Where Have All the Birds Gone?: Nature in Crisis

Birds are nature's essential workers, and they are crucial members of ecosystems around the world. Hummingbirds pollinate our flowers; cardinals munch on beetles, grasshoppers, and other pests that damage crops; owls eat rodents that can spread disease; vultures clean up roadkill and other waste. Beyond their practical aspects, birds bring us joy through their songs and beautiful feathers.

But since 1970, nearly 30 percent of all birds in the United States and Canada h...