First Grassland Bird Census in Kaziranga

In a recent episode of the "Mann ki Baat" radio program on July 27, 2023, Prime Minister Narendra Modi discussed the inaugural grassland bird census conducted in Kaziranga National Park, Assam. This survey, which ran from March 18 to May 25, aimed to assess the population of grassland birds in a park where 70% of the landscape comprises grasslands.

Key Highlights:

• Initiation of the Census: The project began when Chiranjib Bora, a doctoral student studying the threatened Black-breasted Parrotbill, received an INSPIRE fellowship from the Department of Science & Technology. Equipped with acoustic monitoring tools, he collaborated with Kaziranga officials for the census.

• Objectives: The main aim was to document the species of grassland birds, which are often rare, small, and well-camouflaged, making them difficult to count using traditional visual methods. The survey focused on 10 species that are globally threatened or endemic to the Brahmaputra floodplains, including:

  • Bengal Florican
  • Swamp Francolin
  • Finn’s Weaver
  • Swamp Grass Babbler
  • Jerdon’s Babbler
  • Slender-billed Babbler
  • Black-breasted Parrotbill
  • Marsh Babbler
  • Bristled Grassbird
  • Indian Grassbird

• Surveillance Methodology: This survey employed a unique methodology involving passive acoustic recording. Acoustic recorders were strategically placed in tall trees near grasslands during the breeding season (March-May) to capture the vocalizations of the birds, which are more active during this time.

  • After gathering data over three days, the recordings were analyzed. Various tools were used, including software for sound spectrograms and the Birdnet tool, which utilizes machine learning for bird song identification. The survey covered 29 locations within the national park using six recorders.

• Findings: The study documented a total of 43 grassland bird species, which included:

  • 1 Critically Endangered species
  • 2 Endangered species
  • 6 Vulnerable species (according to the IUCN Red List).

  Notably, a breeding colony of the endangered Finn’s Weaver was discovered, containing over 85 nests, marking a significant ecological finding.

• Ecosystem Significance: According to Dr. Sonali Ghosh, Director of Kaziranga National Park, grassland birds serve as indicators of ecosystem health, similar to how Body Mass Index (BMI) reflects human health. The presence of these birds suggests a healthy habitat, though numerous threats pose risks to their existence.

Threats to Grassland Birds:

• Habitat Loss: Assam has lost approximately 70% of its grasslands over the past four decades due to:

  • Overgrazing
  • Agricultural encroachment
  • Natural ecological succession leading to forestation.

• Climate Change: The impacts of climate change are also concerning. For instance, observations of the Bengal Florican showed a drastic population decline compared to past surveys, prompting further research on the cause of such declines.

Conclusion:

The first-ever grassland bird census in Kaziranga National Park highlights the urgent need for conservation efforts for grassland birds and their habitats. The census not only provides critical data for understanding current avian populations but also emphasizes the significant ecological challenges they face.

Important Points:

• The grassland bird census took place in Kaziranga National Park from March 18 to May 25, 2023.
• 43 grassland bird species were documented, including several threatened ones.
• Unique acoustic monitoring techniques were employed for data collection.
• Significant threats to bird populations include habitat destruction and climate change.
• Grassland birds are crucial indicators of ecosystem health.