GEE'S GOLDEN LANGUR

Trachypithecus geei

Geographic Distribution and Habitat
The shy and highly endangered 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.

Gee's golden langur range, IUN 2020. Zoomed in.
Gee's golden langur range zoomed out. Range circled in red.

Size, Weight, and Lifespan
Golden langurs can grow to about 20-29 in (50-75 cm), with a tasseled tail extending another 28-40 in (70-100cm). Males tend to be slightly larger than females, weighing 24 lbs (10.8kg) to a female’s 21 lbs (9.5kg). No data exists regarding the golden langur’s lifespan.

Appearance
Slim and long-limbed, the golden langur gets her name from the gorgeous colors of her coat—a stunning golden-to-creamy white that reddens and darkens in the winter. As striking as her golden fur is, her black, nearly hairless face stands out as well, framed by a mane-like golden halo of hair. Researchers note that the golden langur in the south may have a more uniform coat than her cousin in the north and infants may be apricot-colored or orange-brown to gray when first born.

What Does It Mean?

Dipterocarp forest:
Prevalent in Asian tropical rainforests, trees of the family Dipterocarpaceae; regarded as economically valuable timber resources and, therefore, vulnerable to clearcutting.
 
Diurnal:
Active during daylight hours.

​Riverine:
Related to or situated near a river or riverbank.

Sacculated:
Having a series of different sections (e.g. langurs have sacculated stomachs, i.e. stomachs with three sections).

Visit the Glossary for more definitions

Diet
Langurs are also known as leaf monkeys—designed 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 north plains gray langurs, also called 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.

Daily Life and Group Dynamics 
Golden langurs appear to move in small groups of between two to 12 individuals, comprising one or two mature males and several females with offspring.

The research that has been conducted shows that golden langurs are diurnal, becoming most active during the early morning and afternoon for feeding as a group and pausing during the heat of midday for rest, social grooming, and play. Most of their time is spent navigating the canopy; they move quadrupedally (using all four limbs) to descend from trees, land, leap, or climb on large branches. By evening, the group will congregate in a sleeping tree for the night, although most adults do not appear to huddle for sleeping.

Fun Facts

Look what I found!
Gee’s golden langur was officially discovered in 1953 by Edward Pritchard Gee, a tea planter and amateur naturalist in Assam, India. The golden langur is named after Mr. Gee, although rumors of the elusive golden leaf eater’s existence had circulated for many years prior to Gee’s successful filming of the monkey, which provided indisputable proof of her existence.
 
What’s your name now?
​Since their discovery, golden langurs have had multiple scientific names. Today, they are classified as part of the Trachypithecus genus, but when they were first discovered, they were included in the genus Presbytis and later in the genus Semnopithecus. All three genus names fall under the subfamily Colobinae and the family Cercopithecidae.

Communication
While studies are still being conducted to understand the communication patterns between golden langurs, researchers are confident that these monkeys use vocalizations—alarm calls and screeches—to communicate. It’s also assumed by primatologists that golden langurs use other methods common to primates (including grooming, aggression, posturing, and facial expressions) to communicate.

Reproduction and Family
Golden langurs give birth to a single offspring after a gestation period of approximately six months. The mating season peaks in January and February, with births occurring in July or August; primatologists also note that mating and births can occur year-round. Males are thought to leave their natal group.

Information on parental care is limited, but researchers suggest that golden langurs may exhibit similar care patterns as Hanuman langurs, who leave the entirety of child-rearing to the mother and other females.

Photo credit: Doniv79/ Creative Commons

Ecological Role
Like most primates who eat fruits, golden langurs likely play a role in seed dispersal, seed predation, and pollination, all of which are critical for forest repopulation.

Conservation Status and Threats
While much research is needed on the Gee’s golden langur, one thing is clear: this species is at high risk. The International Union for Conservation of Nature designates the Gee’s golden langur as Endangered (IUCN, 2015) on its Red List of Threatened Species. In addition, the Gee’s golden langur is included in the International Primatological Society’s listing of the World’s 25 Most Endangered Primates in the 2016-2018 and 2018-2020 reports.

The number of mature individuals is estimated at 6,000-6,500. Population declines  over its entire range are suspected to be at more than 50% over the last three generations (36 years). It is further suspected that the rate of decline in India is well above 60%, definitely more than in Bhutan; but given the overall disturbance in both the countries due to increasing number of development projects, damming, conversion of forests for settlements, cultivation and plantations, the destruction of habitat is on the increase and is expected to continue into the future for another two decades at least at the same rate.

In February 2020, with the death of the lone male golden langur (Trachypithecus geei) that inhibited the Umananda (originally called Bhashmachal) Island in the middle of the Brahmaputra in Assam, the species has become extinct on the island.

Conservation Efforts
Although the outlook for the Gee’s golden langur is bleak, work is under way to help. Nearly all of the golden langur habitat in Bhutan falls in one of four different wildlife preserves and national parks set up for their protection (namely, the Royal Manas National Park, Black Mountain National Park, Trumsingla Wildlife Sanctuary, and Phipsoo Wildlife Sanctuary, which together provide sanctuary to more than half the golden langurs living today). In India, only two wildlife sanctuaries exist, protecting just a small area of habitat, but local residents and non-government organizations have been working to restore this langur’s habitat. One such project, the Golden Langur Conservation Project, saw some successes in mitigating illegal logging while others have worked to protect the golden langurs with a system of ropeways that have helped the monkeys cross a section of highway safely. 

Golden langurs are also named in India’s Wildlife Protection Act of 1972, while the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) includes the monkey on its Appendix I list of most endangered wildlife. 

References:

  • https://animaldiversity.org/accounts/Trachypithecus_geei/
  • http://www.arkive.org/golden-langur/trachypithecus-geei/
  • https://www.cambridge.org/core/journals/oryx/article/div-classtitlecommunity-protection-of-the-manas-biosphere-reserve-in-assam-india-and-the-endangered-golden-langur-span-classitalictrachypithecus-geeispandiv/32514F336B49C5D3A04688B8571AE468
  • http://www.communityconservation.org/Assam.htm
  • “Data on conservation research discussed by R.H. Horwich and colleagues.” Ecology, Environment & Conservation, 2 July 2010, p. 48. Global Issues In Context, http://link.galegroup.com/apps/doc/A229776806/GPS?u=mlin_c_stevens&sid=GPS&xid=67378b6f. Accessed 13 Apr. 2018.
  • Dinerstein, Eric. The Kingdom of Rarities. Washington, D.C.: Island Press, 2013. Print.
  • https://en.wikipedia.org/wiki/Edward_Pritchard_Gee
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  • 13 Apr. 2018.
  • http://www.iucnredlist.org/details/22037/0
  • “Ropeways to save langurs.” Telegraph [Calcutta, India], 8 Nov. 2012. Infotrac Newsstand, http://link.galegroup.com/apps/doc/A307861539/GPS?u=mlin_c_stevens&sid=GPS&xid=0c53daf6. Accessed 13 Apr. 2018.
  • http://www.sanctuaryasia.com/magazines/conservation/9716-kakoijana-home-of-the-golden-langurs/
  • “State Zoo to have golden langur conservation breeding facility.” Assam Tribune [Guwahati, India], 12 June 2011. Global Issues In Context, http://link.galegroup.com/apps/doc/A258692243/GPS?u=mlin_c_stevens&sid=GPS&xid=a73cae7e. Accessed 13 Apr. 2018.
  • http://www.theprimata.com/trachypithecus_geei/

Written by Christine Regan Davi, April 2018. Conservation status updated Dec 2020.