The Baya Weaver (Ploceus philippinus) is a sparrow-sized songbird known for weaving hanging nests from grass and leaves. Found across the Indian subcontinent and much of Southeast Asia, it flocks in open grasslands, farmlands, and scrubby areas near water, where its woven nests dangle from thorny trees to stay out of reach of predators. During breeding season, males sport bright yellow plumage on their heads.

Using long, fibrous strips torn from grasses and palm fronds (each measuring 20 to 60 centimeters), the male weaver may make up to 500 trips to gather materials and knit them together with his beak. He loops the fibers around a branch to anchor the structure, then builds a basket-like “helmet” that will become the upper part of the nest.

At this helmet stage, the male begins his courtship display. He hangs upside down, fluttering his wings and chirping to attract a female. Prospective mates fly by like discerning homebuyers, inspecting the structure's quality and placement. If one approves, she enters and helps line the interior with soft grass or feathers, and the male completes the narrow tunnel entrance. If none are impressed, he may tear the nest down and start again. One researcher counted more than 3,400 woven grass strips in a single nest.

All of this craftsmanship serves a single purpose: to secure a mate. The female will only choose a male if his nest meets her standards. Only then is the structure completed and ready for eggs.

Baya Weavers are social birds that prefer nesting in colonies. It's common to see dozens of their hanging nests clustered on a single tree. Most colonies consist of 20 to 30 nests, but some have far more; in one case, over 200 nests covered the branches of a single tree.

Males choose their nesting spots carefully. Nests are typically suspended from tall palms or thorny acacia trees, often over water. This location offers security. Predators like cats and snakes are discouraged by thorny branches, and few are willing to risk climbing over water. The farther a nest is from solid ground, the safer it tends to be.

Strategic placement is part of the courtship too. A well-positioned nest can be more appealing to females than one that’s simply well-woven. Males often build on the highest, thinnest branches, where heavy predators can’t reach. They also orient the entrance away from the prevailing monsoon winds, reducing the risk of rain and gusts disturbing the eggs inside. Poorly positioned nests suffer more losses, so this habit plays a crucial role in reproductive success. For the Baya Weaver, survival begins with smart architecture.

Living in groups also brings shared benefits. Many eyes help spot danger, and birds often band together to drive off intruders. Even outside the breeding season, Baya Weavers stay social, roosting in reed beds and traveling in flocks. During nesting, the colony is filled with noise and activity as males call out and flutter between branches, each trying to prove his nest is the best choice.