North American Landbird Conservation Plan . Rich, R. D., 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.Pahsley, K. V.Rosenberg, C. M.Rustay, J. S.Wendt, and T. C.Will . 2004 . Partners in Flight and Cornell Laboratory of Ornithology , Ithaca , NY . 87 pp . (84 + iii). Free download from http://www.partnersinflight.org/cplan.htm .
The Partners in Flight (PIF) North American Landbird Conservation Plan (plan) promises to be a well-worn, dog-eared publication that federal and state agencies and numerous other organizations and groups will rely on to guide management decisions and to prioritize funding requests for research. Partners in Flight spent years identifying species of high conservation priority. The result now represents a broad consensus as to which species are at greatest risk of extinction. Such lists are enormously valuable to government agencies, private conservations groups, and educators. It provides a clear vision of how landbird populations can be protected and enhanced across North America. If you don't have a copy, get one.
One of the great strengths of this road map to landbird conservation is that it includes all of North America. From the outset, PIF recognized that it is critical to cooperate and coordinate with Canadian, Mexican, Caribbean, and Central and South American partners in landbird conservation because birds must be protected in all phases of their life cycles, not just the north-temperate breeding season. Although this collaborative process has sometimes been slow, and it is still an ongoing effort, it is clearly the only possible way to protect and enhance bird populations over broad landscapes. Similarly, PIF has stimulated cooperation among disparate state and federal agencies and has provided a much needed list of conservation priorities. The plan will go a long way in getting international partners and government agencies working from a common starting point, and this is a major accomplishment.
The plan is divided into two main sections with four appendices and eight tables. The first section, “The Continental Plan,” outlines the vision and its implementation (the centerpiece of the book): “[t]he Plan provides a continental perspective on North American landbird conservation, representing geographic, species, and habitat priorities” (p. 5). In the subsection “Assessing Conservation Vulnerability,” the plan does an excellent job of explaining the process PIF used to develop the “species of continental importance.”
Because PIF aims to keep “common birds common” (p. 5), this plan provides a particularly useful function by identifying “stewardship species.” These more common species are characteristic of a single avifaunal biome. Because these species have somewhat restricted ranges, they “… merit special attention for conservation attention within their core ranges” (p. 22). For example, Yellow-bellied Flycatcher (Empidonax flaviventris) is largely restricted to the Northern Forest Biome. Because it is common in this biome, it might not be viewed as a conservation priority at a state or provincial scale. But because a very large proportion of the breeding populations is restricted to northern forest, PIF has highlighted its regional importance. This is a novel and useful approach to bird conservation that aims to protect bird populations before they decline.
The section “Continental Landbird Objectives” is especially helpful because it outlines specific objectives for different categories of birds. The plan identifies where information, data, and research for use in making informed management decisions are lacking. The subsection “Landbird Monitoring and Research Needs” clearly points to major priorities such as species without data on population trends, critical habitat components, or even “testing assumptions.” (We particularly concur with this last need.) The final part of the first section, “Taking Action,” provides specific steps for collaboration, education, and research. If international, federal, provincial, state, and regional agencies and private businesses and groups embrace the goals outlined in this subsection, the plan will be serving its purpose by providing the blue print for landbird conservation.
The second section of the plan focuses on species of concern and conservation priorities within each of the seven major avifaunal biomes. Priority species, primary habitats, conservation issues, and recommended actions are identified for each. At this point, the biomes are limited to Canada and the United States, but the plan is expected to be revised every 5 years and new biomes in Mexico, the Caribbean, and Central and South America will surely appear in later iterations of this work.
As an example of this approach, in the Northern Forest Avifaunal Biome, three species are listed as requiring immediate conservation action (Kirtland's Warbler [Dendroica kirtlandii], Bicknell's Thrush [Catharus bicknelli], and Golden-winged Warbler [Vermivora chrysoptera]). Ten species are recognized as priorities for management, and an additional 25 species are identified as important for long-term planning and responsibility.
