Kendeigh Charles S. Parental Care and Its Evolution in Birds

Urbana, IL: University of Illinois press, 1952. — 385 p. — (Illinois Biological Monographs. Volume XXII. Nos. 1-3).The study of bird behavior is of intense interest to a great many people. A few fortunate individuals are able to pursue this study vocationally, but to most it can be no more than a hobby. Bird behavior is complex, varied, and challenging at all seasons of the year. Each season induces some different activity, such as migration, mating, nesting, molting, or flocking. One must go into the out-of-doors to study these activities, but he need not go farther than his backyard to find much of interest and importance. Certain psychological analyses of how and why birds behave as they do and the testing of sense organs, reflexes, and conditioned responses may be done in the laboratory, but it is necessary to study the bird in the field under free, natural conditions to get normal behavior in its full complexity and significance.