The late Salim Ali, the country's pre-eminent ornithologist, too was struck by this oddity.
"The most puzzling thing to me about this phenomenon is that so many species of diurnal resident birds should be on the move when, by definition, they should be fast asleep. The problem deserves a deeper scientific study from various angels," he had written.
The 'avian harakiri', as the locals call it, has in fact shaped the region's history.