Davis is a superb natural historian with a lyrical feel for the eagle's world—its quirks, its habits and its extraordinary survival skills. He sketches vivid portraits of the artists, scientists and eagle-loving eccentrics who thought nothing of perching in a tree for weeks to document eagle life. These character sketches do overstuff the narrative, which might have been better served by focusing on fewer outsized personalities. Still, this is an extraordinary and fundamentally optimistic story, and it sends a message we need to hear, as we face the formidable environmental challenges of the 21st century..