The Behavioral Systems Cluster supports research on the development, function, mechanisms, and evolutionary history of behavior, with emphasis on a vertically integrated understanding of the behavioral phenotype in nature. To foster this integrative goal, the Cluster specifically encourages projects that seek to understand how combinations of neural, hormonal, physiological, and developmental mechanisms act synergistically as a system from which behavior emerges. Laboratory work or the study of animals in captivity is encouraged, to the extent that it contributes to the understanding of behavior in natural systems.