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

Douc Langurs (Pygathrix spp.)

Population Status

Pygathrix cinerea (gray-shanked douc langur)

  • Population trend: decreasing
  • Total population
    • Less than 1,000 individuals (Nadler and Roos 2013)
  • Ngoc Thanh (2008a): "The total population for this species is estimated at 550 to 700 individuals, but some areas with assumed occurrence are not yet surveyed (Ha Thang Long 2004)."

Pygathrix nemaeus (red-shanked douc langur)

  • Population trend: decreasing (Ngoc Thanh 2008b)
  • Believed to have undergone more than a 50% decline since 1980 (Ngoc Thanh 2008b)
  • Largest population in Phong Nha-Ke Bang National Park (Nadler and Roos 2013)
    • Approximately 1,500 individuals

Pygathrix nigripes (black-shanked douc langur) (Rawson et al. 2008)

  • Population trend: decreasing
  • Believed to have undergone more than a 50% decline since 1980
  • Largest populations in Cambodia (42,000); an estimated 600-800 in Vietnam, but in small, isolated forest fragments

Conservation Status

IUCN

  • Pygathrix cinerea (grey-shanked douc langur): Critically Endangered (2008 assessment) (Ngoc Thanh 2008a)
  • Pygathrix nemaeus (red-shanked douc langur): Endangered (2008 assessment) (Ngoc Thanh 2008b)
  • Pygathrix nigripes (black-shanked douc langur: Endangered (2008 assessment) (Rawson et al. 2008)

CITES

  • All species listed under Appendix I (UNEP 2019)

U.S. Endangered Species Act

Threats to Survival

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

Management Actions

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.)

Threats to Langurs

Red-shanked douc langur

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

Image credit: © San Diego Zoo Global. All rights reserved.

Page Citations

MacKinnon and MacKinnon (1987)

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