Importance of conserving a critical wintering ground for shorebirds in the Valinokkam Lagoon—a first study of the avifaunal distribution of the southeastern coast of India

Abstract

Any new economic activity in a virgin area brings landscape changes, making it essential to document baseline biodiversity areas to understand the impacts on habitats. Avifaunal inventories are critical for previously undocumented areas, especially in a wintering site for shorebirds in the Central Asian Flyway, to formulate site- and species-specific conservation management tools. We present an annotated checklist of avifauna from the Valinokkam Lagoon in the Ramanathapuram district of Tamil Nadu. We recorded the first baseline avifaunal data for 154 species belonging to 16 orders and 46 families from August 2016 to February 2023. Order-wise, Charadriiformes dominated the study site with 47 species; followed by Passeriformes with 39 species and Pelecaniformes with 20 species. Winter visitors constituted 37.6 % (58 species) and one Passage Migrant Rosy Starling Pastor roseus. The relative abundance indicated that 94 species were C (common), 41 species were UC (uncommon), and 19 species were Ra (rare). Eleven Near Threatened (NT) species:  Oriental Darter Anhinga melanogaster, Painted Stork Mycteria leucocephala, Black-headed Ibis Threskiornis melanocephalus, Spot-billed Pelican Pelecanus philippensis, Black-tailed Godwit Limosa limosa, Bar-tailed Godwit Limosa lapponica, Great Stone-curlew Esacus recurvirostris, Eurasian Curlew Numenius arquata, Curlew Sandpiper Calidris ferruginea, Red-necked Stint Calidris ruficollis and Red Knot  Calidris canutus, one Endangered (EN) species Great Knot Calidris tenuirostris, and one unassessed Hanuman Plover Charadrius seebohmi according to the IUCN Red List category. This baseline data highlights the importance of Valinokkam Lagoon as an important wintering site in the Central Asian Flyway on the southeast coast of India for migratory shorebirds and the need for more conservation priorities for regional endemic birds like Hanuman Plover.