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The Cat Ba
Langur |
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A
Extraordinarily Beautiful Primate |
Identification of the Cat Ba Langur
As indicated by this species former name (the Golden-headed
langur), head and neck down to the shoulders are bright golden
to yellowish-white, with the head and the crest being most
brightly coloured. The rump and the extremities of adult males
and females of the Cat Ba langur are covered by dark chocolate
brown, almost black fur. A grey band runs from the thighs to
the back, forming a V-shape above the tail root and long hair
of the back forms a shoulder cape. Another prominent feature
of all Trachypithecus langurs is their long tail. Its
length clearly exceeds head-body length.
The only difference in the colouration between the
sexes is a white pubic patch on the female. The infant coat
colouration of the Cat Ba langur as well as of the other
Trachypithecus species in Vietnam is a flamboyant orange.
Distribution of the Cat Ba Langur and Ecology
The only known locality of where this langur occurs is the
island of Cat Ba. There is no evidence that the Cat Ba langur
ever inhabited the mainland. Immigration of this species onto
Cat Ba Island might have taken place long before the sea level
rose due to a melting of glacial ice. The last time this
melting happened was some 10,000 years ago and it turned the
former mountainous Ha Long Bay into a huge Archipelago.
The Cat Ba langur along with two of its close relatives, the
Francois’ langur (Northern Vietnam and southern China) and the
White-headed (southern China), are closely associated with
limestone areas. These langur species prefer Karst and forest
on limestone as habitat and regularly sleep in caves
throughout the year. Scientists suggest that caves and cracks
are important as shelter against unfavourable weather
conditions. One langur group usually has several (up to 12)
different resting caves. The group spends only 1-2 nights in
the same cave before moving on to other feeding and sleeping
places.
A significant proportion of a langurs’ daily life is devoted
to foraging and resting. The diet of the Cat Ba langur mainly
consists of leaves, but also includes fresh shoots, flowers,
bark and some fruits that are not palatable to human beings.
Most of the langur’s food has very high concentration of fibre
and tannic acids, and often contains substances that would be
poisonous to other animals, including human beings.
Threat Status
The World Conservation Union (IUCN) lists the Cat Ba langur as
one of the most critically endangered primate species of the
World, due to its small population size and restricted range.
Only 65 langurs currently survive in the wild whilst an
additional two live in the
Endangered Primate Rescue Centre
at Cuc Phuong National Park.
In the past, poaching constituted the primary threat to langur
survival and resulted in a population decline from estimated
2,500-2,800 individuals in the 1960s, to a mere 53 individuals
by 2000.
As a result of this steep decline in numbers, the remaining
langur population is now highly fragmented and low
reproductive output threatens their future survival. The
population of the Cat Ba langur is subdivided into seven
isolated sub-populations. Some of these include all-female
groups and are therefore non-reproducing social units. Langurs
were mainly poached for the preparation of traditional
medicine, referred to as “monkey balm”, and only rarely for
use as food, as their meat has a very unpleasant smell.
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Photo: Stefan Kobold
The Cat Ba Langur is a member of a
primate subfamily that is referred to as leaf-eating monkeys
(Colobinae), due to their food preferences
Photo Courtesy of Bavarian TV
A Group of Cat Ba Langurs
Like most Colobines,
the Cat Ba Langur is a tree dweller and lives in social groups
with one male and several females
Sleeping site of the Cat Ba langur - a
limestone cave
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