Sandhill and Whooping Cranes: Ancient Voices over America's Wetlands

Driving west from Lincoln to Grand Island, Nebraska, Paul A. Johnsgard remarks, is like driving backward in time. "I suspect," he says, "that the migrating cranes of a pre-ice age period some ten million years ago would fully understand every nuance of the crane conversation going on today along the Platte."

Johnsgard has spent nearly a half century observing cranes, from a yearly foray to Nebraska's Platte River valley to see the spring migration, to pilgrimages to the birds' wintering g...