This fascinating book, originally published in 1990 and now available again from The Blackburn Press, focuses on a comparison of the feeding ecology and social systems of the brown and spotted hyenas. Set in the semi-arid region of the Kalahari, the book examines roles and interactions of the two species in this finely balanced ecosystem and highlights the factors and mechanisms responsible for regulating the populations. The hyenas' interactions with other large carnivores are also explored and this too offers novel insights as to their natural behavior. Extracts from the author's field notes form a fascinating feature of the text and convey all the thrill and anticipation of observing these remarkable animals in their own habitat. "Widespread appreciation of this volume seems to have lagged somewhat, undoubtedly the result of an initial lack of promotion when it was first released. It is a first-class book to which every ecologist should have access and which every behavioral ecologist and carnivore biologist should read." J. of Mammalogy, 74, 240 "The solid data, rigorous analyses and lucid discussions result in a prestigious publication that should be read by behaviorists, theorists, ecologists and wildlife managers." African Journal of Ecology, 28, 257 "The great merit of Mills' book then is that it summarizes in a convenient and readable form a huge amount of data from a heroic field study." Animal Behavior 40, 1193 Gus Mills graduated from the University of Pretoria (D.Sc.). He worked for 12 years as a research officer at the Kalahari Gemsbok National Park before joining the Kruger National Park as a specialist scientist to develop a long-term study of predator-prey relationships. He is presently a Research Fellow with SAN Parks and Head of the Carnivore Conservation Group of the Endangered Wildlife Trust.