What starts with a shared orange swiftly develops into a firm, enduring friendship as Maggie Michaels, summering in a Nigerian research camp, meets Naomi the western lowland gorilla. Maggie has her own theory about gorilla communication, which dismays the eminent researcher she is working for. Before this diverting book is over, however, she has convinced not only the doubting expert but her animal-park-director father as well. Actually, Maggie has only a short time in Africa to meet and win the trust of Naomi; her real work takes place in the California lab where she and Naomi use Ameslan signs, a computer, and considerable resourcefulness to make conversation. Brenner is conscientious about presenting the ongoing disputes in this field; she uses both real and fictitious names of primatologists when introducing present controversies. She also keeps the story itself interesting. Maggie's parents have separated; she has a slow-starting romance with a sympathetic Australian graduate student; and she learns firsthand about the politics of pure science--her dad can't help much when the funding committee wants a command performance. In the end Naomi flunks her committee tests but has her day in court as the center of an animal-rights battle. A strong vote here for Thinking Gorillas and a satisfying story overall.