T. D. Rich, C. J. Beardmore, H. Berlanga, P. J. Blancher, M. S. W. Bradstreet, G. S. Butcher, D. W. Demarest, E. H. Dunn, W. C. Hunter, E. E. Iñigo-Elias, J. A. Kennedy, A. M. Martell, A. O. Panjabi, D. N. Pashley, K. V. Rosenberg, C. M. Rustay, J. S. Wendt, and T. C. Will. 2004. Cornell Lab of Ornithology, Ithaca, New York. 84 pp., 47 color plates, 21 text figures, 8 tables, 4 appendices. Available from Terry Rich, PIF National Coordinator (208-378-5347 or email@example.com) for a requested $10 donation.—In 1989, the Manomet Bird Observatory sponsored a symposium that gathered researchers concerned about perceived declines in populations of birds that breed in North America and winter in the Neotropics. The results of that symposium (Hagan and Johnston 1992) were serious enough that the National Fish and Wildlife Foundation sponsored another meeting in December of 1990, where the Neotropical Migratory Bird Conservation Program, also called Partners in Flight (PIF), was formed to lead conservation efforts aimed at saving migrant birds.
Concern for migrant birds led to a tremendous burst in research activity in the early 1990s, culminating in a massive meeting of researchers and managers at Estes Park, Colorado, in September 1992. Papers from that meeting appeared both as a General Technical Report (Finch and Stangel 1992) and as a publication from Oxford University Press (Martin and Finch 1995). With the Estes Park meeting, the massive committee structure that constitutes PIF was put into place, with the goal of developing state-of-the-art conservation plans that would “keep common birds common.”
Although PIF has been functioning since that 1992 meeting, few widely visible products have resulted from PIF activities since the 1995 book. The proceedings of a 1994 cowbird symposium appeared in 2000 (Smith et al. 2000); a second international symposium was held at Cape May, New Jersey, in 1995 but did not produce any publications; and a research statement from the AOU that was started in the early 1990s finally appeared in 2002 (Donovan et al. 2002). The appearance of inactivity regarding migrant birds is changing: we now have this publication, we will see the results of the third international symposium on migrant birds soon (Ralph and Rich, 2004), and there will be a separate volume on migration (but without a conservation emphasis) early next year (Greenberg and Marra 2005).
After my first reading of the Partners in Flight North American Landbird Conservation Plan, I wondered how much real “plan” there was. I expected details on how one saves migrant birds, but did not find them. I was a bit relieved when the first author of the publication noted at the recent AOU meeting that this really is a “broad-scale, multi-species assessment.” Because detailed planning is so regionalized, they argue that one cannot have a single plan to cover North America. Rather, this publication is the international overview of PIF and how it hopes to conserve migrant birds throughout the breeding, wintering, and migration habitats used by hundreds of species on two continents. This attractive, well-written volume provides the blueprint for PIF, the broad guidelines needed both to conserve birds and to mobilize the many conservation agencies required to preserve such wide-ranging species. It points out priority species and regions and sets population goals, leaving the detailed management work for the nearly 100 regional plans that are either finished or in the works (they can be found at www.partnersinflight.org).
Rather than summarize the detailed structure of the plan, I will summarize the goals of this book with the following questions:
(1) How do we choose priority species for conservation?—Populations of many species are doing just fine; we need to determine which species are vulnerable, so that we can focus limited resources on their future populations. The authors demonstrate the procedures used by PIF to develop assessment scores for each species, how species with high scores are put on the Watch List, and how other species with limited distributions are deemed Stewardship Species. Overall, the assessment process leads to a list of 192 species of “Continental Importance,” which constitute the focus of the PIF plans.
(2) Where do we focus our conservation efforts for migratory birds?—A migrant may spend several months of its annual cycle in two locations, then use a variety of sites when moving between breeding and wintering habitats. Only one of those locations may be problematic and in need of conservation activities, but determining where limiting factors occur is difficult. Using assessment scores from various species, the book presents many maps depicting the distribution of vulnerable species throughout the annual cycle. The authors also present summaries based on avifaunal biomes, point out important areas for those regional lists of birds, and note where species go each winter.
(3) What are the general principles for regional habitat management?—In recent years, we have made tremendous progress in understanding the interaction between avian demography and a variety of measures of habitat, including not only habitat quality, but such modern concepts as habitat size and juxtaposition. The authors advocate the need for landscape-level habitats and a regional focus on management, recognizing that some species will require an overview that incorporates several of the regional conservation plans.
(4) Can we estimate population sizes and establish population goals for the future?—Using recent Breeding Bird Survey (BBS) data and modern habitat-distribution models, the authors have made global population estimates for all North American migratory birds. Those estimates are then converted into population targets for the future, following implementation of the regional flight plans. For example, there are an estimated 14 million Wood Thrush (Hylocichla mustelina) currently; the goal is to increase the population to 21 million in the future.
Concerns about the validity of such estimates led to the meeting of a panel of statisticians who have reviewed the methods used in making them (Thogmartin et al. unpubl. data). Recognizing the difficulty of the task, the panel points out a variety of weaknesses in the approach and suggests ways to improve it, many of which would require changes in how the BBS is run. Given that we still argue about how to count birds in a woodlot, any attempt to estimate bird populations on a continental scale is going to be controversial and require several rounds of improvements. In addition, the simple act of setting future goals based on these data seems to me to present conservationists with several problems, including choice of the target population and the sensitivity of estimates to assumptions in the models. As we try to encourage landowners to adopt conservation practices that often mean some sort of sacrifice, is the argument that we need 11 million more Dickcissels (Spiza americana) going to be a convincing one? I worry that false impressions of precision with these numbers could end up doing more harm than good.
(5) What are our future needs, especially from research and monitoring activities?—Several sections of this document deal with research and monitoring needs for the future. Monitoring needs are suggested primarily for species for which BBS does a poor job. Research needs are primarily those of Donovan et al. (2002). As a researcher, I was struck that their goal that “new research should be applied, and should move away from descriptive, correlative, and short-term work in small geographic areas, to large-scale replicated studies, controlled experiments, and long-term studies of demography” (p. 30) is the exact opposite of the research one can realistically hope to find support for in the current funding climate. The text also seems to imply that research into monitoring is our major need, whereas I have tried to make the case that we know far too little about the demography of these birds to know how to manage for them, particularly in winter (Faaborg 2002). I hope that their plea for more research support is heard, so that researchers can develop scientifically sound basic ecological principles on which to base our management throughout the annual cycle of these birds. I fear, though, that funding for such seemingly basic research is becoming increasingly hard to find.
This attractive book should help revive what I see as lagging interest in the conservation of migratory birds. I encourage anyone who is interested in these species (and that includes nearly all AOU members) to read it and see how the analysis of status and conservation goals fits those species on which he or she specializes. Even though the plan is the product of the best workers we have with regard to Neotropical migrants, I feel that we should consider it a work in progress, because we still have much to learn about Neotropical migratory birds.