White Fronted Leaf-monkey (Presbytis frontata)


MORPHOLOGY:
The white fronted leaf-monkey has a tall sagittal crest that leans forward. This species has a sacculated stomach to assist in the breakdown of cellulose. The white fronted leaf-monkey has enlarged salivary glands. 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 head of this species is colored black and has a crest (Rowe, 1996). The dorsal side is pale grayish brown and the ventral side is yellowish brown in coloration (Groves, 2001). The tail of the white fronted leaf-monkey is yellowish gray (Groves, 2001). The hands, feet, brow, crown crest, and cheeks are blackish in coloration (Groves, 2001). There is a light colored frontal patch on the crown crest (Groves, 2001). The average body mass for an adult male is 5.67 kilograms and for adult females it is 5.56 kilograms (Fleagle, 1999).

RANGE:
The white fronted leaf-monkey is found on the island of Borneo, in the countries of Indonesia and Malaysia. This species is found in lowland rainforests, not above 300 meters. This species has also been observed in riverine and hill forests (Azuma et al., 1984).

ECOLOGY:
The white fronted leaf-monkey is primarily a folivorous species, but will also consume fruits and seeds. This species prefers to eat immature leaves to more mature ones. Group sizes range from 10 to 15 individuals. Suzuki (1984) found that in Kutai Nature Reserve the group size for the white fronted leaf-monkey ranges from 2-10 individuals. This is an arboreal and diurnal species.

LOCOMOTION:
The white fronted leaf-monkey moves through the forest quadrupedally (Fleagle, 1988). This species also moves through the forest by leaping (Fleagle, 1988).

SOCIAL BEHAVIOR:
Solitary males have been observed in this species (Suzuki, 1986).

VOCAL COMMUNICATION:
loud call: This is emitted by males and is used to demarcate the group's territory.

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 white fronted leaf-monkey gives birth to a single offspring.

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

Azuma, S., Suzuki, A., and Ruhiyat, Y. 1984. The distribution of primates in Sebulu and R. Mahakan. Kyoto University Overseas Research Report of Studies on Asian Non-human Primates. Vol. 3, 45-54.

Burton, F. 1995. The Multimedia Guide to the Non-human Primates. Prentice-Hall Canada Inc.

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

Fleagle, J. G. 1999. Primate Adaptation and Evolution. Academic Press: San Diego.

Groves, C.P. 2001. Primate Taxonomy. Smithsonian Institution Press: Washington, D.C.

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.

Suzuki, A. 1984. The distribution of primates and the survey on the affection of forest fires, 1983, in and around Kutai Nature Reserve of East Kalimantan, Indonesia. Kyoto University Overseas Research Report of Studies on Asian Non-human Primates. Vol. 3, 55-65.

Suzuki, A. 1986. The ecological survey on the effects of the forest fires and droughts in 1982-83, and the distributions and populations of primates along the middle-upper streams of Sungai Sengata in Kutai National Park, East Kalimantan, Indonesia. Kyoto University Overseas Research Report of Studies on Asian Non-human Primates. Vol. 5, 13-22.

Last Updated: June 21, 2007.
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