The rising water level of Songhua River in Harbin City, northeast China's Heilongjiang Province, has led to a swarm of mayflies propagating there. 

The insects have attracted the attention of black-headed gulls, who fly back to the river after the breeding season.

In these pictures. thousands of black-headed gulls hover above the river and feast on a hearty meal of mayflies. 

(All images via CFP)

(If you want to contribute and have specific expertise, please contact us at nature@cgtn.com)