Mountain Tarsier, Lesser Spectral Tarsier, Pygmy Tarsier, Sulawesi Mountain Tarsier
(Tarsius pumilus)
DD
Overview
The eyes of the pygmy tarsier can weigh more than brain and are unable to move in their sockets. Instead, tarsiers can rotate their heads nearly 360 degrees. The smallest of the known primates, tarsiers are spectacular jumpers and can leap 40 times their own body length. The family receives its name from the elongated tarsus bone in the ankle. Some researchers doubted the continued existence of Tarsius pumilus or in fact that it ever represented a separate species, as only two specimens were ever found and it had not been unambiguously identified in the wild since 1930. However, a recent investigation claims to have found a third specimen in Lore Lindu National Park, Central Sulawesi, Indonesia.
Urgent Conservation Actions
Status surveys to ascertain popluation size and distribution.
Distribution
Indonesia: Sulawesi
Media from ARKive
ARKive image - Lesser spectral tarsier in the hands of a researcher
Evolutionary Distinctiveness
Order: Primates
Family: Tarsiidae
The family Tarsiidae contains a single genus with five species. Tarsius pumilus has previously been considered a sub-species of the spectral tarsier, Tarsius spectrum. The fossil record for the family dates back to the Oligocene (34-24 mya). Fossils of tarsiers have been found in Asia, Europe, North America and Africa. Modern Tarsiidae species are restricted to a few islands in South East Asia. It is likely that tarsiers have occupied this region for over 40 million years. More species may remain to be discovered on other islands.

The taxonomy of tarsiers has been much debated. There is evidence that they are a living descendant of the diverse extinct family Omomyidae, for which the fossil record dates back to the Eocene (55-34 mya). Certain aspects of the body structure of Tarsiidae suggest a close relatedness to South American monkeys. The Philippine and Western species differ so significantly from the other three species (Diana tarsier, pygmy tarsier and spectral tarsier) that assigning them to new genus been discussed. At some stage ancestral tarsiers probably became diurnal and thus lost the Tapetum lucidum (a light reflecting layer in the eye) possessed by their nocturnal predecessors. When recent tarsiers became nocturnal they secondarily readapted to maximising the amount gathered in the dark by evolving very large eyes.
Description
Size: 
Head and body length: 9.5-10.5cm
Weight: Less than 100 g
The pygmy tarsier is the smallest primate species with a head-body measurement of just 9.5-10.5cm. The coat of this species is longer and curlier than in other tarsiers perhaps as adaptation to the cold damp environment in which it lives.The coat is very soft and varies in colouration from greyish brown to dark brown or buff. The fore-limbs are short but the hind limbs are greatly elongated and measure about twice length of the head and body combined. The tail is long and scaly with a few sparse hairs at the tip. The long fingers can form an effective cage for catching insects. The digits have flattened nails apart from the second and third toes which have claw like nails used for grooming. The rounded pads at the tips of the digits provide good grip for climbing. The head is rounded with a reduced muzzle. The large eyes are approximately 16mm in diameter, they can not move in their sockets and the tarsier compensates for this by being able to turn its head nearly 360 degrees. The ears are thin and membranous, they are constantly moving when the tarsier is active.
Ecology
These nocturnal primates spend the days sleeping in dense vegetation on vertical branches. They are active at night and twilight when they hunt for insects, snakes, birds and small vertebrates which they seize with both hands. Little is known about reproduction in Tarsius pumilus. In the spectral tarsier, Tarsius spectrum, and possibly Tarsius pumilus there are two breeding seasons a year at the beginning and end of the rainy season, approximately 6 moths apart. Births occur in May and also in from November and December. In other tarsier species sexual maturity is reached at about 1 year. Courtship involves soft vocalisations and much chasing around. Copulation takes place on a tree branch. All species have long gestation periods and give birth to a single young which is born furred with its eyes open. Relative to the body size of the mother tarsiers give birth to the largest babies of any mammal. The young clings to the mother’s abdomen fur and is sometimes carried in her mouth. The spectral tarsier lives in groups of 2 or 3. A promiscuous mating system has been suggested. Olfaction is important in communication and males mark territories with urine and secretions from a gland on chest. Vocalisations in the form of social calls are heard mostly at sun rise. The average home range for tarsiers is approximately 2ha. The extent to which tarsiers use visual signals, such as postures and displays, is not known.
Habitat
Endemic to central Sulawesi, Indonesia. It is present in the altitudinal range of 1,800 to 2,200m in montane rain forest where it rains frequently and when it is not raining the mountains are shrouded with thick, grey mist.
Distribution
The average home range for tarsiers is approximately 2ha.
Population Estimate
Unknown.
Population Trend
Unknown.
Status
Listed as Data Deficient in the 2004 IUCN Red List of Threatened Species. Recent field surveys had failed to rediscover this species at its reported type locality (Rano Rano in Central Sulawesi). Some researchers doubted its continued existence or even validity as a species. It had not been unambiguously identified in the wild since 1930. However, a recent investigation claims to have found a third specimen in Lore Lindu National Park, Central Sulawesi, Indonesia.
Threats
The species is apparently abundant in some localities on Sulawesi but in general is vulnerable. People have attempted to keep tarsiers as pets but they react badly to the trauma of capture and in the absence of live food they usually die within a couple of days. The greatest threat to this species is that of escalating habitat loss and degradation. Fortunately most of this region is still intact and much of the original habitat still remains. Logging activity has been discouraged by the steep slopes and relative low value of timber. However, where logging has occurred severe environmental damage has take place, extensive erosion has resulted and rivers and steams have been clogged with run off. Hunting and human induced fires are also threats and along with logging will probably continue in the future. Other threats include transmigration and local clearance.
Conservation Underway
In Indonesia tarsiers are protected by law. Tarsiers are listed in Appendix II of CITES; international trade is monitored through a licensing system to ensure that trade can be sustained without detriment to wild populations. Trade in wild, captive bred and artificially propagated specimens is allowed, subject to permit. Twenty-nine protected areas exist in this locality covering approximately 23 percent of the eco-region. The average size of a protected area is 602 km2, and there are five protected areas that exceed 1,000 km2.
Conservation Proposed
There are currently no conservation measures proposed for this species.
References
Beard K.C. and Wang B. 1991. Phylogentic and biogeographical significance of the tarsiifrom primate Asiomomys changbalcus from the Eocene of Jilin Province, Peoples Republic of China. American Journal of Phylogenetic Anthropology. 85: 159-166

Eudey, A. & Members of the Primate Specialist Group 2000. Tarsius pumilus. In: IUCN (2004).2006 IUCN Red List of Threatened Species. Downloaded on 08 March 2006.

Macdonald, D. (ed.) 2001. The New Encyclopedia of Mammals. Oxford University Press, Oxford, New York.

Maryanto, Ibna and Yani, Mohamad (2004) The third record of pygmy tarsier (Tarsius pumilus) from Lore Lindu National Park, Central Sulawesi, Indonesia. Tropical Biodiversity 8 (2): 79-85: 2004

Musser, G., Dagosto M. 1987. The identity of Tarsius pumilus, a pygmy species endemic to the montane mossy forests of central Sulawesi. American Museum Novitates No. 2867 pp. 1-53. New York: American Museum of Natural History.

Nowak, R.M. (ed.) 1999. Walkers Mammals of the World. Sixth edition. The Johns Hopkins University Press, Baltimore and London.

Simons E.L. and Brown T.M. 1985. Afrotarsius chatrathi, first tarsifrom primate (Tarsiidae) from Africa? Nature 313: 475- 477

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