In the book, a series of guide-determiners of the geographer and traveler tells about all representatives of the mammal class, gives their characteristics, gives information about habitats, nutrition and reproduction, about the harm or benefits that they bring. It has color 'portraits' of all our mammals. In addition, 62 bar drawings given in the text will help determine which animal belongs to certain paw prints, as well as get acquainted with the types of nests belonging to various birds. With the help of the guide, the naturalist will be able to quickly and correctly determine the name of the animal he met and immediately learn about its lifestyle, geographical location and economic significance.