Book excerpt: Squirrels of the World, written by scientists with more than 100 years of collective experience studying these popular mammals, is the first comprehensive examination of all 285 species of squirrels worldwide. The authors reveal virtually every detail of the family Sciuridae, which includes ground squirrels, tree squirrels, flying squirrels, prairie dogs, and chipmunks. Each species—from the familiar gray squirrel of American backyards to the exotic and endangered woolly flying squirrel of Pakistan—is described in a detailed account that includes distinguishing characteristics, ecology, natural history, conservation status, and current threats to its existence. Squirrels of the World includes • stunning color photographs that document rare and unusual squirrels as well as common varieties• evolution, morphology, ecology, and conservation status• colorful range maps marking species distribution• images of the skull of each genus of squirrel• extensive references -- Lawrence Heaney, Curator and Head of the Division of Mammals, The Field Museum (Chicago)