Is the Asian Openbill Migratory? Population Status and Habitat Use in Eastern Nepal

ABSTRACT The Asian Openbill ( Anastomus oscitans ) is a colonial waterbird found across South and Southeast Asia. Despite its overall stable population status globally, it faces vulnerability in Nepal, mainly due to unplanned urbanization across farmlands, agrochemicals, and wetland encroachment. We assessed the population status through direct counts and analyzed habitat use using generalized linear mixed modeling across five districts of eastern Nepal (2020–2022). We found that the Asian Openbill predominantly roosted near waterbodies and frequently utilized farmland habitats. The population count of the species was significantly higher during the breeding season compared to nonbreeding season. Farmland and wetland areas had positive influence on the species' habitat use. Our findings suggest that the Asian Openbill migrates seasonally, likely from northern India, with large numbers arriving in eastern Nepal to breed, while a few remain resident year‐round. These findings underscore the need for effective management of farmland and wetland landscapes for their conservation.