Foraging strategies and bioindicator potential of Black-winged Stilt (Himantopus himantopus) in an urban river ecosystem of Patna, Bihar, India

Urban wetlands and modified riverine systems are vital yet vulnerable habitats for waterbirds. This study explores the feeding ecology of Black-winged Stilt (Himantopus himantopus), a key bioindicator species, in a modified riverine wetland in Patna, India. A detailed observation on Black-winged Stilt (BWS) foraging behaviour was conducted across five sites during January–March 2025. We also assessed the microhabitat characteristics, water quality, and prey availability. The spatial and temporal variation in BWS abundance and feeding activity, prey selection, and their correlations with environmental parameters (nutrient concentration and water depth) and the impact of human disturbance was investigated. BWS showed a strong preference for shallow (5–10 cm), highly eutrophic sites (nitrate = 3.25±0.14 mg/L, phosphate = 2.63±0.16 mg/L), which correlated with high densities of Chironomus larvae, Tubifex and Moina. Pecking was the dominant foraging technique (72%), with activity peaking in the early morning. These findings highlight the BWS’s adaptability and bioindicator potential in urban environments. Conservation efforts should prioritize maintaining critical microhabitats, regulating disturbances, and promoting community engagement for sustainable avifaunal conservation.