A black-billed gull flies around Haimen district in Nantong, East China's Jiangsu province. [Photo/ntfabu.com]

Black-billed gulls have been seen among waterbirds wintering in Haimen district in Nantong, East China's Jiangsu province, the Nantong ecology and environment bureau announced on Feb 17.

The appearance of black-billed gulls, a bird species under first-class national protection, indicates that the district's ecological environment has improved significantly, said a local official.

Endangered species such as cygnets, Ruddy turnstone, Eurasian Curlew and Estern Curlew were also recorded in the district.

Haimen has in recent years been making efforts to conduct biodiversity surveys and assessment that have identified 65 bird species, including a wild animal under first-class national protection, six wild animals under second-class national protection, and eight species listed among IUCN (International Union for Conservation of Nature) Red List of Endangered Species.

As one of the important stops of the plover-migration routes in East Asia, Haimen will sustain efforts to strengthen the conservation of its abundant wetland resources that provide ideal habitats for migrant birds, said local authorities.