Photographer Li Defu recently captured videos of a flock of 24 Chinese mergansers that had just arrived at Meirensong Lake in Yanbian Korean autonomous prefecture, Jilin province.

After spending approximately five hours on the lake, they flew away in three separate groups, according to Li.

Recognized as a national first-level protected animal and also classified as an endangered species on the red list of the International Union for Conservation of Nature, Chinese mergansers have been dubbed the "living fossils".

They usually choose ecologically superior and highly clean rivers, lakes, and wetlands as their habitats.

The appearance of such a large number of Chinese mergansers indirectly confirms the ongoing improvement of the regional ecological environment.

Video by Li Defu.