John J. Videler Oxford University Press (2005) 258 pp. ISBN 0-19-856603-4 £55.00
Birds are spontaneously intriguing to humans - witness the economics of the industry associated with bird watching and backyard feeders - and birds are often the subjects of behavioral, ecological,and physiological research. Mastery of locomotion through the air is the most interesting aspect of birds. Understanding the mechanisms and functional significance of flight is vital to understanding the biology of birds, so it is puzzling that relatively few biologists, among the many fascinated with birds, have chosen to focus their research upon flight. Possibly, avian biologists are reluctant to get involved in flight research because the aerodynamic models and underlying mathematics are initially intimidating. Unfortunately, virtually all books related to the subject begin with these fundamental, formidable issues, and some substantial proportion of readers never get past the introductions to join first-hand in the science uncovering the mystery of flying birds.
John Videler's book takes a different approach in its overview of avian flight and should, therefore, serve as a potent recruiting agent to draw students of birds into the lair inhabited at present by somewhat lonely flight mechanists and theoreticians who, present company included, run the risk of intellectual inbreeding given their small population size. With mathematics relegated to ancillary boxes, the focus of this book is to establish what is fascinating about avian flight, placing this fascination in the context of existing research, and generously pointing out promising directions for future exploration. The author's unbridled enthusiasm, contagious in a good way, is apparent from the preface onward as he weaves in stories of his personal experiences studying bird flight. Tables are few in number, common names are employed, jargon avoided, and plentiful black and white illustrations, often redrawn from the original source to improve clarity, support the text. References are included throughout, so interested readers may seek out original sources for further information.
The book is organized into nine sections, the first of which is a particularly unique journey through the history of human interest in animal flight, beginning with Aristotle and continuing through to various researchers using modern technology during the past several decades. The author touches upon the startlingly creative work of broadly recognized (e.g. Da Vinci and Newton) and many less-famous historical figures, highlighting how developments in the fields of physics, mathematics, fluid dynamics and engineering have informed our modern interpretation of animal aerodynamics. At the end of this section, the provocative theme of the book has emerged: the history of science has given us a reasonable understanding of low-speed, steady aerodynamics,and, as a scientific community, we are now in possession of the techniques to fully test how such a seemingly tidy body of knowledge, well applied in engineering circles, relates to the apparently untidy, frequently unsteady,and potentially non-optimal solutions that have evolved among birds.
After this enthralling overview, which, of necessity, is light on detail,subsequent sections explore in somewhat greater depth the functional morphology, evolution, kinematics, biomechanics and metabolism of flight. Treatment is still relatively brief, but this brevity fosters a nimble discourse, and it leaves sufficient space for what is a key strength of the book: many new functional interpretations are, for the first time, summarized in an easily accessible form. For example, the internal anatomy of the wing is presented in schematic form with one additional illustration giving muscle detail. Such information is often available in ornithology or comparative anatomy texts. In contrast, Avian Flight features something that hasn't yet made the leap from the original literature into many textbooks: the wealth of insight into functional morphology that has come from using techniques such as electromyography, in vivo strain-gauge implantation and high-speed cineradiography. Similar examples of the author reviewing exciting new evidence instead of merely restating untested dogma are apparent in the presentation of the author's own `Jesus-Christ dinosaur hypothesis' for the origin of flight based on the Basilisk lizard's ability to run on water, summaries of new fossil discoveries, flight plans and intermittent flight, the scaling of metabolic costs during flight and mass-loss during flight.
In a field with implications as broad as those of avian flight, inevitably a few specific areas were not included. Given the potential for the book to serve as a catalyst for new researchers in the field of avian flight, the omission that is most sorely missed is a phylogenetic context for comparative data. When describing scaling, of morphology or metabolism, no mention is made of hypothesized interrelationships among species that require the use of phylogenetic techniques for tests of statistical significance. Likewise, in the section of the book on the origin of flight, the need to use cladistics,and to map the direction of proposed evolutionary change on a clade, is not included. Comparative biomechanists, perhaps inspired a little too much by mechanical engineers whose work has nothing to do with phylogeny, need to be reminded whenever possible that phylogeny is a potent alternative hypothesis for observed patterns, and this book would be an ideal place for such a reminder.
Regardless, the book does a splendid job of conveying the reasons for the author's enthusiasm for studying avian flight, for why we are currently at a crossroads where new discoveries will not only change our understanding about how birds accomplish flight but also about how understanding flight is key to all aspects of bird biology. In this capacity, the book will serve as an excellent foundation for seminars for advanced undergraduates or graduates and as an essential motivational tool for all avian biologists. It also represents a highly useful supplement to any ornithology, functional morphology or comparative physiology textbook. Books that are similar in theme or intended audience include Norberg's Vertebrate Flight, Azuma's The Biokinetics of Flying and Swimming and Dudley's The Biomechanics of Insect Flight. Avian Flight easily ranks as an original and worthwhile addition to this literature.
