The format of the book consists entirely of numbered one or two sentence facts about eagles and their behavior. For example, "See-through inner eyelids let an eagle blink without closing its eyes completely." Although this may seem like a disjointed approach, the facts actually are organized logically (facts about baby eaglets follow facts about eagle mating habits, for example). Breaking the facts down into labeled sections or chapters would have been even more helpful, however. Instead, young researchers must either read the book cover to cover or else rely on the brief index. Many of the facts in this volume deal with threats to eagle species' survival. Color photographs appear on almost every page, although the numerous pictures of various eagle types soaring through the air lack variety. A color-coded opening map indicates the world's climate zones and the corresponding eagle species that live there, and a glossary defines key boldfaced terms. A guide for further reading and a list of web sites (although not all the links work) will lead readers to other more in-depth resources. This is a volume in the "101 Facts About Predators" series. 2004, Gareth Stevens Publishing, Ages 7 to 12.