarsius dentatus
Species Authority: Miller & Hollister, 1921
Common Name(s):
English Dian's Tarsier, Diana Tarsier
Tarsius dianae Niemitz, Nietsch, Warter & Rumpler, 1991
Taxonomic Notes: The form known as T. dianae (Niemitz et al. 1991) is almost certainly a subjective junior synonym of T. dentatus (M. Shekelle pers. comm. 2007).

Assessment Information [top]

Red List Category & Criteria: Vulnerable A4c ver 3.1
Year Published: 2008
Date Assessed: 2008-06-30
Assessor(s): Shekelle, M., Salim, A. & Merker, S.
Reviewer(s): Mittermeier, R.A. & Rylands, A.B. (Primate Red List Authority)
This species is considered Vulnerable based on habitat loss alone, as at least 30% of the habitat has been converted in the past 20 years (approximately 3 generations). From 1990 to 2000, from 15 to 26% of the forest habitat on the island was converted to agriculture (A. Salim pers. comm.), and since that time at least an additional 10% has been lost.
Previously published Red List assessments:
2000 Lower Risk/conservation dependent (LR/cd)
1996 Data Deficient (DD)
1994 Indeterminate (I)

Geographic Range [top]

Range Description: The species occurs in the eastern portion of the central core of Sulawesi, Indonesia. The northern boundary is the Isthmus of Palu between Marantale (Shekelleet al. 1997), Ampibabo (Stefan Merker unpubl. data), and Tomini Bay. The species is distributed east to the tip of the eastern peninsula (J. Burton unpubl. data). The western boundary appears to extend at least to the Palu River and south as far as Gimpu (Merker and Groves 2006). The southern boundary from Lore Lindu National Park to the eastern coast of Sulawesi is unknown. In this estimate, the southern border is inferred to be the edge of the main, east-central microplate. This puts the estimated faunal boundary somewhat to the north of the boundary between Macaca tonkeana and M. ochreata.
Countries occurrence:
Indonesia (Sulawesi)
Upper elevation limit (metres): 1100
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Merker (2003) estimated population densities in a variety of pristine and human disturbed habitats. The values he calculated were 270/km2 in pristine habitat, 190/km2 for slightly disturbed habitat, 130/km2 for moderately disturbed habitat, and 45/km2 in heavily disturbed habitat (Merker 2003).
Current Population Trend: Decreasing
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: This species has been studied in the field (Tremble et al. 1993; Merker 2006; Merker et al. 2005; Merker 2003; Merker and Mühlenberg 2000; Gursky 1998). It occurs in primary, secondary and mangrove forests, forest gardens, and a variety of other habitats of varying degrees of human disturbance that provide adequate shrubby cover. Like all tarsiers it shows extreme adaptations for vertical clinging and leaping (VCL) in the understory of suitable tropical habitats, often 0 m or less from the ground. Nocturnal social primates, they likely live in small, monogamous or polygamous groupings of 2-7 individuals (Merker 2003). Home range sizes have been recorded as 1.0–1.8 ha depending on habitat type. The diet is 100% live animal prey, mostly insects with some small vertebrates.
Systems: Terrestrial

Threats [top]

Major Threat(s): The primary threat to this species is loss of habitat loss due to illegal logging. Other threats include agricultural pesticides and predation by domestic animals (dogs and cats). In addition, some animals are entering the pet trade. There has been extensive loss of lowland forest habitat; however, the species has some tolerance to forest conversion. A crucial unknown variable in determining how critical the threats to this species are is its elevational distribution. GIS data indicate that large areas of quality forested habitat remain at higher elevations, but the vertical range of this species is believed to stop somewhere between 1,100-1,500 m, thus rendering a large portion of the best remaining habitat outside the range.

Conservation Actions [top]

Conservation Actions: Tarsiers are protected by national law and international treaties, including CITES Appendix II. Many portions of the range of this taxon are protected and indeed it occurs in at least two national parks (Lore Lindu and Morowali); however, there needs to be improved management of the currently protected areas to ensure the ongoing survival of the species. Public education to overcome the misconception that tarsiers are crop pests would be a step forward in improving conservation measures for the species. In fact the species might actually be beneficial to crops, as they eat, and may even have a dietary preference for, some of the real crop pests such as large grasshoppers.

Citation: Shekelle, M., Salim, A. & Merker, S. 2008. Tarsius dentatus. The IUCN Red List of Threatened Species 2008: e.T21489A9286921. . Downloaded on 04 May 2016.
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