Order : PRIMATES
Family : Cercopithecidae
Species : Trachypithecus hatinhensis

Head-body length : 50-66 cm
Tail length : 81-87 cm
Weight : Up to 8.7 kg

The Hatinh Langur, or Stripe-headed Black Langur, inhabits forested areas on steeply sloping hills, particularly in areas of karst limestone in parts of Vietnam and Laos. Typically, karst limestone outcrops are steep-sided, often with near-vertical cliffs, and such hills may provide a safe haven for primates, free from hunting and other human persecution.

This endangered species occurs at elevations of up to 1500 metres, and is both arboreal and terrestrial. It subsists mainly on fresh, young leaves of various tree species. Group sizes typically range from 2 to 15 individuals, though larger groups are sometimes seen.

This langur is in the habit of roosting overnight in small limestone caves, sheltered crevices and rocky overhangs, in contrast to other species of langur which tend to roost in trees. Most individuals sleep alone, though adult pairs may sleep near each other. Roosting sites typically face west or south-west, which are warmed by the afternoon sun, and may offer shelter from cold northerly winds in the winter (Nguyen, 2006).

Adults have a distinctive white facial marking comprising a thin moustache, which extends to the corner of the mouth, above the ears and ends at the nape. The rest of the fur on the head is black, with a pronounced and distinctively shaped crest. The body fur is black and very glossy throughout. Newborn infants are yellowish-orange, but this colour starts to fade in a matter of weeks, and by 3 months they are entirely black.

Some primatologists consider the Hatinh Langur to be a subspecies of the Lao Langur Trachypithecus laotum. Groves (2001), however, treats the Hatinh Langur as a separate species. It occurs in parts of eastern Laos, and the Annamite Mountains in north-central Vietnam.

Figs 1 and 2 : This group of Hatinh Langur were spotted around 9 a.m. in the morning, foraging amongst fresh, young leaves.

All photos extracted from video taken in Phong Nha-Ke Bang National Park, Quang Binh Province, Vietnam by Andie Ang.


References :

Quyet, L.K., Coudrat, C.N.Z., Phiaphalath, P., Nadler, T. & Covert, H. 2021. Trachypithecus hatinhensis (amended version of 2020 assessment). The IUCN Red List of Threatened Species 2021: e.T40789A196139355.

Francis, C.M. 2019. A Field Guide to the Mammals of South-east Asia. Second Edition. New Holland. 416 pp.

Groves, C. P. (2001). Primate taxonomy. Smithsonian Institution Press, Washington DC. 350 pp.

Nguyen, M. H. 2006. Some Observations on the Hatinh langur, Trachypithecus laotum hatinhensis (Dao, 1970), in North Central Vietnam. Primate Conservation.  21: 149–154