Digest: Evolution of specialized ant-following behavior across Neotropical birds

What factors explain the evolution of specialization in the ant-following behavior across Neotropical birds? By employing ancestral reconstructions and studying the morphofunctional space, Sweet et al. (2025) show that phylogenetic history, rather than functional traits, is the strongest predictor of ant-following specialization. Ant-following behavior showed several reversions but a strong tendency for transitions from facultative to obligate states. This study uncovers the relevance of shared ancestry and niche conservatism in governing the evolution of behavioral specialization.