Golden Langur

**Gee's golden langur** (*Trachypithecus geei*), or simply the **golden langur**, is an Old World monkey found in a small region of western Assam, India and in the neighboring foothills of the Black Mountains of Bhutan. It is one of the most endangered primate species of India. Long considered sacred by many Himalayan people, the golden langur was first brought to the attention of the western world by the naturalist E. P. Gee in the 1950s. In a part of Bhutan, it has hybridised with the capped langur *T. pileatus*.

## Distribution and Habitat

Gee’s golden langur (*Trachypithecus geei*) is found along the border between India and Bhutan, where it has learned to accommodate a range of environments and altitudes. Specifically, golden langurs inhabit a region marked by four distinct geographical points: in the north, the foothills of Bhutan; in the south, the Brahmaputra River; in the east, the Manas River; and in the west, the Sankosh River.

The golden langur population is highly fragmented, especially in India, where southern populations are isolated from northern populations due to human activity. In 2003, researchers identified a new subspecies, *T. g. bhutanensis*, for the Bhutan golden langurs who live in northern regions that are separated by geological features in the Himalayan mountains. The subspecies, however, has not been officially recognized due to a conflict with the International Commission on Zoological Nomenclature’s rules that govern the describing of species.

The total range for golden langurs in both countries spans less than 11,600 sq mi (30,000 sq km), and despite this species’ versatility, much of its range does not provide suitable habitat. Highly dependent on trees, golden langurs prefer the upper canopies of moist evergreen, riverine, dipterocarp, and tropical deciduous forests, but researchers also note that these monkeys will inhabit degraded and altered habitats, including secondary forests and fragmented forests. They also adapt to a wide range of elevations, surviving at near sea-level in southern areas to above 9,800 ft (3,000m) in northern areas.

## Diet

As with many other species of langur, the golden langur is known as a leaf monkey—and he’s built specifically to eat and digest large amounts of leafy material. Like other Old World monkeys belonging to the Colobinae subfamily, the golden langur comes equipped with a compartmentalized sacculated stomach that helps to break down the hard-to-digest cellulose in leaves, a process essential to extracting the most nutrients as possible. In addition to enjoying both young and mature leaves, the golden langur happily dines on ripe and unripe fruits, leaf buds, flower buds, seeds, twigs, and flowers. Early observations of golden langurs also suggest he can withstand habitat change; in fragmented forests, golden langurs have been known to seek cultivated crops, like guava and tapioca, as food sources.

## ​Behavior and Lifestyle

Considered very rare and highly secretive, golden langurs are one of primatology’s more recent discoveries (the species was first classified in 1956). As a result, the species has not yet been well studied. Researchers note that unlike the abundant Hanuman langurs (*Semnopithecus entellus*), who appear unafraid of humans, golden langurs work hard to avoid human contact, making observations of their behaviors and lifestyle challenging.