India, July 29 -- The dead tree has no leaves. The leaves have been replaced by birds, hundreds of birds.

This rainy afternoon, every branch is occupied. Black kites sit almost wing to wing along the tree's bare limbs. Every few seconds a bird takes off, a bird lands. Some birds arrive carrying twigs in their claws. Others sit motionless for minutes.

The tree stands beside the busy Lodhi Road in Central Delhi, flanked by trees. The crowns of the neighbouring trees are thick with green leaves. They may hold just as many birds, but their leaves conceal them. This bare tree displays every visitor.

Beside the tree is a dump yard strewn with food refuse, including chicken and mutton bones, from the nearby eateries. Every evening, the stilln...