Every March, grey herons return to Kangle county in Linxia Hui autonomous prefecture, Gansu province, where they nest among the ancient trees. This annual event has become a symbol of Kangle's ecological beauty and balance.

For over 60 years, the number of herons in Kangle has grown from just a few to thriving groups. This reflects the county's successful efforts to foster environmental preservation and highlights the harmonious coexistence between humans and nature.