Evolution has designated vultures to be the ultimate scavengers. Enormous wingspans allow them to circle in the air for hours. Their beaks, while rather horrifying, are weak by bird standards, made to scoop and eat flesh. However unappealing they may seem, vultures serve an important role in the ecological cycle: processing the dead bodies of animals.

Only 20 years ago, India had plenty of vultures—flocks so enormous they darkened the skies. But by 1999, their numbers had dropped due to a mysterious kidney ailment. By 2008, 99.9 per cent of India’s vultures were gone. It was finally discovered that they had been killed by a drug called diclofenac (a pain reliever along the lines of aspirin or ibuprofen).

Indians revere their cows, and when a cow showed signs of pain, they treated it with diclofenac. After the animal died, the vultures would eat the corpse. And though they boast perhaps the world’s most efficient digestive system, vultures cannot digest the drug.

India banned the use of diclofenac for veterinary use in 2006, but it’s still widely used. The near-extinction of vultures has caused disease in the country, as rats and dogs moved in to take their place—spreading pathogens that would have otherwise been destroyed by the vultures.

Vultures need large ranges to scan for food and undisturbed areas in which to nest. They also need an abundance of prey species since they rely more on chance than their own hunting skills to eat. All of these things have been reduced by human activity. Meanwhile, there is a dramatic increase in secondary poisoning. Vultures feed on carcasses laced with poison, intended to kill jackals or other predatory carnivores. Or they are poisoned by the lead in animals left behind by hunters.

Read the above passage and answer the given question:

What is the message conveyed in the last paragraph of the passage?