Each spring, the banks of the Mengboluo River in Yunnan province become a busy habitat for the industrious baya weaver. This agile creature, famous for its intricately woven bag nests, flocks here in search of suitable branches on mango trees, flame trees and bamboo clumps.

Along a roughly 25-kilometer stretch of the river winding through Wandian Dai township in Baoshan city, nearly 2,000 birds arrive each breeding season, drawn by the warm, humid climate and plentiful trees that make this reach an ideal breeding ground, according to the local environmental protection bureau.

Building a single nest is no small undertaking. Within 20 to 25 days, a male bird weaves thousands of grass stems into a sturdy pouch and hangs it from a branch. This structure is both his workshop and his showcase — a flawless nest increases the chances of attracting a mate.

Courtship hinges on craftsmanship. A visiting female bird inspects the nearly completed nest and either approves or rejects it. Only after a female's nod does the male finish his nest.