In this attractive addition to a new series featuring animals in the wild, a veteran photographer describes the polar bears he studies, including information about habits, physical characteristics, child-rearing practices and their endangered environment. Opening with a suspenseful encounter with a bear with a toothache, the smoothly written text complements striking photographs, some close-up and some showing bears in their usual habitat. Sidebars describing staying warm in the Arctic and hunting like a bear help the young reader connect. Like other books in the series, the text stresses the effects of environmental changes on these vulnerable animals. Although the writer follows the usual practice of calling the polar bear a marine mammal, readers may be confused by text in a sidebar calling it a “land predator” and a caption referring to “land carnivores.” As a follow-up, there are suggestions for how young readers can help bears and how they might research and photograph them along with two pages of fast facts. Pair with Dorothy Hinshaw Patent’s A Polar Bear Biologist at Work (2001) for slightly older readers. (glossary, bibliography, index) (Nonfiction. 7-10)