NONFICTION - Oct. 27, 1991

DOLPHIN DAYS: The Life and Times of the Spinner Dolphin by Kenneth S. Norris (W. W. Norton: $21.95; 321 pp.). Dolphins, with their uncanny ability to cock a waggish grin and look you straight in the eye, have given rise to all sorts of embarrassing anthropomorphism. In another book being published this month, for instance, “The Secret Language of Dolphins,” Patricia St. John thanks the creatures for “seeking out the inner me, the one I had hidden even from myself.”

In contrast, UC Santa Cruz professor emeritus Kenneth Norris doesn’t let his considerable love for these “floating Hobbits” overshadow his scientific acumen. Spinner dolphins earn their name by soaring nearly 10 feet above the water in a flickering blur of flukes, fins and body before landing, with a loud percussive smack , in a plume of silvery bubbles. Others have interpreted this behavior at face value, as joyous play, but Norris, after years of research, discovered that the acrobatics are actually a kind of oceanic Morse code: a way to send complex signals about position, intent and activity to fellow dolphins miles away.

Still, even the cautious Norris cannot help but conclude that these mammals resemble us in surprising ways--sharing, for one, our ability to reason abstractly. Learning about these similarities may not only encourage efforts to preserve this endangered species now that its most prominent champion-- Flipper--is no longer swimming on TV, it may help us to understand how to bring out the best in our own species. For example, when threatened, dolphins lose their individuality, swimming like any other schooling fish. But when they feel safe, the young play and the adults begin “reaffirming relationships,” as Norris puts it, “in what looks like a continuing Bacchanal.”