Marine Mammals of California, New and Revised edition (California Natural History Guides)
Robert T. Orris Senior Scientist at the California Academy of Sciences. He is the author and co-author of 15 books includingAnimals in Migrationand two other volumes in the University of California Press Natural History Guide Series.Roger C. Helmhas done research on the abundance and distribution of marine mammals, taking part in the most extensive aerial survey ever conducted. He is now with the Division of Environmental Studies, University of California, Davis.Jacqueline Schoenwaldis a Research Associate at the California Academy of Sciences. She has illustrated four other books.