Macroevolução e macroecologia de atributos fenotípicos reprodutivos em Pipridae

Abstract

The family Pipridae, or manakins, as they are popularly known, are a Neotropical family of birds that exhibit a great diversity of phenotypes, especially in males, which commonly display bright coloration and perform elaborate courtship dances for females. These phenotypes are present in both young and adult males and are refined and modified throughout an individuals' life through delayed plumage maturation and dance practices until they assume the stereotypical phenotypes known for each species. The overall objective of this study is to understand the processes associated with the evolution of complex phenotypic traits related to reproduction in the Pipridae family. For this, regarding adult males, we conducted an extensive review of morphological and behavioral traits in the family, characterizing each behavioral unit as unique elements, estimating the probable moments of their emergence in the phylogeny and ancestral states, as well as the phylogenetic signal associated with the traits, and the evolutionary models that best describe their evolution. Additionally, we evaluated whether and to what degree phenotypic similarity is influenced by evolutionary history, climate, and geographical overlap among species. Finally, regarding young males, we conducted a review of plumage development in the family and applied a qualitative approach to evaluate possible hypotheses about the function and constraints guiding the evolution of delayed plumage maturation. We found an extensive richness of 94 courtship elements, of which 36% represent autapomorphies, and most show a strong phylogenetic signal, a pattern that also applies to morphological traits, along with the prevalence of evolutionary models compatible with Brownian Motion and/or trait conservatism. Furthermore, we found ancestrality to be the main driver of phenotypic similarity among species. At last, regarding delayed plumage maturation, we found little evidence that the plumage development in male manakins is subject to physiological and environmental constraints, and the most likely hypothesis for plumage maturation occurring at different stages in many species is related to a social status-signaling function. Our results suggest that most traits presented by adult males evolved through the interaction between processes of phylogenetic inertia and selective forces, with this interaction potentially varying according to the degree of importance of the courtship behavior for female choice, and that social interactions for the establishment of hierarchies and territories can affect the physiology of young males. Thus, we observe that even in a well-studied taxon, where a clearer understanding of the acting evolutionary processes is assumed, such as the role of sexual selection for manakins, it is still possible to find surprises and idiosyncrasies that make the scientific understanding of this subject a complex task.