Abstract
Environmental and physiological control of incubation behavior in wild and domesticated birds has been under investigation for the past thirty-five years. Most of the early literature deals with the non-passerines, specifically doves, pigeons and fowl. However, recent work has involved the order Passeriformes. The Redwinged Blackbird (Agelaius phoeniceus) of this order is the subject of the present investigation. Changes in prolactin quantities of the pituitary at various stages in the reproductive cycle are the prime areas of concern. | Most of the previous experiments have involved domesticated birds or birds caught in the wild and then caged under simulated, natural, environmental conditions. While it is advantageous to be able to control the variables of the environment, certain naturally occurring uncontrollable variables are known to influence the internal environment in many instances, and are responsible for normal behavior in an animal. Hence, an accurate description of hormonal influence on behavior requires monitoring endocrine correlates to behavior in natural populations.