Diversity and habitat associations of avifauna in the Poovar Estuary, Kerala, India

This study assessed bird diversity in Poovar, a coastal wetland complex in Thiruvananthapuram district, Kerala, India, from August 2024 to July 2025. 88 bird species from 17 orders and 37 families were documented, encompassing both resident and migratory populations. According to the IUCN Red List, all species were categorized as ‘Least Concern’ except for the River Tern Sterna aurantia and Oriental Darter Anhinga melanogaster, listed as ‘Vulnerable’ and ‘Near Threatened’, respectively. Based on migratory status, 56 species were residents and 32 were winter visitors, highlighting the role of Poovar as a significant refuge for migratory waterbirds along the southwest coast of India. Feeding guild analysis showed that 34% of species were insectivorous, followed by carnivores and piscivores, reflecting the functional diversity of the community. Habitat association indicated waterbirds utilized varied habitats, showing overlap in habitat-specific assemblages such as backwater, mangroves, and beaches, emphasizing the influence of habitat heterogeneity on avian distribution. Urban areas showed a distinctive species composition having little overlap with farmland assemblages. The habitat mosaic of Poovar supports a diverse and dynamic avifaunal assemblage. Habitat association analysis indicated that waterbirds utilized a variety of habitats.