The plan also provides estimates of population sizes of all the landbird species of continental importance because “… population estimates serve as the critical foundation for setting measurable population objectives at the continental scale” (p. 11). This section will certainly generate the most discussion and controversy. It seems that the strongest reason for wanting to set actual population estimates was to duplicate the successful efforts of the North American Waterfowl Management Plan (Rosenberg & Blancher 2005), which has “… proven to be a very compelling tool for generating billions of dollars for wetland protection and restoration. …” Few in the conservation world will complain if the PIF plan generates similar resources for landbird conservation, but we question whether the population estimates in the plan will facilitate this process.
Methods to generate these population estimates were developed by Rosenberg and Blancher (2005) for a region that spans the lower Great Lakes to Atlantic Canada and Maine. Briefly, an average estimate for any particular species that has reasonable Breeding Bird Survey (BBS) data is generated by obtaining the total average number of individuals recorded on survey routes during the 1990s within a defined geopolitical region. Three correction factors attempt to account for differences in mating status, detection probability based on song, and song period. The adjusted average estimate for each species is then multiplied by the area of the geopolitical region in which the count was conducted and then divided by 25.1 (the approximate area of sampled habitat on a BBS route). Totals for the geopolitical regions are then summed to provide a global estimate. Given that the most robust aspect of this exercise is the abundance estimates from the BBS routes, one wonders why it appeared necessary to go through this remarkable exercise of extrapolation (with numerous assumptions) to derive a population estimate.
Further, if the population estimates do not have credence, we think there will be little value to any estimate of population change and thus the conservation objectives will appear hollow. Although imperfect, we think targets based on BBS trend data would have much wider acceptance and would require fewer assumptions. One could easily say that the goal for species X was to increase the population to BBS trend levels in a particular region in year Y. Another alternative would be to forgo population estimates and examine changes in species occupancy rates on BBS stops and routes. Regional and local objectives could be stated in relation to maintaining specific occupancy rates for each species on routes where the species is present. These alternatives would keep the objectives tied more closely to the index the BBS data provide.
The problem of population estimation where assumptions are violated becomes more acute for species that are not readily detected on BBS routes. The plan includes an explanation of “accuracy rating and precision,” but even “fair estimates” are thought to be only in the correct order of magnitude (p. 81). Methods for deriving these estimates are vague and their utility in aiding in conservation questionable. For example, estimates of Saltmarsh Sharp-tailed Sparrow (Ammodramus caudacutus: 250,000 individuals) and Nelson's Sharp-tailed Sparrow (Ammodramus nelsoni subvirgatus: 510,000) in the Eastern Avifaunal Biome are simply guesses based on no quantitative data.
We are not convinced that this exercise will provide the necessary guidance for conservation planning or outweigh the risk of loosing credibility. We hope the authors are correct about the utility of setting population targets to generate new resources necessary to implement the plan. But given that nearly one-quarter of the 448 species warranted inclusion on the PIF watch list and that discussions on appropriate population estimates are likely to go on for decades, measurable conservation action will need to be in place long before the uncertainty in these population estimates is reduced or resolved.
Overall, we think the plan does an excellent job of summarizing the conservation status of North American landbirds, identifying species in need of immediate attention, setting a vision to keep common birds common, promoting bird conservation throughout the seasonal cycles, and demonstrating the need for greater landbird conservation resources. The plan provides a much-needed road map to meet landbird conservation objectives, and it provides a means to focus limited resources in a coordinated approach to landbird conservation that should help “keep common birds common.” The value of the global population estimates, however, is tenuous at best.
Ultimately, to be effective, any continental conservation plan—be it for birds, amphibians, watersheds, or ecosystems—must be broad and visionary. To be really effective, a plan needs to go beyond a vision statement. It must provide enough detail and “reality check points” to capture, engage, and stimulate a very wide audience. In large measure, we think this plan succeeds.