Enchanting study of the life of the beaver, by a veteran nature-writer (Bobcat Years, God's Dog, etc.). Ryden spent many months searching for the fight beaver pond before she stumbled on Lily Pond (""an impressionist painter's vision of what a pond ought to look like"")--a four-acre puddle in Harrison State Park, N.Y. Once she found it, she stayed for four years of nightly observations, watching a family of four beavers (soon to grow into six, then more) work a 150-foot-long, five-foot-high dam. One of Ryden's aims was to solve some beaver mysteries: Why do they slap the water with their tails? (as a warning of imminent danger, and as an act of aggression). Do they show signs of high intelligence? (yes--for instance, a beaver will drag a tree over to the storage area before cutting, saving a lot of needless extra trips). For the most part, however, Ryden seems content to see the world through beaver eyes (""I tried to imagine what it would be like to winter with one's relatives in a totally dark, relatively airless, and overcrowded room. How do beavers keep from getting on one another's nerves?""). Numerous crises heighten her kinship to these large, friendly beasts, to whom she gives names like ""Inspector General"" and ""the Skipper"": the pond freezes over, ""Laurel"" is run over by a car, vandals destroy the dam--this last event provoking a Diane Fossey-like reaction on Ryden's part, as she calls the vandalism ""a heinous crime"" and vows to ""seek vindication."" By contrast, the drawn-out death of ""Lily"" is authentically poignant and speaks well of beaver courage and human compassion. In a class with Sue Hubble's bee books and other outstanding recent natural histories. In short, the most engaging look at the beaver since that 50's sitcom.