The study of herpetology is a nonmonophyletic academic discipline, encompassing organisms as vastly different as frogs and crocodiles. Summarizing this eclectic group of organisms—including the subdisciplines of morphology, evolution, ecology, behavior, and taxonomy—in textbook form is a daunting task. Perhaps for this reason, comprehensive herpetology textbooks have been slow in coming until very recently. Early volumes, such as those by Goin and Goin (1962), Porter (1972), and Goin, Goin, and Zug (1978), were relatively limited in range.
The first edition of Herpetology: An Introductory Biology of Amphibians and Reptiles appeared in 1993 (Zug 1993). This second edition benefits from an expanded team of authors, all of whom are leaders in the field and each of whom brings specific areas of taxonomic and topical expertise, represents a substantial improvement on the first. This revision is larger in size, better illustrated, more up-to-date, and more accurate than the first edition.
Herpetology: An Introductory Biology of Amphibians and Reptiles is intended to appeal to advanced undergraduates and graduate students in herpetology. The book is divided into six sections (evolutionary history, reproduction and life histories, physiological ecology, behavioral ecology, population and community ecology, and classification and diversity) with 21 chapters. Each chapter concludes with an “additional reading” section and a reference list, both of which are useful additions. The broad coverage of research areas and topics makes this edition very appropriate for undergraduate classes.
In addition to these chapters, a glossary of terms, a taxonomic index, a bibliography of over 2000 cited references (the most recent of which is 1999), a subject index, and an author index are also included. Most of these indexes work well, but the glossary seems inadequate—less than six pages in length, with 208 terms defined. Many common herpetological terms, such as ectotherm, venom, and plastron, are absent. The authors state that the glossary is not intended to be complete, but a comprehensive glossary in a textbook intended for undergraduates would seem important.
The production value of this book is quite high, a major improvement on the first edition. Most of the figures are nicely reproduced, and the format of the figure legends has been standardized. This edition also includes 141 black-and-white photos and 184 color photos. The print legibility of the text is high. The numerous color photos that accompany the chapters on the diversity of groups in part VI make the text even more valuable as a teaching aid.
Part I covers the evolutionary history of amphibians and reptiles. Chapter 1 discusses basic systematics concepts such as monophyly, types of characters used in phylogenetic analysis, methods of analysis, nomenclature, and taxonomy, all of which lay the groundwork for later group descriptions. Chapter 2 covers the anatomy of amphibians and reptiles, including development, growth, and basic anatomical systems. This chapter is generally well conceived, but it was surprising to find that some inaccuracies pointed out in the first edition (Wiens 1993) have not been corrected (for example, in the identification and figuring of skull bones). Chapter 3 summarizes the fossil history of amphibians and reptiles with fairly comprehensive coverage of the herpetological fossil record. Some inaccuracies exist in this chapter as well. As one example, the early amphisbaenian fossil Oligodontosaurus is said to be a “shovel-headed form” when it is known only from a partial lower jaw. Despite such errors, this chapter is an impressive overview of the relevant fossil record, something often missing from organismal textbooks.
Part II presents the reproduction and life histories of amphibians and reptiles. Chapter 4 describes courtship and fertilization in various groups, as well as sexual versus asexual reproduction and parental care. Chapter 5 nicely covers such topics as temperature-dependent sex determination, the evolution of viviparity in various groups, and life history evolution.
Part III is dedicated to the physiological ecology of amphibians and reptiles. Chapter 6 is concerned with water balance and gas exchange, chapter 7 with bioenergetics and thermoregulation. These topics are considered in much greater depth than in the first edition.
Part IV treats the behavioral ecology of amphibians and reptiles. Chapter 8 deals specifically with distribution, home ranges, movements, and migrations. In chapter 9, aspects of communication, mating systems, and sexual selection are described. Chapter 10 is concerned with diet and feeding ecology, including foraging modes and prey capture and ingestion behaviors. In chapter 11, modes of defense, including predator detection and avoidance, specialized predator escape mechanisms, and mimicry, are summarized. This section of the book is one of the many areas where the combined strength of the new team of authors is apparent.
Part V presents population and community ecology, as well as conservation biology. Chapter 12 covers topics such as survivorship, population growth and density, and age distributions. Chapter 13 describes community ecology and includes a short treatment of historical biogeography. Chapter 14 discusses the importance of conservation biology to amphibian and reptile populations, with such topics as human impacts on herpetological communities and preservation and management techniques. This chapter is an important addition, considering the declining state of many populations of amphibians and reptiles.
Part VI is the most expansive section of the book (about half), covering the classification and diversity of caecilians, salamanders, frogs, turtles, crocodilians, “lizards,” and snakes. This section is well organized and well illustrated, one of the major strengths of the book. The descriptions of each group include cladograms depicting higher-level relationships, distribution maps, extensive color photographs illustrating group diversity, and summaries of each group's overall biology. One problem in this section, however, is that some of the cladograms represent a single choice from among several competing phylogenetic hypotheses in the literature, which tends to obscure debate in the field and the controversial nature of the relationships among many groups. For example, figure 20.2 (p. 468) illustrates a fully resolved cladogram of squamate relationships, for a group that has been, and continues to be, the subject of much debate phylogenetically. The descriptions of morphological characteristics that define groups in this chapter contain a few inaccuracies, and some of the distribution maps are slightly inaccurate or are inconsistent with the accompanying written descriptions of distribution.
In a textbook of this size and scope, errors are difficult to avoid, especially in the first few editions. In addition to the noted factual errors, a few typographical errors escaped the review process as well. There are also some inconsistencies that point to errors in editorial oversight. These issues do not significantly detract from the overall high quality of this book, however.
Overall, Herpetology: An Introductory Biology of Amphibians and Reptiles is an impressive second edition, a major improvement on the first. It will serve as an important textbook for advanced undergraduate and graduate courses in herpetology, as well as a general reference book for herpetologists.