Pygmy Tarsier (Tarsius pumilus)


MORPHOLOGY:
This nocturnal species has large eyes and large ears that are mobile. The pygmy tarsier has a special adaptation in its neck vertebrae to help it turn its head 180 degrees. It needs to do this because its eyes can not move. The dental formula of this species is 2:1:3:3 on the upper jaw and 1:1:3:3 on the lower jaw (Nowak, 1999). This species has relatively small upper canines (Nowak, 1999). The lower incisors of this species are higher than the canines (Musser and Dagosto, 1987). This species lacks a tapetum lucidum found in most nocturnal animals. The pygmy tarsier has two grooming claws on each foot instead of just one. The nails are more laterally compressed as to resemble claws (Musser and Dagosto, 1987). The tail of this species is naked except for a tuft of hair at the end. This species receives its name from the elongated tarsus bone. Females have two pairs of mammae, one inguinal and one pectoral. The pygmy tarsier has a pelage color which is reddish brown on the dorsal side, and the pelage is relatively longer as compared to Tarsius spectrum (Musser and Dagosto, 1987). The longer pelage may be an adaptation for living in the colder and wetter habitats of the montane forests (Musser and Dagosto, 1987). Behind each ear there is a buffy colored spot (Musser and Dagosto, 1987). The head and body length of this species is only 75 percent of other members of the genus Tarsius (Musser and Dagosto, 1987). The average mass for the pygmy tarsier is about 50.07 grams and the head and body length is about 80 millimeters (Grow and Gursky-Doyen, 2010). This species has a smaller body size as compared to other lowland tarsiers of Sulawesi and relatively long limb proportions that would result in heat loss instead of heat conservation as would expected from a species that lives in high altitudes (Grow and Gursky-Doyen, 2010). This violates both Bergmann's rule and Allen's rule (Grow and Gursky-Doyen, 2010).

RANGE:
The pygmy tarsier is found on the island of Sulawesi (Musser and Dagosto, 1987). This species lives in the mossy, upper montane rainforests of central Sulawesi (Musser and Dagosto, 1987).

ECOLOGY:
This species is a carnivorous species. Group size average about 4 individuals and are composed of about 2 adult males, one adult female, and young (Grow and Gursky- Doyen, 2010). Individuals in a group sleep together in a shared sleeping site, which is most often a nest in a large tree in the canopy level and groups tend to use one dedicated site (Grow and Gursky-Doyen, 2010).

LOCOMOTION:
This species is a vertical clinger and leaper.

SOCIAL BEHAVIOR:

VOCAL COMMUNICATION:
alarm call: Pygmy tarsiers will emit this in response to avian predators, but it was found that they will not emit the call when avian predators are near the sleeping site (Grow and Gursky-Doyen, 2010).

OLFACTORY COMMUNICATION:
scent-marking: This species was found to scent-mark less frequently than other tarsier species and may be due to the high montane moss forests where high rainfall and moss may make the use of scent-marrking less favorable (Grow and Gursky- Doyen, 2010).

VISUAL COMMUNICATION:


TACTILE COMMUNICATION:

REPRODUCTION:

REFERENCES:
Grow, N. and Gursky-Doyen, S. 2010. Preliminary data on the behavior, ecology, and morphology of pygmy tarsiers (Tarsius pumilus). International Journal of Primatology. Vol. 31(6), 1174-1191.

Musser, G.G. and Dagosto, M. 1987. The identity of , a pygmy species endemic to the montane mossy forests of central Sulawesi. American Museum Novitates. Vol. 2867, 1-53.

Nowak, R.M. 1999. Walker's Primates of the World. The Johns Hopkins University Press: Baltimore.

Last Updated: January 9, 2011.
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