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:
Mitered Leaf-monkey



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:

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: June 21, 2007.
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