Mitered Leaf-monkey (Presbytis melalophos)

MORPHOLOGY: The incisors are narrow and the molars have sharp, high crests (Oates and Davies, 1994). This species has a dental formula of 2:1:2:3 on both the upper and lower jaws (Ankel-Simons, 2000). The jaw is deep and the face is short and broad (Oates and Davies, 1994). The pollex (thumb) is reduced in this species (Davies, 1991). The orbits are widely spaced and the hindlimbs are longer as compared to the forelimbs (Oates and Davies, 1994). The average body mass for an adult male mitered leaf-monkey is around 5.9 kilograms, and for the female it is around 5.8 kilograms (Rowe, 1996). This species has a sacculated stomach to assist in the breakdown of cellulose. Infants have a white pelage color with a dark stripe down the back and across the shoulders (Rowe, 1996). This species has four subspecies each having their own pelage coloration:

• Presbytis melalophos melalophos: The ventral side is white to pale reddish and the dorsal side is red to yellow or buff and tinged with black hairs (Aimi and Bakar, 1992). The outer surface of the limbs is like the dorsal side but lighter (Aimi and Bakar, 1992). The tail is dark dorsally and light ventrally (Aimi and Bakar, 1992). This subspecies has a blackish colored crest that is reddish to buff frontally on the head (Aimi and Bakar, 1992). The hands and feet are either black or the same color as the limbs (Aimi and Bakar, 1992).
• Presbytis melalophos mitrata: The ventral side is white and the dorsal side and the outer surface of the limbs is ashy gray in coloration (Aimi and Bakar, 1992). The tail is grayish on the dorsal side and whitish on the ventral side (Aimi and Bakar, 1992). There is a black D-pattern on the crest that encloses the white hairs of the forecrown (Aimi and Bakar, 1992).
• Presbytis melalophos bicolor: The forehead is shaded by a black fringe and the eyes are surrounded by bluish gray or gray skin (Aimi and Bakar, 1992). The muzzle of this subspecies is black and the chin is gray or flesh-colored (Aimi and Bakar, 1992). On the crown there is a black sagittal stripe (Aimi and Bakar, 1992). The dorsal side and the outer surface of the forelimbs are dark chocolate in coloration (Aimi and Bakar, 1992). The hands, feet, and the outer surface of the hindlimbs are black (Aimi and Bakar, 1992). The throat, inner surface of the limbs, and the ventral side are white (Aimi and Bakar, 1992). The tail is black dorsally and white ventrally (Aimi and Bakar, 1992).
• Presbytis melalophos sumatrana: The dorsal side and the outer surface of the limbs are dark brownish or brown in coloration and the ventral side and the inner surface of the limbs to the wrist and ankle are creamy white (Aimi and Bakar, 1992).The dorsal surface of the tail is brownish black and the ventral is creamy white (Aimi and Bakar, 1992). The hands and feet of this subspecies are black (Aimi and Bakar, 1992). The hair on the sides of the median crest is the same color as the back, which is colored dark brownish gray (Aimi and Bakar, 1992). The throat is creamy white, the face bluish, the muzzle flesh-colored, and the lips black in this subspecies (Aimi and Bakar, 1992).

RANGE:
The mitered leaf-monkey is found in the country of Indonesia, on the island of Sumatra. This species lives in primary lowland rainforests, hill forests, inland secondary forests, and submontane forests (Crockett and Wilson, 1980; Wilson and Wilson, 1976; Aimi and Bakar, 1996).

This species has four subspecies, each having a different range:

• Presbytis melalophos melalophos: This subspecies is found in the southwestern part of Sumatra (Aimi and Bakar, 1992). The range is from the upper Rokan river to southeast of the upper Hari river (Aimi and Bakar, 1996).
• Presbytis melalophos mitrata: This subspecies is found south of the Hari river in Sumatra (Aimi and Bakar, 1992).
• Presbytis melalophos bicolor: This subspecies is found between the Inderagiri river in the north and the Hari river in the south (Aimi and Bakar, 1992).
• Presbytis melalophos sumatrana: This subspecies is found between the Wampu river and Simpangkiri river in the north and the Barumun river and upper Rokan river in the south of Sumatra (Aimi and Bakar, 1992, 1996).

