Abstract
A variety of behavioral patterns occur during the avian reproductive cycle. Characteristic patterns of behavior are seen in adult birds during the periods of courtship, nest building, egg laying, incubation and care of nestlings. These periods also are distinguishable by definite changes in the internal physiology of the birds. Knowledge of the effects of the physiological events on the behavioral patterns as well as the role of external factors are important to the understanding of the basis of parental behavior. An example of the complexity of the interrelationships is seen in the fact that female Ring Doves (Streptopelia risoria) can be induced to undergo oviduct growth, ovulation, and incubation behavior by association with a mate. This effect can be further augmented by the presence of nest building materials.