Vietnam Primate Conservation Status Review 2002 - Hoang Lien ...

3.2 Hatinh langur
Trachypithecus laotum hatinhensis (Dao, 1970)
3.2.1 Taxonomy
3.2 HATINH LANGUR - Trachypithecus laotum hatinhensis
The Hatinh langur was described by Dao Van Tien (1970) as a sub-species of T. francoisi, based on
two specimens collected in 1942 and 1964. The type was reported from Xom Cuc, in Quang Binh
Province near its border with Ha Tinh. (The occurrence of Hatinh Langur in the latter province has
never been confirmed). Most authors have agreed with this taxonomy. Groves (2001) placed the
langur as a distinct species. However, a recent taxonomic review, based on genetic evidence, would
separate hatinhensis from francoisi and include it as subspecies of T. laotum (see 2.3, Roos, 2000;
Roos et al., 2001).
T. l. hatinhenisis is a dimorph taxon with (partly) geographically separated but not reproductively
isolated forms and intergradation.
In 1924, F. R. Wulsin (Thomas, 1928) collected the skin and skull of an all-black langur, now in the
Smithsonian Museum (USNM 240489). The locality “French Indo-China” does not indicate its true
provenance. Brandon-Jones (1995) speculates that the animal originated from the Fan Si Pan area in
North Vietnam and allocates it to the Indonesian Ebony langur Semnopithecus auratus, which is also
black, as a new subspecies S. a. ebenus.
In January 1998 the EPRC received an all-black langur which came presumably from the Hin Namno
area in Lao (Nadler, 1998).
Anatomical features, behaviour and vocalization of this animal show strong affinities to the Hatinh
langur. The Black langur does not differ in colouration, hair structure, whorls and shape of the crest
from the Hatinh langur. The moustache and the cheeks are black but the hair structure is different,
with the hairs being more wavy and marking the parts between the corner of the mouth and the ears.
Brandon-Jones’ (1995) detailed description of the hair structure, hair direction and colouration of
the specimen in the Smithsonian Museum corresponds closely to the animal at the EPRC and differs
clearly from the Ebony langur.
The geographical separation also suggests that the Black langur is not a subspecies of the Ebony
langur, which is distributed on the islands Java, Bali and Lombok. Finally the itinary of Wulsin’s
expedition suggests that the type was actually collected in the Hin Namno area as well, and not in
northern Vietnam as originally assumed.
Based on the corresponding morphology and molecular genetic of the type specimen and the living
animal at the EPRC, they are most probably of the same origin.
Recent genetic studies have shown that the Black langur is only an melanistic morph of the Hatinh
langur (see 2.3). This is also supported by field observations, in that both morphs are present in the
same region (Ruggieri & Timmins, 1995).
3.2.2 Description
The Hatinh langur differs from Francois’ langur in the extent of the white cheek stripe behind the ear
onto the nape. Other differences include the whorls on the head and the shape of the crest, and a white
moustache connecting the white cheek stripes (Nadler, unpubl.). The nominate form T. l. laotum (Thomas,
1921) from Ban Na Xao, Lao PDR (ca. 17°30’N) has a white head with a black crest and brow band.
Furthermore, an all-black form T. laotum ebenus (see below) has also been described from this region.
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