by Bil Gilbert. Knopf, $7.95. Chulo is the Southwestern name for the coatimundi, a well organized relative of the raccoon. As one local put it, “They take care of themselves, don’t bother anybody, and aren’t afraid of anything. They are smart and pretty and they are good to each other.” Mr. Gilbert spent months studying chulo and has written delightfully about these thoroughly charming animals.