Assam bird sanctuary records 72% decline in bird species count

Sub: Env

Sec: Protected Area

Context:

A recent study published in the Journal of Threatened Taxa revealed a drastic 72% decline in avian species over 27 years at the Bordoibam Bilmukh Bird Sanctuary (BBBS) in Assam.

Details of the study:

Researchers conducted a survey from October 2022 to March 2024, recording 47 bird species compared to 167 species in 1997.
Out of all the species recorded, three – brown shrike, citrine wagtail, and white wagtail – were winter migratory while the lesser kestrel was a summer migratory and the remaining 43 were resident species.

Causes for decline in Avian Diversity:

Overfishing and excessive harvesting of aquatic plants
Poaching of birds and collecting bird eggs: Among the birds poached are the lesser whistling duck, fulvous whistling duck, white breasted waterhen, Indian pond heron, eastern spot ted dove, and yellow-footed green pigeon.
High-decibel machinery used for crop cultivation near water bodies.
Conversion of sanctuary areas into pastures.

Degradation of the wetland habitat leads to:

Biodiversity of Assam:

Assam is one of the most biodiversity-rich states in India, home to approximately 950 bird species, including 17 endemic species.
The state has 55 Important Bird and Biodiversity Areas (IBAs) that serve as hotspots for avian species.

Bordoibam Bilmukh Bird Sanctuary (BBBS):

Bordoibam-Bilmukh is a large freshwater lake that was created during the great earthquake of 1950. It was part of the River Subansiri, which now flows 7 km away
It is a wetland sanctuary located on the border of Dhemaji and Lakhimpur districts in Assam, established in 1996.
It encompasses approximately 11.25 square kilometers of freshwater ecosystems.
A large number of migratory waterfowl are seen here in winter while some globally threatened species such as the Spot-billed Pelican Pelecanus philippensis and Lesser Adjutant Leptoptilos javanicus are seen all over the year.