Susan McGrath in Smithsonian Magazine:
The long-billed vulture, Gyps indicus, is one of three vulture species that serve as sanitation engineers in India, Nepal and Pakistan. For thousands of years, they have fed on livestock carcasses. As many as 40 million of the birds once inhabited the region. Obstreperous flocks of vultures thronged carcass dumps, nested on every tall tree and cliff ledge, and circled high overhead, seemingly omnipresent. In Delhi, perching vultures ornamented the tops of every ancient ruin. In Mumbai, vultures circled the Parsi community’s hilltop sanctuary. Parsis, who are members of the Zoroastrian religion, lay their dead atop stone Towers of Silence so that vultures can devour the flesh. This practice, according to Parsi tradition, protects dead bodies from the defiling touch of earth, water or fire.
But across the subcontinent all three species of Gyps vultures are disappearing. Dead livestock lie uneaten and rotting. These carcasses are fueling a population boom in feral dogs and defeating the government’s efforts to combat rabies. Vultures have become so rare that the Parsi in Mumbai have resorted to placing solar reflectors atop the Towers of Silence to hasten the decomposition of bodies. International conservation groups now advocate the capture of long-billed, white-backed and slender-billed vultures for conservation breeding.