The paper by Eugene W. Schupp explores the concept of disperser effectiveness, which is the contribution a disperser makes to the future reproduction of a plant. The effectiveness of seed dispersal is divided into two main components: quantity and quality. Quantity refers to the number of seeds dispersed and is influenced by the number of visits made by the disperser and the number of seeds dispersed per visit. Quality refers to the probability that a dispersed seed will survive and become an adult, and it is influenced by the quality of treatment the seed receives in the mouth and gut, as well as the quality of seed deposition. The paper reviews how disperser behavior, morphology, and physiology can affect these components and presents preliminary analyses of their relationships. The author emphasizes the importance of incorporating thorough analyses of plant demography into seed dispersal studies to better understand the ecological and evolutionary consequences of seed dispersal by animals.The paper by Eugene W. Schupp explores the concept of disperser effectiveness, which is the contribution a disperser makes to the future reproduction of a plant. The effectiveness of seed dispersal is divided into two main components: quantity and quality. Quantity refers to the number of seeds dispersed and is influenced by the number of visits made by the disperser and the number of seeds dispersed per visit. Quality refers to the probability that a dispersed seed will survive and become an adult, and it is influenced by the quality of treatment the seed receives in the mouth and gut, as well as the quality of seed deposition. The paper reviews how disperser behavior, morphology, and physiology can affect these components and presents preliminary analyses of their relationships. The author emphasizes the importance of incorporating thorough analyses of plant demography into seed dispersal studies to better understand the ecological and evolutionary consequences of seed dispersal by animals.