ECOLOGY:
The mitered leaf-monkey is primarily a folivorous species, but will also consume fruits, flowers, and seeds. The fruits this species consumes are of the dry, unripe type (Rowe, 1996). Group sizes for this species have a mean number of 5.5 individuals (Beauchamp and Cabana, 1990). Wilson and Wilson (1976) found the mean group size to be 8 individuals for the mitered leaf-monkey. This is a diurnal and an arboreal species.

LOCOMOTION:
The mitered leaf-monkey moves through the forest quadrupedally (Fleagle, 1988). This species also moves through the forest primarily by leaping and also to a lesser extent by forelimb suspension (brachiation) (Fleagle, 1988).

SOCIAL BEHAVIOR:
The mitered leaf-monkey has a unimale social system and a polygynous mating system. This species can also have a multimale-multifemale social system (Rowe, 1996). All-male groups occur in this species (Newton and Dunbar, 1994). Females perform most of the grooming bouts in the group. Males disperse from the natal group before adolescence. The mitered leaf-monkey is a territorial species (Beauchamp and Cabana, 1990). Intergroup aggression in this species is a result of mate defense and not due to resource defense (van Schaik et al., 1992).

VOCAL COMMUNICATION:
loud call: In the mitered leaf-monkey, this call is a single phrase vocalization (Aimi and Bakar, 1992). This call sounds like chi-chi-CHI-chi-chi (Wilson and Wilson, 1976). This call is heard most frequently as the group leaves the sleeping site (Wilson and Wilson, 1976).

OLFACTORY COMMUNICATION:

VISUAL COMMUNICATION:

TACTILE COMMUNICATION:
social grooming: This is when one individual grooms another and is used to reinforce the bonds between individuals.

REPRODUCTION:
The mitered leaf-monkey gives birth to a single offspring.

REFERENCES:
Aimi, M. and Bakar, A. 1992. Taxonomy and distribution of Presbytis melalophos group in Sumatera, Indonesia. Primates. Vol. 33(2), 191-206.

Aimi, M. and Bakar, A. 1996. Distribution and deployment of Presbytis melalophos group in Sumatera, Indonesia. Primates. Vol. 37(4), 399-409.

Ankel-Simons, F. 2000. Primate Anatomy: An Introduction. Academic Press: San Diego.

Beauchamp, G. and Cabana, G. 1990. Group size variability in primates. Primates. Vol. 31(2), 171-182.

Crockett, C. and Wilson, W.L. 1980. Survey of Sumatran primates: Diversity and abundance in a shrinking paradise. Tigerpaper. Vol. 8(2), 1-5.

Davies, A. G. 1991. Seed-eating by red leaf monkeys (Presbytis rubicunda) in dipterocarp forest of northern Borneo. International Journal of Primatology. Vol. 12(2), 119-144.

Fleagle, J. G. 1988. Primate Adaptation and Evolution. Academic Press.

Newton, P.N. and Dunbar, R.I.M. 1994. Colobine monkey society. in Colobine Monkeys: Their Ecology, Behaviour and Evolution. eds. A.G. Davies and J.F. Oates. Cambridge University Press: Cambridge.

Oates, J.F. and Davies, A.G. 1994. What are colobines? in Colobine Monkeys: Their Ecology, Behaviour and Evolution. eds. A.G. Davies and J.F. Oates. Cambridge University Press: Cambridge.

Rowe, N. 1996. The Pictorial Guide to the Living Primates. Pogonias Press: East Hampton, New York.

van Schaik, C.P., Assink, P.R., and Salafsky, N. 1992. Territorial behavior in southeast Asian langurs: Resource defense or mate defense? American Journal of Primatology. Vol. 26, 233-242.

Wilson, C.C. and Wilson, W.L. 1976. Behavioral and morphological variation among primate populations in Sumatra. Yearbook of Physical Anthropology. Vol. 20, 207-233.

Last Updated: October 12, 2003.
[The Primata] [Primate Fact Sheets] [Subfamily Colobinae] [Presbytis Links]