About Trachypithecus auratus (É.Geoffroy Saint-Hilaire, 1812)
Like all langurs, this species has a noticeably long tail that can reach 98 cm in length, while its body is only around 55 cm long. This monkey has two subspecies, which are fairly similar in appearance and geographically separated from one another. Both males and females are usually glossy black, but 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 orange coloration as 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. East Javan langurs inhabit the interior and peripheral areas of rainforests. This primate is diurnal and arboreal. Its diet is primarily herbivorous, consisting of leaves, fruit, flowers, and flower buds, although it also eats insect larvae. As with other colobines, it has evolved a specialized stomach to digest plant material more efficiently. This species also has enlarged salivary glands to help break down food.