Temporal dynamics of shorebird assemblages in Valinokkam Lagoon, Southeast India: A new wintering site along the Central Asian Flyway

Anthropogenic activities are global threats to natural coastal wetlands that are crucial for shorebirds. Man-made wetlands such as salt extraction ponds provide alternate sites for feeding and roosting. Valinokkam Lagoon, a salt extraction site on the southeast coast of India, has emerged as a critical wintering and over-summering site along the Central Asian Flyway. A five-year study (2019 to 2024) documented 32 shorebird species, which include eight Near Threatened, two Vulnerable, two Endangered, and a single regional endemic Hanuman Plover, unassessed (IUCN). 87.5% of the species were winter visitors and four were breeding residents. Eleven species of over-summering shorebirds were documented, highlighting consistent resources in the lagoon throughout the year. Temporal abundance patterns peaked in 2023–2024, with the highest total monthly abundance in January 2023. Little Stint, Siberian Sand Plover, Curlew Sandpiper, and Kentish Plover were the dominant species. The highest species richness and diversity were in 2021–2022, and lowest in 2023–2024. This is the first pivotal study from this unprotected lagoon, which acts as a substitute for natural wetlands. This study further contributes to the estimation of global population trends, and hence this site requires further conservation action plans both regionally and internationally, as 72% of the species recorded here show a declining global trend.