The latest survey reveals the population estimation of golden langurs in India conducted by various organizations.
Survey Methodology
The survey was conducted in two phases using the block count method.
Phase One (March-April 2020)
- Covered the western part of the Manas Biosphere Reserve.
- Included Ripu Reserved Forest, Chirang Reserve Forest, Manas Reserve Forest, and Manas National Park.
Phase Two (March-April 2021)
- Focused on fragmented forest habitats in Bongaigaon, Kokrajhar, and Dhubri districts of western Assam.
- Employed the block count method to assess abundance, spatial distribution, and densities.
Survey Results
- Total Population: 7,396 individuals in 707 groups, inclusive of bisexual and male bands, along with 31 lone males.
- Sub-populations:
- Northern Extended Population: 5,566 individuals in 534 groups and 23 lone males.
- Southern Fragmented Population: 1,830 individuals in 173 groups and eight lone males.
Habitat Distribution
- Northern population: Encompasses the western part of the Manas Biosphere Reserve.
- Southern fragmented population: Along the southern side of NH27 up to the Brahmaputra River.
Habitat Highlights
- Northern Population: Most found in Ripu Reserve Forest (2,847 individuals).
- Southern Fragmented Range: Highest population in Chakrashila Wildlife Sanctuary, Kokrajhar district (838 individuals).
Population Trends
- Previous estimation (2008-09): Recorded 6,000 golden langurs in India.
- Average group size: Increased in the latest survey compared to the previous one.
Conservation Concerns
- Unstable situation in fragmented habitats, particularly due to the absence of non-breeding all-male bands.
- Highlighted the need for corridor linkage among fragmented habitats through plantations and canopy bridges to offset potential threats from anthropogenic interactions.
Multiple Choice Questions (MCQs):
- Who conducted the latest survey on golden langurs in India?
- A) Assam Wildlife Department
- B) Primate Research Centre NE India (PRCNE)
- C) Indian Forest Service
- D) Indian Institute of Science
- What was the methodology used in the second phase of the survey?
- A) Aerial survey
- B) Block count method
- C) Camera trapping
- D) Transect sampling
- Where was the highest population of golden langurs found in the northern population?
- A) Chakrashila Wildlife Sanctuary
- B) Ripu Reserve Forest
- C) Manas National Park
- D) Bongaigaon district
- What was the estimated population of golden langurs in the southern fragmented population?
- A) 534 individuals
- B) 1,830 individuals
- C) 7,396 individuals
- D) 838 individuals
- What conservation concern was highlighted in the survey report?
- A) Decline in average group size
- B) Presence of stable habitats
- C) Presence of non-breeding all-male bands
- D) Lack of corridor linkage among fragmented habitats