Meeting Abstract
Animals exhibit a diverse array of visual and vocal courtship behaviors that vary across taxa and individuals. This study explores the role that male-male competition and individual quality play in shaping free-living male Dark-eyed Junco (Junco hyemalis) courtship. Variation in competition may directly affect the cost of courtship displays, where increased displays may recruit more competitors to the area. However, the effect of competition on courtship success likely depends on male quality, with low-quality males standing at a greater risk of loosing a potential mate than high-quality males. High apparent competition was simulated by repeatedly broadcasting male conspecific song in the focal male’s territory, whereas low competition males were left undisturbed. Juncos from both treatments were then exposed to a live female conspecific to measure their courtship behavior. Males from the high-competition treatment approached the female significantly closer than low-competition males. The effect of the competition treatment on courtship behavior depended on male quality – larger males displayed their tail ornaments more than smaller males in high competition, while in low competition size and tail spread were not related. These findings show that male courtship is a plastic behavior that is modified in response to a changing social environment. Furthermore, individual variation in male quality affects how individuals court in alternate social environments. This interaction between quality and social environment on behavior highlights the importance of taking into account individual differences in ecological and evolutionary study of behavior.
