What is the Black-Shanked Douc Langur?
The Black-Shanked Douc Langur (Pygathrix nigripes)
is a striking and elusive species of Old World monkey belonging to the
Colobinae subfamily—commonly referred to as leaf-eating monkeys. Recognized for
its vibrant facial features and glossy black limbs, the Black-Shanked Douc is
one of three douc langur species, the others being the red-shanked and
grey-shanked doucs.
This primate is primarily arboreal (tree-dwelling)
and diurnal (active during the day), living in the high canopy of
tropical and subtropical forests. Its diet consists mainly of leaves, but it
also consumes fruits, seeds, and flowers, playing a vital role in forest
ecology.
Where Does the Black-Shanked Douc Langur Come From?
In terms of evolutionary origin and habitat, the
Black-Shanked Douc Langur is endemic to Southeast Asia, specifically
parts of Cambodia and Vietnam. It is a species that evolved in
the tropical forests of the Indochina region, developing unique
adaptations for life in the forest canopy.
Where is the Black-Shanked Douc Langur Found?
The Black-Shanked Douc Langur is found in:
- Eastern
Cambodia, especially in Mondulkiri and Kratié Provinces
- Southern
and southeastern Vietnam, notably in provinces like Đồng Nai, Lâm
Đồng, and Bình Phước
Its habitat ranges include evergreen, semi-evergreen, and
deciduous forests, typically in hilly or mountainous terrain. The species
requires large tracts of forest with continuous canopy cover to thrive.
Where is the Black-Shanked Douc Langur Most Abundant?
The largest and most stable population of Black-Shanked Douc
Langurs exists in eastern Cambodia, particularly within the Seima
Biodiversity Conservation Area (SBCA) in Mondulkiri Province.
A comprehensive survey conducted in 2007 estimated that over
42,000 individuals resided in the SBCA alone—representing the largest
known population of any douc langur species. By contrast, populations in
Vietnam are significantly smaller and more fragmented due to habitat loss and
hunting.
Who First Discovered the Black-Shanked Douc Langur?
The Black-Shanked Douc Langur was first described in
scientific literature by Alphonse Milne-Edwards, a French zoologist, in 1871.
He initially classified it under the genus Semnopithecus based on
specimens collected near Saigon (now Ho Chi Minh City), Vietnam. It was
later reassigned to the genus Pygathrix as part of taxonomic revisions
based on its close relationship to other douc langurs.
What is the Significance of the Black-Shanked Douc Langur
on Earth?
The Black-Shanked Douc Langur is ecologically,
scientifically, and culturally significant:
- Ecological
Role: As a folivore, it aids in seed dispersal and maintaining forest
health. Its feeding habits help shape vegetation patterns in tropical
forests.
- Biodiversity
Indicator: Its presence signals healthy, undisturbed forest
ecosystems, making it a key species for monitoring habitat integrity.
- Flagship
Species: Due to its distinctive appearance and endangered status, it
is a conservation flagship for Southeast Asian forest biodiversity.
- Cultural
Importance: In local folklore and regional conservation efforts, doucs
symbolize the beauty and fragility of tropical forests.
Who Named the Black-Shanked Douc Langur?
The species was scientifically named by Alphonse
Milne-Edwards in 1871. The species name "nigripes" is
derived from Latin, meaning "black-footed"—a direct reference to its
distinctive black lower limbs. Over time, the species was moved to the genus Pygathrix,
which was originally defined by Étienne Geoffroy Saint-Hilaire in the early
19th century for douc monkeys.
How Many Black-Shanked Douc Langurs Are There on Earth?
Population estimates are challenging due to the species’
elusive nature and the remoteness of its habitat. However:
- In Cambodia,
the Seima Biodiversity Conservation Area alone is estimated to support more
than 42,000 individuals (as of a 2007 survey).
- In Vietnam,
fragmented populations persist, with the largest known groups containing between
500 to 700 individuals in specific protected areas such as Cát Tiên
National Park and Bạch Mã National Park.
Taking these figures into account, the total global
population is likely to range between 45,000 and 50,000 individuals, though
accurate, updated surveys are needed to confirm these estimates.
Summary: Where is the Black-Shanked Douc Langur Most
Abundant?
- The most
abundant and stable population of the Black-Shanked Douc Langur is
found in eastern Cambodia, particularly in the Seima
Biodiversity Conservation Area, Mondulkiri Province.
- Vietnam
hosts much smaller, more fragmented populations due to
extensive habitat loss and hunting pressure.
Conclusion
The Black-Shanked Douc Langur is one of Southeast
Asia’s most unique and endangered primates. While it enjoys relative abundance
in parts of Cambodia, its future remains uncertain due to habitat destruction,
hunting, and limited conservation enforcement—especially in Vietnam. Its continued
survival will depend on sustained conservation efforts, habitat protection, and
transboundary cooperation between Vietnam and Cambodia.
✅ Sources of Reference
- IUCN
Red List of Threatened Species
➤ Pygathrix nigripes assessment
Link: https://www.iucnredlist.org/species/39856/17922526 - New
England Primate Conservancy (NEPC) – Douc Langur Species Profiles
Link: https://neprimateconservancy.org/douc-langurs/ - WWF
Cambodia – Wildlife at Risk: Black-Shanked Douc Langur
Link: https://www.wwf.org.kh/our_work/wildlife_at_risk_in_cambodia/mammals/black_shanked_douc/ - ScienceDaily
– “World’s Largest Population of Globally Endangered Primate Discovered in
Cambodia”
Article on Seima Biodiversity Conservation Area
Link: https://www.sciencedaily.com/releases/2008/08/080828120326.htm - Ecology
Asia – Black-Shanked Douc Langur (Pygathrix nigripes)
Link: https://www.ecologyasia.com/verts/mammals/black-shanked-douc.htm - Mammal
Diversity Database (MDD) – American Society of Mammalogists
Entry for Pygathrix nigripes
Link: https://www.mammaldiversity.org/taxa.html - Fauna
& Flora International (FFI) – Cambodia and Vietnam primate
conservation efforts
Link: https://www.fauna-flora.org - Vietnam
Primate Conservation Program (VPCP)
Regional studies on douc langurs in Vietnam
Link: https://www.primate-sg.org/vietnam/
