Dancers in fine feathers: the evolution of gestural display organization in lekking birds

Courtship displays are remarkably complex in birds, especially in species under strong sexual selection. An overlooked aspect is the organization of gestural elements, where more temporarily coordinated and predictable movements may improve information transfer. We tested if display organization is influenced by the number of gestural elements in the displays, lek spatial structure, body size and habitat. We built a dataset of lekking bird gestural displays for males and females described in the literature and video recordings from online platforms. From recordings, we quantified display organization using information theory measures. For both sexes, species with larger repertoires showed more organized displays, indicating that increased complexity does not constrain syntax. Sex differences in display organization were higher in species with lower sexual size dimorphism, suggesting a trade-off between traits important for communication. By highlighting display organization of gestural displays, we offer an extensive investigation of an overlooked yet crucial aspect of bird courtship.