LILY POND; Four years With a Family of Beavers <i> By Hope Ryden (Harper: $8.95, illustrated) </i>

Hope Ryden spent four years observing a group of beavers in an Upstate New York park, but she seems to have been more interested in making pets of these interesting animals than in observing their natural behavior. Her descriptions read like an icky-cute storybook: “When a number of beavers feed together on a tree they have felled, they look and act like a party of well-bred gnomes enjoying a picnic.” This little-furry-brother school of nature writing tells the reader little about beavers but a lot about how people try to make animals fit into their notions of what nature is supposed to be.