Book review: Gyrfalcons and Ptarmigan in a changing world

Gyrfalcons and Ptarmigan in a Changing World. Edited by Richard T. Watson, Tom J. Cade, Mark Fuller, Grainger Hunt, and Eugene Potapov. 2012. The Peregrine Fund, Boise, Idaho, U.S.A., 2 volumes, 372 pp., 400 pp. ISBN 9781461129073, 97814699 43305. Paperback: maps, photos, figures, tables. Price $37 each volume or free online.—The Peregrine Fund has published proceedings of several conferences over the years and has become expert at the task, and this 2-volume set is no exception. The title of the proceedings sounded especially interesting in this era of almost daily accounts in the media about climate change, its causes and its effects on the planet, including its flora and fauna. From the Preface, it was noted that climate change modeling predicts large alterations in species’ distributions and the potential for extinctions; however, phenological factors involving predatorprey interactions and interspecific competition add levels of complexity that make forecasting difficult. So, this proceedings provides an opportunity to discover, first hand, what is occurring in the Arctic (a region where earliest responses are expected in a relatively simple ecosystem where processes are perhaps easier to understand) with the Gyrfalcon (Falco rusticolus), and virtually its only prey (ptarmigan) available during courtship and incubation in most regions. Volume I includes an overview of Gyrfalcons, ptarmigan and the Arctic, plus Gyrfalcons and ptarmigan in North America. Volume II includes Gyrfalcons and ptarmigan in Greenland, Iceland, Scandinavia, and Russia, plus related raptor species (mostly Peregrine Falcons [F. peregrinus]) and monitoring and conservation strategies. The Peregrine Fund, together with Boise State University and U.S. Geological Survey, convened the international conference in February 2011 on the ecology and conservation of the Gyrfalcon with special emphasis on the three species of ptarmigan with which it has a strong predator-prey relationship. The conference was attended by 120 experts in the fields of climate change, the arctic ecosystem, the natural history and ecology of Gyrfalcons, other perhaps competing raptors, ptarmigan, seabirds and mammals, and the conservation, management and monitoring of these species. The proceedings includes 52 peer-reviewed papers, four republished papers, six extended abstracts, eight abstracts and three oral paper transcripts. It is strongly recommended that readers first read the ‘‘conference summary’’ by Ian Newton, prior to reading any of the individual papers. Newton has a special way, based on his long career as a researcher and writer, of placing the findings from many sometimes unconnected individual reports into a unified perspective. His assessment also concludes with a section on priorities for future work. Several general concepts provide the foundation for much of the information presented at the conference. The response of a predator species to climate change will be influenced by the responses of its prey and competitors, and so forth throughout the food web. Furthermore, the complexities of ecological systems warrant sensible approaches for assessing and establishing the role of natural climate variability in order to substitute inferences about the potential effects of global warming (Douglas). Two non-raptor examples from the Arctic provide some excellent perspective. Amstrup reported that because polar bears (Ursus maritimus) depend upon sea-ice (and sea-ice dependent seals for food), habitat that literally melts away as temperatures warm, projections of the future are more straightforward for polar bears than for most other species. A longterm dataset on Black Guillemots (Cepphus grylle mandtii) provides additional insight into how a species in the Arctic responds to climate change (Divoky). This species did not breed in northern Alaska until the 1960s when warming temperatures allowed access to nest cavities for the 80 d needed for successful reproduction. The species thrived in 1970s and 1980s when ‘‘summer length’’ continued to increase and arctic pack ice remained within the 40 km foraging range of breeding colonies. Then, continued temperature increases and reduction in summer pack ice resulted in decreased nesting success by modifying distribution and abundance of prey, competitors, and predators. Lower-quality prey to feed young resulted in brood reduction