Order : PRIMATES
Family : Cercopithecidae
Species : Trachypithecus auratus

Head-body length : 44-65 cm
Tail length : up to at least 90 cm
Weight : up to 7 kg

The Javan Lutung, or Ebony Leaf Monkey, is a relatively uncommon species of langur whose population, in recent years, has been classified as by IUCN (Nijman, 2021) as 'vulnerable' to 'endangered'. Its numbers are declining steadily due to habitat loss, hunting and illegal capture for the pet trade.

The word Lutung is an Indonesian word applied to leaf monkeys in general.

In the lowlands of Java it still survives in a range of habitats including mangrove, freshwater swamp forest and remnant tall, lowland forest. In the hills and mountains it survives up to 3500 metres above sea level in tall, primary forest which is now largely confined to the slopes of volcanoes and upland plateaus. It is also reported from teak and acacia plantations, which implies that the species may be reasonably adaptable. However, its range is considered highly fragmented.

The fur of adults is a deep, glossy black with sometimes a slight brownish tinge. The face and feet and dark grey to black. Juveniles are bright orange, and in some parts of Java there is a rare form in which the fur is orange into adulthood.

This leaf monkey feeds mainly on fresh, young leaves, as well as flowers and fruits.

Two subspecies are sometimes described, but there appears to be little genetic support for this assertion.

The Javan Lutung occurs on the islands of Java,  Bali and nearby, smaller islands. A small population also occurs on the island of Lombok, to the east of Bali. Lombok lies on the easterly side of the Wallace Line, across which primates are unlikely to have naturally migrated. Thus, the Lombok population may have become established from individuals  introduced by man in historical times.

Fig 1 : Young adult with typical jet black fur, in secondary forest.

Fig 2 : Adult with juvenile hiding amongst dense vegetation in the mid-canopy of secondary forest.

Figs 3 and 4 : Young adult seen feeding amongst secondary vegetation.

All images from the slopes of Mount Rinjani on Lombok Island, Indonesia.


References :

Nijman, V. 2021. Trachypithecus auratus. The IUCN Red List of Threatened Species 2021: e.T39848A17988500.