Black-faced spoonbills are spotted at a tidal flat in Zhoushan, Zhejiang province. [Photo/Zhejiang Daily]

Chen Bin, the leader of the Zhoushan Seaside Bird Survey Team, was surprised to find black-faced spoonbills recently at a tidal flat in Zhoushan, Zhejiang province, according to local media reports.

Chen noted that the birds have been wintering in Zhoushan for at least five consecutive years and the key to identifying them was one black-faced spoonbill labeled as "V73".

The black-faced spoonbill is referred to as "V73" because it wears a bird ring on its leg with the prominent marking "V73". Chen explained that birds wearing rings are known as ringed birds, and by monitoring these ringed birds, humans can understand the migration patterns, age, and population size of migratory birds.

Based on the characteristics, it can be determined that the bird ring of "V73" was placed by a South Korean organization.

Chen added that the birds come to Zhoushan in November each year and migrate northward in April of the following year, and the average lifespan of the black-faced spoonbill is 20 to 25 years.

The black-faced spoonbill breeds in the northern part of the Korean Peninsula and migrates south for winter. In China, it is generally a wintering bird, with stable wintering records in the provinces of Zhejiang, Fujian, Taiwan, and Guangdong.

Currently, there are only about 5,000 black-faced spoonbills worldwide. The black-faced spoonbill is listed as endangered (EN) on the IUCN Red List of Threatened Species and is a Class I protected animal in China.