Context: 

The Standing Committee of the National Board for Wildlife (NBWL) has approved an oil and gas exploration project in the eco-sensitive zone (ESZ) of the Hollongapar Gibbon Wildlife Sanctuary in Assam.

About the Oil and Gas Exploration Project

• An oil exploration company has proposed exploratory drilling in the eco-sensitive zone (ESZ) of the Hollongapar Gibbon Wildlife Sanctuary in Assam.

• The drilling is for exploring potential hydrocarbon reserves in the area, based on seismic mapping results.

• The company assured that no hazardous substances will be used, and drilling will be for exploratory purposes only.

• The drilling site is located 13 km from the Hollongapar Gibbon Wildlife Sanctuary, which is home to the endangered Hoolock gibbon and six other primate species found in the area.

• While the sanctuary itself covers 20.98 square kilometres, its ESZ extends over 264.92 square kilometres. The large ESZ ensures connectivity with adjacent forested areas in Assam and Nagaland. 

• While granting the approval, the Standing Committee of NBWL has imposed several conditions – 

• Real-time digital surveillance systems to monitor operations.
• Detailed operational plans must be submitted to regulatory bodies before starting work.
• Minimal tree felling and strict pollution control measures.
• Oil or gas extraction is strictly prohibited within the ESZ, even if reserves are found. 

Hollongapar Gibbon Wildlife Sanctuary

• Located in the Jorhat district of Assam, it is named after India’s only ape species, the Hoolock gibbon, and became a wildlife sanctuary in 1997. 
• The Bhogdoi River creates a waterlogged area with semi-hydrophytic plants along the border.
• The upper forest canopy is dominated by Hollong trees, and the middle canopy has Nahar trees.

About the Hoolock Gibbon Species:

• Gibbons are the smallest and fastest apes, living in tropical and subtropical forests of Southeast Asia. 
• They are known for their intelligence, unique personalities, and strong family bonds, similar to other apes. There are 20 different species of gibbons worldwide.

• Population and Habitat: There are about 12,000 hoolock gibbons today. 

• They live in forests in Northeast India, Bangladesh, Myanmar, and Southern China.

• Gibbon Species in India: The hoolock gibbon is the only ape species in India. India is home to two subspecies of hoolock gibbons: 

• the eastern hoolock gibbon (Hoolock leuconedys) and 
• the western hoolock gibbon (Hoolock hoolock), mainly in the northeastern part of the country. 

• Conservation Status: According to the International Union for Conservation of Nature (IUCN) Red List:

• Western hoolock gibbon is listed as Endangered.
• Eastern hoolock gibbon is listed as Vulnerable.
• Both species are protected under Schedule 1 of the Indian Wildlife Protection Act 1972.

• A study by the Centre for Cellular and Molecular Biology (CCMB) in Hyderabad found that these are not two separate species. 

• Instead, they are part of the same species, with the two populations splitting about 1.48 million years ago. 
• The study also shows that all gibbons shared a common ancestor about 8.38 million years ago.