Nightjars and Their Allies: The Caprimulgiformes.–David T. Holyoak, illustrated by Martin Woodcock. 2001. Oxford University Press, New York. x + 773 pp., 23 color plates, 221 text figures. ISBN 0-19-854987-3. Cloth, $89.50.— Nightjars, goatsuckers, potoos, frogmouths, oilbirds— my spellchecker underlined every one of these words. I love these very unusual birds, and I have never met an ornithologist who did not think them fascinating. To no small degree, they are the reason I got into ornithological research. But despite their power to fascinate, the Caprimulgiformes remain among the most understudied of bird orders. Recently, Cleere (1998) and the various contributors to volume five of the Handbook of the Birds of the World (del Hoyo et al. 1999) provided the first treatments of the order from a worldwide perspective. However, Holyoak's new book—the seventh in Oxford's Bird Families of the World series—is the first comprehensive, scientifically rigorous volume devoted entirely to the world's species, their evolution, ecology, and behavior.

There are two parts to the book. The first provides 90 pages of general information on the Caprimulgiformes: evolution, speciation, biogeography, habitats, feeding ecology, communication, molt, and breeding biology. Figures from important publications in the peer-reviewed literature are scattered throughout this section. Occasionally, the captions do not provide enough explanation about the data contained in the figures (e.g. fig. 5.1), but most of the figures are very effective. The chapter on Evolution and Classification is particularly well done. The controversy involving differences between biochemical and morphological classification schemes is dealt with head-on, including a brief explanation of DNA-DNA hybridization and other molecular techniques. A summary of data from analyses done on the Caprimulgiformes by Sibley and Ahlquist (1990) is provided, along with a summary of the important taxonomic implications of their results. Also, the worldwide perspective in this section is invaluable for anyone contemplating research on this order. For example, although many aspects of the life histories of North American Caprimulgis species have not been studied, those of close relatives on other continents have been; Holyoak summarizes that work, including the techniques used in collecting data.

The book's second part offers thorough accounts of 118 species; for the North American species, these come very close to the detail of the new Birds of North America accounts. The many tables and figures of data presented throughout this section maintain the feel of an ornithology textbook. Morphological data summaries are provided in tabular form for every species. Martin Woodcock's line drawings, especially those depicting morphological characteristics or a sequence of behaviors, are excellent. There are no photographs, which is a fundamental difference between this volume and the one by del Hoyo et al. (1999). While the latter's photographs are excellent and at times spectacular, this volume focuses much more on data instead. Range maps are nice and big and provide more detail than usual about specific sighting locations, subspecies ranges, and the like. But they are also a little more complicated than typical range maps and can be a little busy; you will have to consult the legend. Woodcock's color plates are excellent but usually only show the bird in resting position. Birds in flight are depicted only by line drawings in the species accounts, again always in the same position to facilitate species comparisons. Various color morphs exhibited by some species are not presented.

Although it is an attractive volume, this book is first and foremost a scientific work, the definitive one on the goatsuckers of the world. It should prove an extremely valuable resource for anyone contemplating goatsucker research, but will also be of interest to birders who wish to know more about this order. The expansive, 64-page bibliography (including voice recordings) is a gold mine of information in itself. The book belongs in all university libraries and on the shelf of any professional or amateur ornithologist who is contemplating serious investigation of this wonderful group of birds.