I ndia can still surprise us—and for the better. We have all heard this statistic time and again: one in six humans in the world lives in India. But there’s also an array of plants and animals, reptiles and fishes that shares with us our living space. This is a cause for both celebration and concern. Can we retain this irreplaceable wealth of nature even as we aspire for a better future for our human selves? It’s not just our human population—with its plurality of faiths, languages and ethnic groups—that expresses India’s spectacular fecundity and diversity. We are the only country to have lions in the wild as well as tigers: they exist in nature, not in captivity. The snow leopard, that ghostly phantom of the mountain peaks photographed first in the mid-1970s, is found across five Himalayan provinces. To these add myriad forms of fish and amphibians, and only the second monkey species to have been recorded by scientists in Asia in a century—the Arunachal macaque. That’s just a small ...