More than 300 migratory whooper swans arrived at Manas National Wetland Park during the Spring Festival holiday from January 31 to February 6. Researchers identified one returning guest among the flock - a banded whooper swan with the serial number "1T11." Bird banding is a common practice for studying and identifying individual birds. Band number "1T11" has been spotted for nine consecutive years in the wetland in northwest China's Xinjiang Uygur Autonomous Region.