John Faaborg. 2002. University of Texas Press. Austin, Texas. xvi + 226 pp., 11 photos, 21 figures. Paper, ISBN 0-292-72548-5, $22.95. Hardcover, ISBN 0-292-72544-2, $50.00.—Saving Migrant Birds is an often witty and consistently provocative look at the scientific evidence that caused widespread concern for the plight of Neotropical migratory birds and led to the development of the Partners in Flight (PIF) bird conservation initiative. Told through the eyes of John Faaborg, an esteemed avian ecologist, the book questions whether Neotropical migrants are indeed in dire need of conservation attention and whether the response by the conservation community (i.e. PIF) was truly warranted. Faaborg does, however, go on to suggest that the future of bird conservation and our ability to thwart new threats to migratory bird populations will certainly be helped by the research, communication, coordination, and bird conservation planning that have resulted since PIF's inception. The author does an excellent job with the subject matter, providing a clear explanation of how the science that is guiding much of bird conservation today developed. Sprinkled throughout are many anecdotes of how he, his students, and closest colleagues continually reviewed and questioned evidence that derived from their own research, as well as that of others; these provide a refreshing “insiders” look at scientific scrutiny at play.
The book begins with a discussion of the evidence of declines in migratory bird populations in late 1980s, and examines both the strengths and weaknesses of the Breeding Bird Survey, Breeding Bird Censuses, banding studies, radar ornithology, and other sources of trend information. Subsequent chapters discuss mechanisms that can affect Neotropical migratory bird populations during the breeding season as well as in migration and on the wintering ground. Issues associated with the breeding grounds are presented in an historical sequence, beginning with the island theory of biogeography and its original application to mainland systems, the discovery of area-sensitivity and species-area curves, and edge effects. Faaborg moves from there into a detailed description of source—sink dynamics and the evidence that populations are regulated at a landscape scale.
The section on breeding-bird ecology is followed by a chapter on modern management practices. Much of what is presented here is at the heart and core of PIF bird-conservation plans that Faaborg later describes as “state of the art.” Included are important concepts regarding habitat quality and quantity; the need to protect large landscapes that serve as population “sources”; and the value of forest management, including some amount of clearcutting, which appears to provide important postbreeding habitat for forest-breeding birds.
The chapters on wintering ecology and population limitations in winter are equally well-developed, covering resource abundance and habitat selection, interand intraspecific competition, social structure, and related constraints that can affect fitness. Explanations of the logistical difficulties associated with attempts to measure survivorship and fitness of migratory birds give the reader a feel for some of the challenges that researchers face. A relatively brief chapter on migration ecology addresses the high energetic demands of birds in transit, questions whether there actually has been a reduction in stopover habitat in recent decades, and describes various natural and unnatural barriers Neotropical migrants can encounter.
After careful consideration of the research and trend data to date, the author concludes that “we no longer should be concerned with widespread declines in large numbers of Neotropical migrant bird species” and challenges whether widespread population declines ever really warranted the massive response by the conservation community. He fails to mention, however, that PIF quickly began to move away from looking only at population trend as a reason for concern, and that within a couple of years of PIF's inception, had developed a species prioritization scheme that included seven parameters that relate to a species' vulnerability to extinction. Population trend is only one of those; the others are global abundance, global extent of breeding and nonbreeding distributions, threats during breeding and nonbreeding periods, and the importance of an area under consideration for conservation of the species (Hunter et. al. 1993a). That prioritization process was continually refined through the 1990s (Carter et. al. 2000) and is still undergoing careful scrutiny and revision as a species assessment tool for all landbirds, both resident and migrant, in the northern hemisphere (K. Rosenberg pers. comm.).
Faaborg then goes on to say that at the time PIF was developed, nearly all the concern was focused on migrants that lived in forests, and now he feels the most convincing data about actual widespread declines have come from birds associated with grasslands. There is a further implication that PIF did not—and may still not—be giving grassland birds the conservation attention they deserve. Although he is correct about the initial focus being on forest-breeding Neotropical migrants, by the first PIF conference at Estes Park, Colorado, in 1992, the prioritization scheme mentioned above was considering a much broader avifauna than forest-breeding Neotropical migrants and began to highlight at least some grassland and grass-shrubland species as priorities for conservation action (Carter and Barker 1993, Hunter et. al. 1993b, Smith et. al. 1993, Thompson et. al. 1993). By the mid-1990s, when the first PIF national and regional coordinators were hired to develop bird-conservation plans for the United States, suites of priority grassland and grass-shrubland breeding bird species were emphasized in every planning unit with manageable populations (Pashley et. al. 2000), and many notable conservation efforts on behalf of grassland birds are now underway.
Despite questions of whether declines of forest-breeding Neotropical migrants warranted the PIF response in the first place, Faaborg praises PIF for the role it has played and continues to play in bird conservation. He notes that PIF served as a strong impetus to getting biologists and other staff from various conservation agencies and organizations communicating in ways that had never been achieved before; promoted a new emphasis on nongame birds; fostered and focused research on mechanisms that can cause bird population declines; and helped to bridge the gap between research and management. He also praises the proactive efforts of PIF to “keep common birds common” and explicitly states that “PIF's state-of-the-art conservation programs… will work to save migrant birds not only now but well into the future, when the many potential limiting factors we have discussed in this book will eventually be at work.”
The final chapter, “Partners in Flight: How it Works and How You Can Help,” describes the variety of entities, agencies, and organizations that constitute the PIF community and suggests ways the reader might become involved with the initiative. John Fitzpatrick (2002) recently made a more direct call for participation by The American Ornithologists' Union members in both PIF and the North American Bird Conservation Initiative and this book also provides an overview of the importance of those programs to conservation. A few changes in PIF infrastructure have taken place since its inception and a new PIF continental conservation plan and strategic plan are now being developed. Interested readers should visit the PIF website for the most current information about Partners in Flight (www.partnersinflight.org). One notable change since Saving Migrant Birds was published is that the PIF Regional Coordinator positions are no longer being funded and those staff members have had to move on to other positions.
Saving Migrant Birds should be easily understood by any biologist, including those who are not ornithologists by training. It would be of great help to biologists and planners working within agencies and organizations involved in the implementation of PIF plans who seek to understand the biology that underlies many of the recommendations therein. Although I also would recommend it to amateur bird watchers with a serious interest in conservation, I think it would be too technical for the casual birdwatcher despite the author's relatively casual writing style. The book belongs in all university libraries as well larger community libraries and the personal collection of those with a serious interest in bird conservation.