Qinghai Lake, China's largest inland saltwater lake, has seen an increasing number of water birds, with some starting to breed, the local nature reserve's administration said.

Based on a five-day bird monitoring operation starting last week, the monitoring staff observed 42 species of water birds totaling over 44,000 in number, 8,000 more than the same period in 2021, said He Yubang, head of the administration.

The observed birds included 88 state first-class protected black-necked cranes, 16 state second-class protected podiceps nigricollis and six whooper swans.

He said water birds have entered breeding season.

The latest data shows that the water area of Qinghai Lake reached 4,625 square km, an increase of nearly 220 square km compared with a decade ago, He noted.

Qinghai Lake is an important ecological barrier in northern China and a key stopover site for migrant birds.