Trachypithecus cristatus (Raffles, 1821)

Russell A. Mittermeier, Anthony B. Rylands & Don E. Wilson, 2013, Cercopithecidae, Handbook of the Mammals of the World – Volume 3 Primates, Barcelona: Lynx Edicions, pp. 550-755 : 743

145.

Silvered Langur

Trachypithecus cristatus

French: Langur a coiffe / German: Grauer Haubenlangur / Spanish: Langur plateado

Other common names: Silvered Leaf Monkey, Silvered Monkey, Silvery Langur, Silvery Lutung; Miller's Silvered Langur (vigilans)

Taxonomy. Simia cristata Raffles, 1821 ,

Indonesia, Sumatra, Bencoolen (= Bengkulu).

T. selangorensis was first described as a subspecies of T. cristatus , but is now considered a distinct species. T. cristatus is closely related to T. auratus , T. mauritius , T. germaini , 1. margarita , and T. selangorensis , and together they form the cristatus species group. Two subspecies are recognized, although they are genetically very similar.

Subspecies and Distribution.

1. c. cnistatus Raffles, 1821 — Borneo, Sumatra, Bangka, Belitung, and Riau (Bintan, Combol, Sugi, and perhaps Batam) and Lingga (Bakung, Lingga) Archipelagos, off E Sumatra.

1: c. vigilans G. S. Miller, 1913 — Natuna Is (Serasan I), off W Borneo.

Descriptive notes. Head—body 50-58 cm (males) and 46-51 cm (females), tail 67— 75 cm (males) and 66-75 cm (females); weight ¢.6-6 kg (males) and ¢.5-7 kg (females). The Silvered Languris variable in color. Circumfacial hair is erect and forward-curled, there is a high pointed crest (but less pointed and high that in the Selangor Silvery Langur, 1. selangorensis ), and face is slaty-black. Adult female Silvered Langurs have irregular patches of white on inner parts of upper thighs. Teeth and jaws are relatively short. The nominate subspecies cristatus can be divided into two main morphs, which are very distinct but not genetically and geographically separated (although they are somewhat more so in Sumatra). The silvery-gray “wltimus” morph predominates in northern Sumatra;it is uniformly dark gray, tipped with paler gray;it has a black-tinged forehead and yellowish groin and underside oftail. The “ cristatus ” morph has shorter hair tips, especially on its back, giving it an overall almost gray-green color. It occurs further south on Sumatra and on Bangka, Belitung, and Riau Islands. Both morphs occur at almost equal frequencies in Borneo, with the “ cristatus ” morph being perhaps slightly more common. There is an additional, rare reddish morph in Sabah, Borneo. “Miller’s Silvered Langur” (7. c. vigilans) is rather darker than the nominate subspecies, with less lightened hair tips. Its crown is dark and surrounded by a well-defined zone of long hair tips.

Habitat. Primary and secondary forests including coastal, montane, mangrove, swamp, and riparian forest in Sumatra and mainly riparian and mangrove forests in Borneo. The Silvered Langur is sometimes found in plantations. Depending on the region,it is sympatric with different species of Presbytis .

Food and Feeding. There is no information available for this species.

Breeding. The Silvered Langur is not a seasonal breeder. The gestation period averages 194-6 days, and the ovarian cycle lasts c.24 days. It usually has singletons (twins are rare). Newborns are golden-orange in color, with white on the hands, feet, and face. [ts coat gradually changes to grayish at 3-5 months of age. Allomothering is common.

Activity patterns. There is no information available for this species.

Movements, Home range and Social organization. There is no information available for this species.

Status and Conservation. CITES Appendix II. Classified as Near Threatened on The IUCN Red List, including the nominate subspecies cristatus , but the subspecies vigilans is classified as Critically Endangered. Major risks for Miller’s Silvered Langur are its restricted distribution (only 62 km* on Serasan Island) and ongoing loss of suitable habitat due to deforestation. The nominate subspeciesis still wide-ranging, but it too is suffering from habitat loss throughoutits range. On Borneo, threats are mainly due to land clearance (oil palm plantations), and forest fires. Silvered Langurs are hunted for their meat in Sarawak and are often kept as pets in Sumatra. The nominate subspecies occurs in various protected areas, including Bukit Barisan Selatan and Gunung Leuser national parks in Indonesia and Bako National Park in Malaysia. An overall population estimate is not available.

Bibliography. Groves (2001), Harding (2010), Hooijer (1960), MacKinnon & MacKinnon (1987), Maryanto et al. (1997), Nijman & Meijaard (2008b), Roos et al. (2008), Shelmidine, Borries & Koenig (2007), Shelmidine, Borries & McCann (2009), Weitzel et al. (1988).

Figures

140. Golden Langur (Trachypithecus gee), 141. Capped Langur (Trachypithecus pileatus), 142. Shortridge’s Langur (Trachypithecus shortridgei), 143. East Javan Langur (Trachypithecus auratus), 144. West Javan Langur (Trachypithecus mauritius), 145. Silvered Langur (Trachypithecus cristatus), 146. Selangor Silvery Langur (Trachypithecus selangorensis), 147. Germain’s Langur (Trachypithecus germaini), 148. Annamese Langur (Trachypithecus margarita)

Subspecies and Distribution. 1. c. cnistatus Raffles, 1821 — Borneo, Sumatra, Bangka, Belitung, and Riau (Bintan, Combol, Sugi, and perhaps Batam) and Lingga (Bakung, Lingga) Archipelagos, off E Sumatra. 1: c. vigilans G. S. Miller, 1913 — Natuna Is (Serasan I), off W Borneo.