Status, Diversity and Species Composition of Wetland Birds on Vaduvoor Bird Sanctuary, Tiruvarur District, Tamil Nadu, India

Birds serve as the best indicators of wetland function and as measures of success in wetland management, restoration, and creation. This study was conducted from 2022 to 2024 in the Vaduvoor Bird Sanctuary of Tiruvarur district, employing the total count method to estimate the population of wetland birds. Year-wise species diversity, richness, relative diversity, evenness, density, and relative abundance were calculated. A total of 147 bird species belonging to 48 families and 18 orders were recorded. The maximum diversity and evenness were observed in 2024 (3.05 and 0.37), while the minimum values were recorded in 2023 (2.11 and 0.21). The total density was highest in 2023 (162.68/ha) and lowest in 2024 (27.82/ha), and species richness peaked in 2022 (117) and was lowest in 2024 (84). This sanctuary complex supports three IUCN Red-listed, four Near Threatened species: Curlew Sandpiper (Calidris ferruginea), Spot-billed Pelican (Pelecanus philippensis), Black-headed Ibis (Threskiornis melanosephalus), and Oriental Darter (Anhinga melanogaster), two vulnerable species: Yellow-throated Bulbul (Pycnonotus xantholaemus) and River Tern (Sterna hirundo), and one Endangered species – Lesser Sand Plover (Charadrius mongolus). This paper provides an overview of the current status and the IUCN status of wetland birds within the study area.