Acclaimed writer Peter Matthiessen, a self-professed "craniac," has been observing and studying all kinds of birds most of his life, but his pursuit of cranes is closer to a spiritual quest than a naturalist"s exercise. These majestic, mythic, and notoriously shy birds, capable of soaring at heights of 20,000 feet, are often fond of remote and rugged places, so just locating the birds can be difficult enough, determining an accurate number often impossible. Some locales, such as the breeding grounds on the Platte River in Nebraska, boast flocks half a million strong--"by far the greatest crane assemblies on earth"; other areas support only a precious few. Matthiessen"s search for 15 different species of cranes has taken him to hidden corners of Siberia, China, Mongolia, Tibet, Sudan, and Australia (where Atherton cranes were not even discovered until 1961). Despite his many years of adventure and wide travels, each crane sighting is still a thrill for him, and his curiosity and contagious enthusiasm bring the book alive. But The Birds of Heaven also serves as an ecological warning: "Perhaps more than any other living creatures, they evoke the retreating wilderness, the vanishing horizons of clean water, earth, and air upon which their species--and ours, too, though we learn it very late--must ultimately depend for survival." --Shawn Carkonen