Social and environmental cues drive the intra-population variation in courtship behavior of a neotropical lekking bird

Sexual selection predicts evolution of secondary sexual traits favoring mating. Here, we address the within population variation in courtship display behavior among male White-throated Manakins, Corapipo gutturalis, from Central Amazonia. We repeatedly quantified the courtship display elements used by 16 males over multiple days and specifically tested whether male presence and displays at courts could be explained by variation in environmental conditions (forest shade with small sunny gaps, large sunny gaps, and cloudy), male age (juvenile or adult), or yet the social context (other males and female visits) during displays. Our results show that total male presence and time displaying varied with the total number of other males and female visits at the court. In addition, the type of courtship elements used in displays (assessed by principal component analysis) also varied with the presence of both females and other males on the court. Male age, however, did not influence male activity. Overall, the social context at the court was the strongest predictor of within-population variations in male courtship display, whereas light conditions only affected display duration. Variation in display repertoire with female presence might reflect variation in female preferences. In addition, similar displays among males of different age classes suggest a competitive, rather than cooperative lek system of White-throated Manakins in Central Amazonia.