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

3.3 CAT BA LANGUR - Trachypithecus poliocephalus poliocephalus
3.3 Cat Ba langur
Trachypithecus poliocephalus poliocephalus (Trouessart, 1911)
3.3.1 Taxonomy
The Cat Ba or Golden-headed langur was described as a new species, poliocephalus, of the genus
Semnopithecus by Trouessart (1911) on the basis of a single adult female skin. The skin was donated
to the Museum National d’Histoire Naturelle, Paris. Subsequently, this primate taxon has been placed
as a species in several genera: Pithecus poliocephalus (Thomas, 1928), Trachypithecus poliocephalus
(Pocock, 1935), and Pygathrix poliocephalus (Rode, 1938).
Ellerman and Morrison-Scott (1951) grouped this taxon with the Delacour’s langur and the Lao
langur as a subspecies of the Francois’ langur: Presbytis francoisi poliocephalus. Many authors follow
this decision although they sometimes alter the generic classification to either Trachypithecus francoisi
poliocephalus (Napier & Napier, 1967; Eudey, 1987) or Semnopithecus francoisi poliocephalus (Corbet
& Hill, 1992).
Due to the existence of a similar grey-coloured terminal band on the rump and outer sides of the
thighs, Brandon-Jones (1984, 1995) considered poliocephalus to be a subspecies of the Hooded leaf
monkey Semnopithecus johnii from South India, although the two species differ in many other ways.
This grouping is largely unaccepted.
Roos et al. (2001) found clear differences in genetics and proposed to separate poliocephalus as a
distinct species with the Chinese White-headed langur leucocephalus as subspecies. This classification
is also considered by Groves (2001).
3.3.2 Description
The pelage of adult males and females is dark chocolate-brown, not black as in francoisi and laotum.
The head and neck, down to the shoulders, are bright golden-brown to yellowish-white with the head
and crest being the most light coloured parts. The species has a 5cm-wide grey band which runs
from the thighs to the back, above the root of the tail. This band forms a V-shape, with the tip on the
lower back. The hairs of the band are dark brown in color, like the rest of the back, but about 5 to
10mm of the tips are bright silver-grey, giving the band a “frosted” appearance. The feet and hands
have a small yellow patch, which is the same color as the shoulders. Females have a pubic patch with
pale hairs; they also often have skin patches with irregular pigmentation in the pubic area. Like
francoisi the Cat Ba langur has very long hair on his “back cape” with a hair length up to 180mm. All
bare skin, including the skin of the face, ears, hands and feet, is black.
External measurements (adult)
n mm average Source
Head/Body length
male 3 492- 590 537 Brandon-Jones, 1995
female 2 495- 550 523 Brandon-Jones, 1995
Tail length
male 3 820-872 854 Brandon-Jones, 1995
female 2 820-887 854 Brandon-Jones, 1995
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