East Javan langur, Ebony lutung, Javan langur
The Javan lutung (Trachypithecus auratus) is a species of Old World monkey. The Latin word auratus in its scientific name means "golden", and refers to a less common color variant. The Javan lungur has a specialised stomach to digest plant material more efficiently. This species also has enlarged salivary glands to assist it in breaking down food.
The two subspecies of the Javan lutung are fairly similar in appearance and are geographically separated; males and females are both usually glossy black, although the females have a pale, yellowish-white patch around the pubic area. Juveniles of both subspecies are orange in color. The nominate subspecies Trachypithecus auratus auratus has a rare morph that does not lose its juvenile coloration when it matures, instead, the coloration darkens slightly, with yellow tinges on its sides, limbs, and around its ears, and a black tinge on its back.
These lutungs are found on the island of Java, as well as on several of the surrounding Indonesian islands. They live in rainforests, mangroves, swamp forests, and lowland and montane forests.
Javan lutungs are diurnal and arboreal monkeys that spend most of their time in trees. They live in groups of around 7 individuals, with one or two adult males in the group. Although 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.
Javan lutungs are polygynous; they don't form pairs and one male mates with more than one female. These monkeys do not have a certain period for mating season and females produce one offspring at a time. The infant is born precocial; it develops quickly and becomes independent within 1 year after birth. Young females usually become reproductively mature and begin to breed around 3 to 4 years of age.
Javan lutungs are threatened by the illegal pet trade and hunting for food and local medical purposes. These animals also suffer from the continuing loss of their native habitat.
The IUCN Red List and other sources don’t provide the number of the Javan lutung total population size. Currently, this species is classified as Vulnerable (VU) on the IUCN Red List, and its numbers today are decreasing.