Male and female Cat Ba langurs have a similar appearance, but vary slightly in size. The body is a dark chocolate brown to black with a silvered band of hair forming a 'V' that runs from the thighs up to the base of the tail. On the head the hair forms a yellowish white to golden-yellow crest which darkens down to the shoulders. Males weigh on average 8-9.5 kg and females 6.7-8 kg, the average head and body length for both sexes is 53cm. Females possess a distinctive 'pubic patch' of white fur and pale skin anterior to the callosities.
HABITAT AND ECOLOGY
The species is endemic to Vietnam and only occurs on Cat Ba Island in Halong Bay.
The Cat Ba langur lives in forest on karst hills. They are mainly folivorous, with leaves making up between 60-80 % of its diet and the rest composed of shoots, fruit, flowers and bark. Group size is variable, but generally consists of one adult male, multiple females and offspring.
Hunting for meat and traditional medicine has been identified as the cause of the rapid decline of this species over the previous decades. With a population likely to be less than 60 individuals the greatest threat now is the small population size.
STATUS AND CONSERVATION
The Cat Ba Langur is listed as Critically Endangered in the 2007 Vietnam Red Data Book and is protected by law under Decree 32/2006 ND-CP:1B.
CITES Appendix II- International trade must be controlled in order to avoid utilisation incompatible with their survival.
The species is now managed under the Cat Ba Langur Project and occupies an area of high protection.