This is a book review of the third edition of the book Ornithology, by Frank B. Gill, published in 2007 by W. H. Freeman and Company. My experience with this book comes from taking an elective graduate course in the agriculture school, essentially the same as the undergraduate Ornithology course, while studying at the University of Delaware.Summary, appropriate level and audience:The Gill Ornithology book is engaging and written in a captivating, accessible style, yet it is simultaneously dense and nuanced. It is without superfluous flowery language or unnecessary repetition. The book also makes outstanding and frequent use of examples, drawing from species around the globe.The effect of this book’s use of examples is that, by the end of reading the whole text, the student or reader will not only have a good understanding of the abstract ideas, trends, and general theories of the subject of ornithology, but will also have a fairly broad array of examples of different species of birds, and their particular traits, ecology, and evolutionary history.I think that the best audience for this book would be advanced undergraduate students who are adept at reading scientific texts and who have some introductory understanding of biology and ecology, or graduate students in more tangentially related fields who wish to acquire a good overview of the subject of ornithology. Although this book would make a great choice of a textbook for a standard undergraduate ornithology course (and it is widely used as such), I think it would also make an outstanding text for self-study.The book is long, however, and getting through the whole text and getting the most out of it will consider a considerable investment of time in reading. In order to cover this text in a single semester-long course, students will need to read and reflect on a substantial volume of fairly dense writing nearly every day. However, the invested time will be well worth it, in terms of the deep understanding of the subject that can be obtained from this book.Third Edition vs. Second Edition:When dealing with textbooks, one major question asked by professors and students alike is: “Can I get away with using an earlier edition of this book?”Unfortunately, in many fields of academic study, a number of mainstream academic publishers have fallen into engaging in the unscrupulous practice of publishing unnecessary new editions of textbooks, in order to increase their own profits. The business model is dishonest, and works as follows: by releasing a new edition, publishers decrease the market value of old editions, and increase the rate by which students buy new books. Often, new editions consist of little more than a shuffling of topics, and represent little or no improvement in past editions, sometimes even introducing as many errors as they correct.The Gill Ornithology text is not an example of this “edition creep”. The third edition is truly revolutionary, as textbooks go. Although the second edition of the Gill text was an outstanding, authoritative text at the time it was written, the field of Ornithology has radically changed since 1994, when the first text was published. The third edition text not only references ample newer studies and cutting-edge work, but it reflects a deep critical re-examination of the field as a whole. Gill shows a clear enthusiasm for the subject of ornithology, and the changes and revolutions that have been happening in this field in recent years. And lastly, the third edition demonstrates influences from developments and changes in other, broader fields of study as well, such as ecology and climate.The topics in the book that have most changed since the earlier edition are those pertaining to bird intelligence, the updating of taxonomic and evolutionary relationships due to change, and updates on conservation issues. However, nearly all of the Gill text reflects thorough updates based on modern studies.In summary:Frank B. Gill’s Ornithology is an outstanding textbook on the subject of ornithology, and is suitable for classroom use for advanced undergraduates or graduate students, and is also outstanding for self-study. The third edition represents essential updates from the second edition, and I would absolutely recommend for anyone to buy the third edition rather than the second.