Kaziranga Grassland Avifauna Survey

A first-of-its-kind survey (March–May 2025) documented 43 grassland-dependent bird species in Kaziranga National Park, underscoring its critical role as a grassland biodiversity hotspot in the Brahmaputra floodplains.

Location & Geography

• Located in Assam, along the Brahmaputra River between Brahmaputra floodplains and the Karbi (Mikir) Hills.
• Traversed by Diphlu River and National Highway 37.
• Part of the Eastern Himalayan Biodiversity Hotspot.

Prominent Fauna

• "Big Five" mammals: Great Indian One-Horned Rhino, Royal Bengal Tiger, Asiatic Elephant, Asiatic Water Buffalo and Swamp Deer
• Others: Sloth Bear, Hog Deer, Sambar, Panther, Gaur, Capped Langur, Hoolock Gibbon.
• Aquatic: Gangetic River Dolphin in oxbow lakes.
• Avifauna: Migratory and resident birds from Australasia and Indo-Asian Flyways.
  • Eg: Baer’s Pochard, Greater/Lesser Adjutant, Ferruginous Duck, Asian Openbill.

Vegetation and Ecosystem

• • Dominated by Wet Alluvial Tall Grasslands (~2/3rd area).
  • Interspersed with Tropical Moist Deciduous and Semi-Evergreen Forests.
  • Known for Elephant Grasses, swamplands, and seasonal wetlands.

Avian Biodiversity Documentation in Kaziranga:

• A total of 43 grassland bird species were documented across Kaziranga’s three wildlife divisions, using field observation and passive acoustic monitoring.
• Notable species recorded include:
  • Critically Endangered: Bengal Florican
  • Endangered: Finn’s Weaver, Swamp Grass Babbler
  • Vulnerable (6 species): Black-breasted Parrotbill, Marsh Babbler, Swamp Francolin, Jerdon’s Babbler, Slender-billed Babbler, Bristled Grassbird
• The presence of Finn’s Weaver breeding activity is a key indicator of healthy wet grassland ecosystems.

Ecological and Conservation Significance:

• The wet grasslands of Kaziranga are ecologically rich but have remained under-surveyed in India compared to dry grasslands in Gujarat and Rajasthan.
• Kaziranga’s ecosystem is a mosaic of grasslands, forests, and wetlands spread across 1,174 sq. km in the floodplains of the Brahmaputra.
• Grassland birds are often habitat-specific and cryptic, making this systematic monitoring vital for long-term conservation efforts.

Technological Innovation in Wildlife Monitoring:

• Passive acoustic recorders were used for the first time in Kaziranga for avian research.
• This non-invasive method enabled continuous species monitoring in inaccessible or high-risk areas, improving detection accuracy for elusive bird species.
• The study sets a scientific precedent for future biodiversity assessments in wet grassland habitats across India.