While briefly introducing four varieties of caribou, most of the text here is devoted to the barren-ground caribou of Alaska, northern Canada, and Greenland. Harris discusses their adaptations (dense coat, specialized teeth and jaw, etc.) and threats to their well-being (insect pests; predators, including humans; pollution; reduced range due to logging, road building, and urbanization; barriers to migration, like the Alaska Pipeline). A generous number of attractive color photos supplements the text, which should be useful to those interested in animal adaptation, conservation, and the effects of man on animal populations. Fact table; glossary; index.