silvered leaf monkey
Trachypithecus cristatus
Summary 3
The silvery lutung (Trachypithecus cristatus), also known as the silvered leaf monkey or the silvery langur, is an Old World monkey. It is arboreal, living in coastal, mangrove, and riverine forests in Peninsular Malaysia, Sumatra, and Borneo.
Habitat 4
The habitat of T. cristatus is very similar to that of other members of its subfamily Colobinae. Silvered leaf monkeys primarily inhabit dense forests, but their habitat can vary somewhat depending on the region. In Java and Sumatra, they live in the trees of inland forests, whereas on the Malaysian Peninsula, they live in the mangrove and sub-coastal forests. They have also been found in bamboo forests, on plantations, and in swamp forests. Because the monkeys are largely arboreal, they rarely leave the trees. Occasionally, they come down to the ground, but retreat quickly if there is a threat of danger.
Habitat Regions: tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest ; scrub forest
Wetlands: swamp
Other Habitat Features: agricultural
Physical description 5
Trachypithecus cristatus is similar in appearance to other colobines in that it is small in size, has a long tail, and dense fur. Also common to colobines is an under-bite in which the lower jaw projects out further than the upper jaw. The genus Trachypithecus is distinguished from other colobines by its prominent nasal bones, a well-developed coronal crest, and poorly developed brow ridges. There is also a reduction in the size of the first digit (thumb) facilitating the brachiating movements they utilize. The fore and hind limbs are more equal in length than most other cercopithecids, or Old World Monkeys, suggesting that the group previously occupied a more terrestrial habitat.
Silvered leaf monkeys get their name from the coloring of their pelage. There is some variation in the color of their fur, including brown, gray, brownish-gray, or black. No matter what the color, some hairs are gray-white and give a silver appearance. Polymorphisms are very rare; the best known is a red morph that exists in Borneo. The hands and feet are prehensile, hairless, and usually black in color. Males and females are difficult to distinguish from one another. The only visible difference is irregular white patching on the inside of the flanks of females. Males are also slightly larger than females: females are 89% of the body weight of the males.
Newborns have orange fur and white colored hands, feet, and face. The skin changes color within days of birth to black, as in the adults of this species. The orange fur changes to the adult color within three to five months.
Body length in males ranges from 52.4 cm to 56.0 cm, whereas females are typically 46.5 cm to 49.6 cm. Both sexes have a tail that is longer than their body; tail length ranges from 63 cm to 84 cm. Male body weight averages 7.1 kg and female body weight is about 6.2 kg. Newborns are about 20 cm and 0.4 kg at birth. They reach their adult size at about 5 years of age.
Range mass: 4.9 to 8.0 kg.
Average mass: Male: 7.1; Female: 6.2 kg.
Range length: 46.5 to 56.0 cm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike; male larger
Sources and Credits
- (c) Wally Gobetz, some rights reserved (CC BY-NC-ND), http://www.flickr.com/photos/70323761@N00/469540006
- (c) Peter Gronemann, some rights reserved (CC BY), http://www.flickr.com/photos/39463459@N08/7604299102/
- Adapted by Brian Martin from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Trachypithecus_cristatus
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18677247
- (c) The Regents of the University of Michigan and its licensors, some rights reserved (CC BY-NC-SA), http://eol.org/data_objects/18677248
