Russell Greenberg reviews No Way Home: The Decline of the World’s Great Animal Migrations by David S. Wilcove, in American Scientist:
Conservation biology focuses largely on developing solutions to the human-caused extinction crisis gripping the world’s biota. Somewhat diminished amid the valiant efforts to save threatened species and populations is the complementary goal of maintaining the grandeur of certain natural phenomena, including ones that capture the imagination by virtue of the sheer abundance of organisms involved. A prime example, which David S. Wilcove describes eloquently in No Way Home, is animal migration—the back-and-forth journeys of flocks, herds, pods and schools of animals across plains and seas, and sometimes even hemispheres. These grand migrations have evolved over millions of years to allow animals to take advantage of seasonal flushes of food. Yet the patterns of movement are indeed dynamic and can change noticeably over a fairly short period of time.
No Way Home explores the current precarious state of migration, raising a fundamental question for conservationists: How satisfying will it be to save all of the migratory species from extinction if the flow of migration nevertheless slows to a trickle? Migration is indeed declining. In some cases the changes have been abrupt and obvious, but more often they have taken place so slowly as to be barely perceptible until eventually it becomes obvious that a particular migration is an unrecognizable ghost of the phenomenon it once was.