Trachypithecus ebenus (Brandon-Jones, 1995)

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 : 751-752

157.

Black Langur

Trachypithecus ebenus

French: Langur ébéne / German: Khammuan-Langur / Spanish: Langur negro

Other common names: Black Leaf Monkey, Indochinese Black Langur

Taxonomy. Semnopithecus (Trachypithecus) (auratus) auratus ebenus Brandon-Jones, 1995 ,

“Indo China” probably either Lai Chau or Fan Si Pan mountain chain (c.22° 30’ N, 103° 50’ E), Vietnam.

D. Brandon-Jones suspected the type locality of the holotype and sole recorded specimen was in the vicinity of Lai Chau, perhaps from the Fan Si Pan mountain chain, Vietnam. But there are strong indications that the specimen originated from central Laos. There is a contact zone, or even a small overlap, with 7. laotum in southern Phou Hi Poun National Protected Area, Laos. Black langurs in the southern part of Phou Hi Poun National Protected Area, Khammouane Province, and in limestone areas between this area eastwards on limestone blocks in the direction of Hin Namno, have a slightly different feature, with some white hairs around the pinna of the ears. The difference is hard to see in the field, but these animals also differ genetically from 1. ebenus and are possibly a distinct taxon. Monotypic.

Distribution. EC Laos, in S Khammouane Province, close to the border to Vietnam and in scattered limestone blocks to the S into N Savannakhet Province to ¢.16° 50° N, the speciesis also recorded in C Vietnam, Quang Binh Province (17° 59’ N, 105° 40’ E).

Descriptive notes. Head—body 62 cm, tail 94 cm; weight 10-3 kg (measurements only exist from only a single male specimen). Pelage of adult Black Langurs is completely black, with a brownish tinge. Hairs on head form a crest. One male at the Endangered Primate Rescue Center, Vietnam, was completely black as a subadult, but as he aged to more than ten years, he developed a gray shine from corners of mouth to ears and down to his nape, in contrast to the Hatinh Langur (7. hatinhensis ) that has a white line.

Habitat. Very steep and high limestone cliffs, most with sparse vegetation. Caves and crevices are used by Black Langurs as sleeping sites.

Food and Feeding. There is no specific information for this species, but Black Langurs are known to be folivores.

Breeding. The Black Langur has not been studied in the wild, but there are no differences between it and the Hatinh Langur in captivity. These langurs are born with a yellow-brown pelage but with individually variable parts of blackish shades on back, hips, and tail, which can be extensive in some individuals.

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

Movements, Home range and Social organization. Quadrupedalism is the most frequent form of locomotion. Due to their habitat, Black Langurs are much more terrestrial than Hatinh Langurs. The posture of the tail during running and jumping, a concave-upward tail inflection, corresponds with the other southern “limestone langurs,” the Hatinh Langur and the Laos Langur (7. laotum ) and differs from the northern species, Francois’s Langur (71. francoist), Delacour’s Langur (1. delacouri ), the White-headed Langur (7. leucocephalus ), and the Cat Ba Langur (7. poliocephalus ). The social structure of Black Langur groups is most probably very similar to that of the Laos Langur. Groups of 5-10 individuals have been seen in the wild.

Status and Conservation. CITES Appendix II. Classified as Endangered on The IUCN Red List (under T. hatinhensis ). Black Langurs are protected by law in Vietnam and Laos, but poaching in Laos is intensive. They occur in Hin Namno National Protected Area in Laos and Nui Giang Man Nature Reserve in Vietnam. Their inaccessible habitats provide for some protection.

Bibliography. Brandon-Jones (1995b), Duckworth, Boonratana et al. (2010), Duckworth, Salter & Khounbline (1999), Groves (2001), Le Khac Quyet (2004a), Nadler (1996/1997, 2009b), Nadler et al. (2003), Phiapalath (2010), Roos (2004), Stevens et al. (2008).

Figures

149. Tenasserim Langur (Trachypithecus barber), 150. Dusky Langur (Trachypithecus obscurus), 151. Phayre’s Langur (Trachypithecus phayrei), 152. Indochinese Gray Langur (Trachypithecus crepusculus), 153. Cat Ba Langur (Trachypithecus poliocephalus), 154. White-headed Langur (Trachypithecus leucocephalus), 155. Delacour’s Langur (Trachypithecus delacouri), 156. Francois’s Langur (Trachypithecus francoisi), 157. Black Langur (Trachypithecus ebenus), 158. Laos Langur (Trachypithecus laotum), 159. Hatunh Langur (Trachypithecus hatinhensis)

Distribution. EC Laos, in S Khammouane Province, close to the border to Vietnam and in scattered limestone blocks to the S into N Savannakhet Province to ¢.16° 50° N, the speciesis also recorded in C Vietnam, Quang Binh Province (17° 59’ N, 105° 40’ E).