Phayre’s Langur and Western Hoolock Gibbon

Source:  DTE

Context: The ‘Primates in Peril 2023–2025’ report has listed Cross River Gorilla and Tapanuli Orangutan among the 25 most endangered primates globally.

• Two Indian species — Phayre’s Langur and Western Hoolock Gibbon — were considered for the final list, highlighting their growing conservation concern.

About Primates in Peril 2023–2025:

What It Is?

• A biennial global report identifying the 25 most endangered primates worldwide based on scientific assessments.

Published By:

• An international team of primatologists, supported by institutions like IUCN, Bristol Zoological Society, and Conservation International.

Global Distribution of Threatened Species

• Africa: 6 species
• Asia: 9 species
• Madagascar: 4 species
• Neotropics (South America): 6 species
• 15 primates are newly added. (Of them 8 features for the first time).

About Phayre’s Langur (Trachypithecus phayrei):

• Status:

• • IUCN Red List: Endangered
  • Distribution: Northeast India, East Bangladesh, and Western Myanmar
  • Habitat: Tropical evergreen, deciduous, and bamboo-dominated forests

• Features:

• • Physical:
    • Deep bluish-brown coat, spectacle-like white rings around eyes
    • Males weigh ~7.9 kg; females ~6.9 kg
    • Tail longer than body, aiding arboreal movement
  • Biological & Social:
    • Lives in arboreal groups, mainly diurnal and folivorous.
    • Distinct sagittal crest on head; vocal and territorial behavior.
  • Diet:
    • Primarily leaf-eating (colobine); also consume fruits and seeds
    • Shows specialized craniodental adaptations for seed consumption.

About Western Hoolock Gibbon (Hoolock hoolock):

• Status

• • IUCN Red List: Endangered
  • WPA: Schedule I
  • CITES: Appendix II
  • Distribution: Northeast India, Eastern Bangladesh, Western Myanmar
  • Habitat: Tropical evergreen and semi-evergreen forests

• Features:

• • Physical:
    • Males are black with white brows, females are grey-brown
    • Known for vocal duets and white rings around eyes and mouth
  • Biological & Social:
    • Lives in monogamous pairs with strong territorial behavior
    • Moves by brachiation at speeds up to 55 km/hr
  • Diet:
    • Primarily frugivorous, supplemented by insects and leaves
    • Arboreal and diurnal, relying heavily on tall canopy cover