A Bird That Walls Itself In
The female great hornbill (Buceros bicornis) does something no other bird in India does during breeding season: she enters a hollow tree, and the pair plasters the entrance shut with mud, droppings, and fruit pulp until only a narrow vertical slit remains. She stays inside for up to four months, incubating eggs, moulting her flight feathers entirely, and depending on the male for every meal he passes through that slit. The confinement is not accidental. It is the architectural core of the species' survival strategy.
