The degree of flexibility in choosing a nocturnal habitat is one of the most important factors in animal distribution and dispersion. From November 2015 to July 2018, we carried out a study on the nocturnal roosting site use and roosting tree selection of six Asian openbills (Anastomus oscitans) using satellite tracking technology in Mengzi Basin, Yunnan Province. Our results showed that (1) the Asian openbill used three habitats as nocturnal roosting sites, comprising woodlands, swamps, and small islands in lakes. At the population level, openbills mainly roosted in swamps (51.19%±12.34%), followed by woodlands (31.55%±11.34%) and islands (17.26%±5.70%). At the individual level, there were great differences in the utilization of nocturnal roosting sites between different individuals, of which four mainly roosted in the swamp, and the other two roosted in the woodland. (3) Random forest analysis showed that the primary factors influencing nocturnal roosting tree selection of openbills were distance to foraging site, followed by tree height, ground diameter, and lowest branch height. Asian openbills were not sensitive to human disturbance. In conclusion, the studied openbills exhibited strong adaptability and plasticity in their selection of nocturnal roosting habitats and roosting trees, which may be an important reason for their rapid range expansion. Our results also indicate that nocturnal roosting trees are not a significant limiting factor for the dispersal of Asian openbills; this bird may continue to spread to wetland areas in the south of China.