In Changning County, southwest China's Yunnan Province, over 3,000 pairs of blue-tailed bee-eaters have entered their nesting and chick-rearing season. On a sand cliff, thousands of tunnel-like nests, carefully carved with their beaks and claws, dot the surface. These stunning birds, listed as a Class II protected species in China, are known for their vibrant feathers. Often called "China's most beautiful bird," they migrate each summer from Southeast Asia to the Nujiang River region, turning cliff walls into a spectacular avian nursery of nearly 10,000 individuals.