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  • Canadian Studies of Amphibian Population DeclineAmphibians in Decline: Canadian Studies of a Global Problem by David M. GreenReview by: Claudia Azevedo-RamosEcology, Vol. 79, No. 7 (Oct., 1998), pp. 2573-2574Published by: Ecological Society of AmericaStable URL: .Accessed: 08/05/2014 11:47

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  • October 1998 BOOK REVIEWS 2573

    authors are trying to get "the data" in the face of one ob- stacle or another, but in reality no real scientific data are presented in this book. In fact, the chapters read more like journal entries with numerous personal details that are often disjointed. Indeed, this is not so much a book about the scientific aspects of conserving an endangered species, but a sociological study of the politics of conservation. In itself that is not a weak point, indeed it is a dimension of the "science" of conservation biology that is all too often ig-

    nored. What can be questioned, however, is whether the same effect could have been better realized in a well-written magazine article that would have a wider circulation among those interested in the environment.


    Moravian College Department of Biology Bethlehem, Pennsylvania 18018-6650

    Ecology, 79(7), 1998, pp. 2573-2574 ? 1998 by the Ecological Society of America


    Green, David M., editor. 1997. Amphibians in decline: Ca- nadian studies of a global problem. Herpetological Con- servation. Volume 1. Society for the Study of Amphibians and Reptiles, Saint Louis, Missouri. xiii + 338 p. $39.00, $55.00 (Canada), ISBN: 0-916984-40-0.

    During the First World Congress of Herpetology in 1989 in Canterbury, England, scientists were surprised by several reports about the disappearance of amphibian populations in many parts of the world. Soon after, the World Conservation Union (IUCN) established the Declining Amphibian Popu- lations Task Force (DAPTF) with regional working groups in several parts of the world. Their main goal was to determine the status of amphibian populations in each region and report the information to central DAPTF, which would evaluate the existence of global causes for the decline of amphibian pop- ulations. The Canadian Declining Amphibian Populations Task Force (DAPCAN) works as one of these regional work- ing groups. According to W. R. Heyer, chair of DAPTF and author of the foreword of this book, DAPCAN is of strategic importance because amphibians at the edge of their geograph- ical distributions are under greater environmental stress and, therefore, would be the first to feel eventual global changes that adversely affect amphibians.

    Therefore, I had great expectations when I started reading this book, especially because it was introduced by its editor, David Green, as the product of four DAPCAN conferences (although some of the chapters were not presented as papers at the conferences). My expectations were based on the title of the book and on DAPCAN's mission as stated in the book's preface: "To determine the nature, extent, and possible causes of declines in amphibians in Canada, and advocate means by which the declines can be avoided, halted and reversed." Despite this clear statement of mission, the chapters vary considerably in relevance to this central theme. The book has 29 chapters. Although the chapters are not organized the- matically into sections, which would have helped readers, they cover a wide range of subjects, including population and community biology (eight chapters), geographic distribution (three chapters, one of them with the unexpected change in format of three papers in one chapter), genetics (two chap- ters), methods of monitoring populations (eight chapters), anthropogenic impact (six chapters), disease in amphibians

    (one chapter) and a final chapter discussing the decline of amphibian population in general. The book also has two ap- pendices, one with current information on the status of 45 species of amphibians found in Canada and the other con- taining a list of present and past coordinators of DAPCAN.

    All manuscripts were peer-reviewed by a body of qualified reviewers, who certainly helped in the presentation of chap- ters, which are concise and have objectives centered in a specific theme. Although the chapters were uneven in quality, all presented relevant information for those interested in gen- eral aspects of amphibian population biology. In some cases, the information contained in different chapters would be more accessible if it had been condensed in a single chapter, as for example those describing call counts and road transects using volunteers, or those describing geographic distributions. I particularly liked David Green's chapters "Temporal varia- tion in abundance and age structure in Fowler's toads, Bufo fowleri, at Long Point, Ontario" and "Perspectives on am- phibian population declines: defining the problem and search- ing for answers," Carolyn N. L. Seburn et al.'s chapter "Northern leopard frog (Rana pipiens) dispersal in relation to habitat," Graham J. Crawsham's chapter "Diseases in Ca- nadian amphibian populations," and Richard J. Wassersug "Assessing and controlling amphibian populations from the larval perspective."

    However, for a book titled Amphibians in decline: Cana- dian studies of a global problem, it is surprising how many of the chapters just marginally approach this subject. Many are the results of studies in one or two reproductive seasons, which makes it difficult to determine the status of the pop- ulation as it is very difficult to separate decline from natural fluctuations. This point was in fact made in at least 11 chap- ters. The chapters also vary in format. Some are reviews of a subject, others are results of research. Some only present qualitative data and many are centered on the discussion of techniques. The result is that the reader may pass through the majority of the chapters without having a clear idea of the status of amphibian populations in Canada and, at the end, reach the inevitable conclusion that there is still much to be done to obtain this answer. However, David Green's excellent summary chapter "Perspectives on amphibian population de- clines: defining the problem and searching for answers" re- deems the book's original objective and brings the other chap- ters together around the central theme. He also suggests

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  • 2574 BOOK REVEEWS Ecology, Vol. 79, No. 7

    changes in the current approach to studies of amphibian pop- ulation decline. From Green's chapters it is also possible to obtain information that the reader was probably eager to learn, such as that 17 of 46 species of amphibians in Canada have suffered losses of population; that more than a human lifetime would be necessary to determine whether apparent declines are a significant departure from random or from normal levels of extinction, so we have to find other ways to monitor pop- ulations; that there is no information on minimum viable pop- ulation size for any Canadian amphibians; that there is no evidence that global causes are behind amphibian declines in Canada, or that ozone depletion, ultraviolet radiation, or acid rain are directly responsible.

    Appendix I, which reports current status of amphibian spe- cies of Canada and presents black and white pictures for most of them, also helps one understand which species are con- sidered in decline. In a future edition of the book, I would

    suggest turning this appendix into an introductory chapter. This would avoid the use of the artifice of distributing pictures of one amphibian species per chapter throughout the book, which makes no sense when a chapter treats more than one species. I do not believe that the stated objective of the DAP- CAN was achieved with this book. However, undoubtedly DAPCAN is interested on organizing professionals beyond a strict focus on amphibian population biology and the results of this effort can already be seen in the diversity of subjects covered in this book. I strongly recommend this book to any- one interested in amphibian studies as a valuable compendium of current studies that are being undertaken in Canada.


    Universidade Federal do Pard DPE/Centro de Filosofia e Ciencias Humanas 66070-100 Belim, Pard Brazil

    Ecology, 79(7), 1998, pp. 2574-2575 ? 1998 by the Ecological Society of America


    Licht, Daniel S. 1997. Ecology and economics of the Great Plains. Our Sustainable Future. Volume 10. University of Nebraska Press, Lincoln, Nebraska. xii + 225 p. $45.00, ISBN: 0-8032-2922-4 (alk. paper).


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