The East Javan langur (Trachypithecus auratus), also known as the ebony lutung, Javan langur or Javan lutung
The East Javan langur (Trachypithecus auratus), also known as the ebony lutung, Javan langur or Javan lutung, is an Old World monkey from the Colobinae subfamily. It is most commonly glossy black with a brownish tinge to its legs, sides, and "sideburns". It is found on the island of Java, as well as on several of the surrounding Indonesian islands. The Latin word auratus in its scientific name means "golden", and refers to a less common colour variant. Note that the common name golden langur is used for a different species.
Trachypithecus auratus is a species of catarrhine primate in the family Cercopithecidae.
Habitat
Trachypithecus auratus inhabits the islands of Java, Bali, the Indonesian island of Lombok, the inland forests of western Indonesia and the southern coast. Trachypithecus auratus lives in various forest habitats: mangrove forests, beaches, freshwater marshes, lowland and hill forests, as well as mountain forests up to 3500 m altitude.
Appearance and nutrition
These monkeys have a body length of 44-65 cm, with a tail (61-87 cm) longer than the body, and weigh about 7 kg. Trachypithecus auratus feeds mainly on leaves and flowers. Its enlarged salivary glands and complex stomach are well adapted to this plant-based diet. They also eat ripe and immature fruits and insect larvae.
The diet of Trachypithecus auratus consists of 15-27% immature fruit and 10-12% ripe fruit. Often monkeys eat fruit primarily to obtain seeds from it. Trachypithecus auratus prefers leaves rich in protein and low in fibre. Interestingly, several groups of Trachypithecus auratus can feed on the same food source without aggression.
Reproduction
These monkeys usually choose one mate for life. Pregnancy lasts an average of six to seven months for a female, and a young is born. At one year of age, it stops feeding on milk and reaches sexual maturity at three to six years of age. Trachypithecus auratus pups are born bright red, but darken with age until their fur is almost black. However, this is not always the case; some monkeys remain red-haired for life.
Trachypithecus auratus on the Red List
Numbers of Java langurs are declining as a result of human activities: habitat loss due to agricultural expansion, hunting and illegal trade. Trachypithecus auratus is listed as vulnerable on the IUCN Red List.
Subspecies
Formerly there were two subspecies of Trachypithecus auratus recognised:
- Eastern Javan langur or spangled ebony lutung, Trachypithecus auratus auratus;
- Western Javan langur, Trachypithecus auratus mauritius.
Roos et al., 2008, elevated T. a. mauritius to a separate species as Trachypithecus mauritius.
