Douc Langurs (Pygathrix spp.) Fact Sheet: Population & Conservation Status

Pygathrix cinerea (gray-shanked douc langur)

• Population trend: decreasing
• Global population
  • Likely less than 2,000 individuals (Long et al. 2020)

Pygathrix nemaeus (red-shanked douc langur)

• Population trend: decreasing (Coudrat et al. 2020)
• Largest population likely in Nakai-Nam Theun National Park Area, Lao PDR (Coudrat et al. 2020)
  • At least 4,500 groups
• Other large populations in Vietnam (Coudrat et al. 2020)

Pygathrix nigripes (black-shanked douc langur)

• Population trend: decreasing (Duc et al. 2020)
• Largest populations in Cambodia (Seima Biodiversity Conservation Area): 42,000 individuals total (Pollard et al. 2007; Duc et al. 2020)
• Largest populations in Vietnam (Bu Gia Map National Park) approximately 1,800 individuals (Duc et al., in prep; Duc et al. 2020)

IUCN

• Pygathrix cinerea (grey-shanked douc langur): Critically Endangered (2015 assessment) (Long et al. 2020)
• Pygathrix nemaeus (red-shanked douc langur): Critically Endangered (2015 assessment) (Coudrat et al. 2020)
• Pygathrix nigripes (black-shanked douc langur): Critically Endangered (2015 assessment) (Duc et al. 2021)

CITES

• All species listed under Appendix I (UNEP 2019)

U.S. Endangered Species Act

• Pygathrix nemaeus: Endangered (U.S. Fish & Wildlife Service 2020)

Threats to survival (Lippold & Vu 1998)

• Vietnam has now lost over 80% of its historical forest cover. Only 10-20% of closed tropical forest remains.
• During the Vietnam War (1963-1975) over 72 million liters of herbicide were sprayed and approximately 22,000 sq acres of agricultural land and forests destroyed
• Rapid human population growth. More than 70 million people in 1990 - 80% of the population practices subsistence agriculture. Remaining forests are subject to commercial logging, hunting and clearance.
• Government policy of relocating landless northerners to central highlands is decimating forests and wildlife
• Large-scale logging operations in most of major forests
• Hunting for bush meat and medicinal purposes is a major activity. Many firearms in the country after years of warfare
• Illegal trade with China
• Subjects for taxidermy
• Protected wildlife is for sale in markets throughout the country
• Outside protected areas, remaining primate populations will become more fragmented

Conservation

• Vietnam Government inaugurated first national park at Cuc Phuong in 1962
• In 1986 additional national parks and reserves were established. Currently there are 87 areas totaling approximately 3% of Vietnam
• A National Conservation Strategy was prepared in 1985. The National Plan for Environment and Sustainable Development was created in 1991.
• At least 11 laws protect wildlife and CITES membership is in effect but law enforcement is weak, guards are underpaid, and punishments minimal (Without a set value on an endangered species it becomes impossible to set a fine for illegal hunting.)

Forest logging, hunting for bushmeat, and human population growth are causing drastic declines in douc langur populations.

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

MacKinnon and MacKinnon (1987)