Synergistic selection regimens drive the evolution of display complexity in birds of paradise

1. Integrated visual displays that combine gesture with color are nearly ubiquitous in the animal world, where they evolve in response to sexual selection for their role in courtship and competition. However, few studies examine how multiple selection regimens shape each component of these complex phenotypes on a macroevolutionary scale. 2. Here we study this issue by assessing how both sexual and ecological selection work together to influence visual display complexity in the birds of paradise. 3. We first find that sexual dichromatism is highest in lekking species, which undergo more intense sexual selection by female choice than non-lekking species. Meanwhile, species in which males directly compete with one another at communal display courts have more carotenoid-based ornaments and fewer melanin ornaments. 4. Meanwhile, display habitat influences gestural complexity. Species that dance in the cluttered understory have more complex dances than canopy-displaying species. 5. Taken toge...