In this volume from the Scientists in the Field series, Lourie interviews scientists and staff at the Polar Bear Research Project in Barrow, Alaska. Partly because of data collected there over several decades, the polar bear is now officially designated a threatened species. Dr. Steven Amstrup, a veteran of the project, warns that the major threat to the bears today is loss of summer pack ice due to global warming. Although many parts of the book are worthwhile, the most memorable are details of two polar bear capture expeditions. Researchers track down bears by helicopter, shoot them with tranquilizer dart guns, and carry out a series of measurements and medical tests, which include tattooing the bears' inner lips, marking their backs for identification, and attaching transmitters that enable tracking. Nearly every page of this well-designed book includes at least one clear, color photo or map. The reading level is more challenging than might be expected, given the format. An informative, vicarious trip to the Arctic for polar bear enthusiasts and future scientists.

Lourie takes us to Alaska to observe biologists researching a subpopulation of polar bears, then to the lab to see the care taken to properly process and store the data. Interspersed are commentaries from the project directors, who analyze the data and publicize the results. Crisp photographs convey the massive size of the animals and the details of the equipment needed to do research in such extreme conditions. Bib., glos., ind.

For six weeks each summer, scientists in helicopters chase, dart, capture and tag polar bears on the southern Beaufort Sea near Barrow, Alaska, as part of a long-term study of their behavior. With photographs and real-time description of two such captures, Lourie (Arctic Thaw, 2007) details the searching, tracking, tranquilizing and hands-on measuring and marking that are part of this exciting field work. Some photographs serve as page backgrounds; others are insets with extensive captions. The busy design interferes with the immediacy of the author's account, interrupting it with sidebars and pictures of other trips. Before meeting the two scientists and pilot whose adventures lie at the center of this tangle, readers are introduced to other players: the mechanic who follows the field work in real time on his computer in Barrow and the former and current heads of the project. Between the chapters are four conversations with Dr. Steven Amstrup, former lead scientist, including two about global climate change. The book concludes with a page of polar-bear facts. Readers may give up trying to follow the narrative argument and concentrate on Lourie's stunning pictures of this remarkable creature and its beautiful, icy world. With more emphasis on the science work than the scientists, this entry in the usually excellent Scientists in the Field series disappoints. (glossary, suggested books and websites, sources, index). (Nonfiction. 10-14)

Gr 5-8 Since the 1960s, wildlife scientists have been studying Alaskan polar bears in their native habitat. Tracking aggressive wild animals via helicopter is a far cry from the stereotype vision of scientists working in a temperature-controlled laboratory. The narrative is a detailed description of such daily duties as chasing down the animals, tattooing them for future identification, weighing them, and drawing blood, all conducted in temperatures that can fall to minus 30&6;F. Nighttime chores include cleaning the instruments and repacking them for the next day. The full-color photographs are nothing short of stunning. They provide images of the animals staring up at the looming helicopter, mother bears with cubs, and scientists carefully and almost tenderly working on the sedated bears. Included throughout are facts about polar bears as well as the impact of global climate change on their chances for survival. Frances E. Millhouser, formerly at Chantilly Regional Library, Fairfax County, VA