The Javan lutung, Trachypithecus auratus also known as the Ebony lutung and Javan langur, is an Old World monkey from the Colobinae subfamily. It is 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.
Like all langurs, this species’ tail is noticeably long. It measures up to 34.25 inches (87 cm) long while the body is only around 21.65 inches (55 cm) long. The two subspecies of this lutung are fairly similar in appearance and are geographically separated. The males and females are both usually glossy black. The females have a pale, yellowish white patch around the pubic area. Juveniles of both subspecies are orange in color. The nominate subspecies has a rare race that does not lose its juvenile coloration when it matures. The coloration darkens slightly, with yellow tinges on its sides, limbs, and around its ears. It has a black tinge on its back.
The Javan lutung inhabits the interior and peripheral areas of rainforests.
This primate is a daytime animal and lives in the trees. Its diet is primarily herbivorous. It eats leaves, fruit, flowers, and flower buds, although it also eats insect larvae.
The Javan lutung is a social animal, living in groups of around seven individuals. It has one or two adult males in the group. They will look after offspring of other mothers as well as their own. Adult females are aggressive towards females from other groups. The brighter coloring of juveniles may alert females to their presence and ensures that they will always be noticed and protected. This species has no discernable mating season and females produce one offspring at a time.