Diversity dynamics of waterbirds along the bird migration flyways: Insights from lotic and lentic wetlands in eastern India

Abstract Wetlands in Paschim Bardhaman, West Bengal, India, represent vital habitats for migratory and resident waterbirds along the East Asian–Australasian and Central Asian Flyways. This study assessed waterbird diversity across 11 lotic and lentic wetlands from 2020 to 2025, analysing species richness, abundance, and diversity indices. Using modified total count methods, 78 species were recorded, with Durgapur Barrage and Burnpur Riverside showing the highest abundance and richness, respectively. Alpha-diversity indices revealed significant site-level variations, while beta-diversity analyses highlighted distinct species compositions, particularly at species-poor sites like Nachan Dam. Cluster analysis grouped sites based on species abundance, revealing both ecological similarity and distinctiveness. The widespread dominance of Lesser Whistling-Duck and localized records of rare species such as Falcated Duck and Common Merganser underscore the conservation significance of both high- and low-diversity wetlands. The findings stress the importance of a landscape-scale conservation strategy integrating habitat heterogeneity, anthropogenic impacts, and flyway connectivity. Long-term monitoring and habitat-specific management are essential to ensure the ecological integrity of these transitional wetlands during rapid urban and industrial expansion.