Gee’s golden langurs, also known as golden leaf monkeys, or more simply as golden langurs, live in northeastern India and southern Bhutan. They are confined to this geographic region by the Manas and Sankosh rivers to the east and west, the Brahmaputra river in the south, and the Black Mountains to the north. Here, altitudes vary greatly; golden langurs may live anywhere between sea level and 9,800 feet (3,000 m) above sea level. This is a considerable range for primates.
This species thrives best high up in the canopies of subtropical and temperate broadleaf forests. However, golden langurs also make do in lowland evergreen, semi-evergreen, riparian moist deciduous forests, subalpine forests, and savannas, as well as secondary or degraded forests. A single, isolated population of golden langurs even lives in the Abhaya Rubber Plantation, in the Kokrajhar district in Assam, India, and has been the subject of a number of eye-opening studies into this shy and often elusive species.
The total amount of habitat considered suitable for golden langurs, in both India and Bhutan, has dropped significantly in the last several decades and now hangs at less than 193 square miles (500 km2).
Appearance
Golden langurs are easy to identify by their golden fur. Individual coats can range from dark gold to a creamy, buffy color. Their thick, wiry hair gives them a magical, almost other-worldly, countenance—like something out of the mind of Jim Henson (creator of the Muppets and Fraggle Rock). Tufts of gold-and-black-woven hair erupt from their faces like an exuberant wreath of solar flares, hiding their naked black ears.
Their lush golden coats of fur can’t quite hide golden langurs’ lanky limbs and slender frames. Long black fingers and toes extend visibly from their furry hands and feet. A signature tassel marks the ends of their majestically long tails.
Golden langurs’ coats change color with the seasons, darkening to a golden chestnut hue in the winter and lightening to a creamy tone in the summer. Populations in the south are also found to sport more uniform coats than in the north where there is greater variety.
Like other leaf-eating monkeys, the color of young golden langurs differs from that of adults. Like a marshmallow held over a flame, newborns start out with completely white fur that gradually goldens as they mature.
Size, Weight, and Lifespan
Tail length marks a considerable difference between the sexes. The average male golden langur sports a tail longer than his body, at 38 inches (97.5 cm) long, while an average female golden langur has a tail measuring only 34 inches (86.6 cm).
Golden langurs are relatively small primates, weighing between 19 to 26 pounds (9 to 12 kg). Males, measuring an average of 37 inches (95 cm) from head to butt, tend to be slightly larger than females at 35 inches (89 cm).
Male golden langurs also tend to have larger canine teeth, on average 0.7 inches (18 mm) in length versus a female’s half-inch (14.5 mm) fangs. For primates, the size of canine teeth can often predict the hierarchical relationships between the sexes.
A shy and elusive species that bolt at the sight of humans, researchers have a hard time tracking golden langurs over a long period of time. Therefore, it has been difficult to gather data on how long they live in the wild.
Diet
Golden langurs are primarily folivores, meaning they eat leaves. Though they chow down on a large variety at all stages of growth, softer, young leaves are clearly preferred over chewier, mature ones.
Fruit, both ripe and unripe, is another staple in this species’ diet. Certain seasonal fruits are one of the few items otherwise peaceful golden langurs regularly fight over. Certain flowers, especially the yellow buds and blossoms of the balu tree, are beloved as well. For some groups, leguminous shrubs provide tasty morsels worth the trip to the understory.
Golden langurs have also been observed eating lichens, algae, insect galls, bark, twigs, wild potatoes, insects (like termites), insect larvae, and snails. Some groups are known to raid local farms, attracted by their delicious cardamom, tapioca, and guava crops.
Golden langurs have specialized stomachs composed of multiple chambers. Each chamber helps to break down the tough fibers found in the leaves, bark, and whatever cellulose-rich plant material they may ingest. Though it makes digestion a long, drawn-out process, this important adaptation ensures the langurs obtain the maximum nutrition from every single meal.
Behavior and Lifestyle
Golden langurs are arboreal, living high in the canopy where they clamber up trees on all fours and make daring leaps between branches in order to get around. This lifestyle, plus their tendency to be quite secretive, makes them a difficult species to study in the wild. Groups often vacate an area as soon as humans show up. When a group chooses to stay put, the langurs’ obvious awareness of the researchers makes it impossible to judge how genuine and “natural” their behaviors really are.
These langurs seldom leave the safety of the canopy. They do so only when a large gap in the trees makes it completely necessary or if something particularly alluring (like natural salt licks) draws them down. Summer is the season when golden langurs visit the forest floor most often, doing so in order to hydrate themselves at watering holes on the forest floor. During wetter seasons, langurs are able to get all the water they need from the rain and moisture that condenses on the foliage of the canopy.
Golden langurs are not especially territorial monkeys. At times, groups may even mingle and mix. A group is most likely to defend its range when drought or another natural disaster has greatly reduced the amount of resources in the region. Defense, however, usually just means intimidation. Physical violence is practically unheard of in this species.
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