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 the golden-yellow crest that darkens down to the shoulders. Males weigh on average 8-9.5 kilogram and females 6.7-8 kilogram; the average head and body length for both sexes is 53 centimeter. Females possess a distinctive ‘pubic patch’ of white fur and pale skin anterior to the callosities.
The Cat Ba Langur lives in the 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.
HABITAT AND ECOLOGY
The species is endemic to Vietnam and only occurs on Cat Ba Island in Ha Long Bay
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 assessed as Critically Endangered (IUCN, 2015) in the International Union for Conservation of Nature’s Red List of Threatened Species and in the Vietnam Red Book. In 2016-2018, the IUCN included the Cat Ba langur in its list of the 25 most imperiled primate species. and then again in the 2018-2020 report.
The Cat Ba langur population in the 1960s was estimated to have been between 2,400 and 2,700 individuals. By the year 2000, the population had been devastated and reduced to less than 135 individuals. Today, the population counts 65-67 individuals and is slowly rising.