It's fine to be female, is the tenor of biologist Mariette Nowak's message as she roams through the animal kingdom, offering an upbeat, un-radical feminist perspective on sexual lives and times. It's a bit of a potpourri, what with chapters on parthenogenesis and the evolution of sexuality, lots on animal behavior and sociobiology, and thoughts on contemporary culture. We are introduced to some new terms: ""proceptivity"" to describe female sexual initiative; ""matrifocal"" for the core maternal-infant unit common in many social animals; the ""uni-male"" group to describe what male observers have called animal harems--but apparently female-offspring groups in which the solitary male's principal role is that of impregnator. Nowak is surprisingly tolerant of some sociobiological tenets--citing, among others, the ""genetic investment"" theories that support male promiscuity and female ""coyness."" Her discussion of the contemporary scene includes personal experiences, like her regret at not sharing the first hours of birth with her babies in light of current theories on bonding. She sees a need for a family-type of day care for children under three, and is generally hopeful that the changing role of women will lead to greater paternal participation in child-rearing. As in all books drawing examples from nature, there is a problem of selectivity; and Nowak's examples of matriarchy and altruism among elephants, mountain sheep, African kudus, and the like, her suggestions of orgasm and menopause in some subhuman primates, her predominant references to female investigators will no doubt raise hackles in the macho camp. On the whole, however, Nowak achieves a balance that makes her book a welcome addition to the behavioral literature.