The book tells in a popular form about the behavior of birds associated with all phenomena of their marital life - courtship, singing, marriages, infidelity and divorces. Using examples of many species from different systematic groups of birds on all continents, various forms of marriage are described - monogamy and polygamy, colonial and cooperative breeding. It tells about demonstrative behavior, marriage ceremonies of birds, and their tournament fights. The advantages of different types of marital relationships, the age composition of married couples, illegitimate paternity, and bird hybridization are discussed. The basis of the book's content is the world's scientific ornithological and general biological literature on the problems of reproduction and mating systems of animals. The author is a professional zoologist, Doctor of Biological Sciences. The book is intended for a wide range of readers - those interested in birds, as well as ecologists, biology students and biology teachers in secondary and higher educational institutions.