This book is a record of raven behavior from field observations in the wild and controlled studies in an aviary. Heinrich reports others’ studies along with his own and includes others’ single observations along with his own. In the "Afterword" he indicates his move beyond behavioral ecology. Heinrich, while acknowledging the benefit of controlled studies, also values the single anecdote. Both are used to raise new questions as well as to answer old ones, to challenge old theories and posit new ones. He also notes the need to study behavior in the context of the life of the animal and its society.

The book progresses from social observations about mating, territoriality, and hierarchy into observations and studies about mental activity, intelligence, insight, and questions of consciousness. Definitions are needed. Insight is the ability to anticipate outcomes. "Consciousness, at its simplest level, implies awareness through mental visualization" (336). With this latter definition he parts ways from those who would restrict consciousness to language users, and he opens the door for consciousness in non-human animals.

It is a good read for one interested in science and for those interested in animal intelligence. It is well told without heavy use of technical terms; when they are used, their definitions are near. It is told in language such that lay people can appreciate the accomplishments of the birds. References are listed at the end of the book by chapter number for the researcher who wants to delve deeper.