Principles of Animal Behavior, Second Edition, builds on the first edition "s reputation as a contemporary and forward-looking text with several distinct features: balanced coverage of proximate and ultimate factors, bolstered by a significant expansion of proximate coverage in the new edition thorough coverage of phylogeny and animal behavior has been added to the book "s integrated view of natural selection, learning, and cultural transmission a focus on current research and the process of science through interviews with prominent researchers at the end of every chapter.