Mammalian hair has always had a use in human society: as fur for clothing, in the production of cloth, or in the production of brushes. Scientists, too, make use of mammalian hair as a diagnostic tool in areas such as animal ecology, wildlife biology, and nature management. The identification of hairs found in the field, in the intestine or feces of carnivores, or in the pellets of birds of prey, can yield valuable information on the distribution of mammals and the diet of their predators. With photographs and keys, this atlas aids correct identification by providing data on the color, form, and length of hair and the structure of the cuticula, medulla, and cross-sections.