Comparative Phylogenetic Analyses

Evolution of Social Mating Systems and Nesting Sociality in Birds

This project uses comparative phylogenetic methods to investigate the evolutionary origins of social mating systems and nesting behavior in birds. Focusing on weaverbirds (family Ploceidae)—a diverse passerine radiation known for complex social behavior—we examine how ecological factors have shaped the evolution of polygyny, colonial breeding, and habitat use.

Using a well-resolved species-level phylogeny and ecological trait data, we tested hypotheses about the relationships among mating systems, nesting sociality, habitat preferences, and diet. Our analyses suggest that ancestral weaverbirds were colonial, polygynous birds inhabiting savanna environments and feeding primarily on plant material, while traits such as monogamy, insectivory, and forest-associated habitats evolved later in the lineage.

The results reveal strong associations between mating systems, nesting dispersion, and habitat type, while diet appears less strongly related to social mating strategies. Importantly, our findings challenge the widely held assumption that polygyny evolves primarily in open habitats. Instead, the analyses suggest that changes in social mating systems may drive historical shifts in habitat use across bird lineages.

Ongoing work is expanding these analyses by incorporating additional natural history traits, morphological variables, and continuous environmental data. Using phylogenetic comparative methods such as Phylogenetic Generalized Least Squares (PGLS) and Phylogenetic Generalized Linear Mixed Models (PGLMM), we aim to further explore how ecological and evolutionary processes shape the diversity of reproductive strategies and social systems across birds.