North American Owls: Biology and Natural History, Second Edition.—Paul A. Johnsgard. 2002. Smithsonian Institution Press, Washington, DC. xiii + 298 pp., 42 color plates, 12 tables, 76 text figures, 3 appendices. ISBN 1-56098-939-4. $49.95 (cloth).
When evaluating a revision of a book, two questions come immediately to mind: what prompted the new work, and how has it changed from the previous one? In the preface to the second edition of North American Owls, Johnsgard states that in late 1999, some 11 years after the first edition appeared, the publisher asked him to write a new edition. At first, he declined. After all, he reasoned, that same year the owl volume from Handbook of the Birds of the World (Lynx Edicions, Barcelona) appeared, as did König et al.'s A Guide to the Owls of the World (Yale University Press, New Haven, Connecticut). Moreover, the Birds of North America series was nearing completion, and the species accounts for the 19 owls in that work would appear before a second edition of North American Owls would become available. But the idea kept gnawing at him, and Johnsgard decided that if he included the dozen species of owls that inhabit Mexico north of the Isthmus of Tehuantepec, he would have something unique: an owl book devoted solely to the North American continent. Thus, he began work on the new edition, which, impressively, appeared less than three years later.
Despite the addition of 12 species, the new book contains only three more pages than the first edition. This was accomplished by eliminating detailed plumage descriptions for each species, and by decreasing the text's font size and adopting a double-column format throughout the book. The number of color plates has increased from 33 to 42, and the number of references from 470 to around 900. Curiously, Johnsgard added many new references without citing them in the text, or, as it turns out, discussing the new material.
The introductory chapters cover the same topics as in the first edition: evolution and classification, ecology and distribution, morphology and physiology, behavior, reproductive biology, and owls in myth and legend. Most of the material is unchanged from the first edition. For example, I found fewer than 20 new references in the text of the introductory chapters, despite there being hundreds of papers published on these topics since the first edition appeared. Of the 12 tables in the new edition, nine are virtually identical to the originals, and three include three to seven rows of new information. Similarly, 18 of the 21 figures in the introductory chapters are unchanged from the first edition, and three are new.
New color photographs have been added for nine of the Neotropical species, and two photos mislabeled in the first edition have been corrected. Some of the photos are excellent (e.g., plates 20, 29, 31, 35, and 41), but more than half are of captive birds, including several common species. The Northern Pygmy-Owl (Glaucidium gnoma) in plate 23 looks like a taxidermy mount, although the photographer assures me the bird was alive. Why this photo was used, when a lovely wild bird is depicted in plate 20, is beyond me. A similar question could be posed for the author's photos of what appear to be a captive Great Horned Owl (Bubo virginianus), Great Gray Owl (Strix nebulosa), Long-eared Owl (Asio otus), and Short-eared Owl (Asio flammeus); surely, many excellent photos of wild individuals of these species are available.
Although little is new in the introductory chapters, by and large the treatment is sound, and the information provides a useful summary of owl biology. The index is especially handy because it enables one to find each place in the text that a particular species is mentioned. An error carried over from the first edition is the statement that owls have a tapetum, a layer of light-reflecting cells on the retina. For the record, the only birds known to have a tapetum are nightjars. The reddish eyeshine in owls that Johnsgard alludes to is not from a tapetum, but rather from light reflecting off blood on the retinal surface (the same “red-eye” effect seen in photos of humans taken with a flash). This is explained in Graham Martin's book Birds by Night (1990, Poyser, London). Johnsgard cites two of Martin's earlier papers but not the book, and he confuses Graham Martin (an expert on avian vision) with Dennis Martin (an owl expert who does not study vision) when discussing vision on pages 24 and 25, and when citing one of Graham's papers in the references.
What about the species accounts themselves? Of course, information on the strictly Neotropical species is new to the second edition. The treatments for these species are accurate, although Johnsgard relies heavily on several general texts rather than on journal papers. Those who are unfamiliar with these little-known taxa will find the accounts interesting. I enjoyed reading about the breeding behavior of captive Striped Owls (Pseudoscops clamator) gleaned from two papers published in Avicultural Magazine. A minor quibble is that Johnsgard does not mention that Mottled Owls (Ciccaba virgata) and Stygian Owls (Asio stygius) have wandered north to Texas in recent years, a fact that seldom is discussed in field guides.
Much of the information for the species that occur north of Mexico is the same in both editions. This is unfortunate given the many valuable papers on owls that have appeared since Johnsgard's first edition. In fairness, Johnsgard makes good use of the species accounts from Birds of North America, but he tends to do so without citing the original sources, thus repeatedly crediting BNA authors for work published by others. Why he chose to list new citations in the second edition without discussing the information in the text is a mystery to me. When I first saw the book, I turned to the references and was pleased to see so many recent titles. But then I read the disclaimer that among the references are “many post-1988 citations … not specifically cited in the text but that seem important enough to be included, since no recent published bibliography of North American owls exists” (p. 267). Yet, the list of owl citations in Handbook of the Birds of the World is more complete than that in North American Owls, and the Handbook discusses much of that information in its family texts and species accounts.
One gets the impression that Johnsgard simply didn't have the time to read the new citations and incorporate the information into his text. In some cases, this practice led to mistakes. For example, in the Long-eared Owl account one reads that “… second broods in a single season have been reported several times in Britain … but apparently not yet in North America” (p. 207). In truth, double brooding has been documented in this species in North America (Johnsgard cites the paper) but has not been conclusively proven in the Old World. Also in the Long-eared Owl account, Johnsgard states that “breeding density … is fairly low” and that the species is “usually well dispersed and territorial during the breeding season” (p. 205). Had he digested two of the Long-eared Owl papers listed in the references, plus the information in Handbook of the Birds of the World, Johnsgard would have noted that Long-eared Owls sometimes nest in high densities and as close as 10 m from one another. Not cited is Robert Murphy's note on ingestion of nestlings' feces by a female Long-eared Owl (1992, Wilson Bulletin 104:192–193), which probably explains the statement that “… nest hygiene may be lacking” in this species (p. 42). Dubious statements include the notion that some Long-eared Owls remain on territories year round and renew their pair bonds annually (p. 207), and that males may incubate for short periods (p. 209). None of these traits has been documented in the wild from marked birds.
Perhaps I'm being unfair in my disappointment in the species accounts based on a taxon that I know especially well. How about a species I don't know so well, the Spotted Owl (Strix occidentalis)? Surely, it has been the best-studied owl in North America in the last 20 years. Yet, in the six sections of the species account that focus on biology and ecology, only nine papers are new to the second edition. By contrast, the Handbook of the Birds of the World, published three years before Johnsgard's second edition, includes 95 citations on Spotted Owls that were published since 1989. Indeed, omissions of significant new material occur in just about every other species account as well.
On balance, the new North American Owls is informative, albeit not without errors and omissions. You can learn a lot from it, but you won't learn much more than you would have had you consulted the first edition, because the ratio of new material to old is disconcertingly small. Consequently, I cannot recommend that someone who owns the earlier book buy the new one unless they feel that the material on the Mexican species is worth the cost of the book. If, however, your collection of owl books does not include Johnsgard's first edition or the lavish and much more expensive fifth volume of Handbook of the Birds of the World, Johnsgard's new book will provide an adequate introduction to the biology of North American owls at a reasonable price.
