Color photographs of lions up close and in their natural habitat appear on almost every page of this introduction to the big cats. The format of the book consists entirely of numbered one or two sentence facts about lions and their behavior. For example, "Lions are the only big cats with females that look different from males." Although this may seem like a disjointed approach, the facts actually do progress logically (facts about birth follow facts about mating, 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. An opening map illustrates the areas where lions live, and a glossary defines key boldfaced terms. A guide for further reading and a list of web sites will lead readers to other more in-depth resources. This book is a volume in the "101 Facts About Predators" series. 2004, Gareth Stevens Publishing, Ages 7 to 12.