Animal migration is a magnificent sight: a mile-long blanket of cranes rising from a Nebraska river and filling the sky; hundreds of thousands of wildebeests marching across the Serengeti; a blaze of orange as millions of monarch butterflies spread their wings to take flight. Nature's great migrations have captivated countless spectators, none more so than premier ecologist David S. Wilcove. In No Way Home, his awe is palpable--as are the growing...