Army-ant following in Neotropical birds: A review and prospectus

Abstract

Abstract Army-ants (particularly swarm-raiding species Eciton burchellii and Labidus praedator) are keystone predators in Neotropical forests. Hundreds of associated species from diverse taxa depend on them for survival, the most conspicuous of which are the ant-following birds. These birds forage on cryptic arthropods and vertebrates as they attempt to escape raiding army-ants. Despite capturing the attention of tropical biologists for centuries, research on ant-following birds has been largely limited to natural history observations until more recently. Here, we argue that this complex system provides unique and underappreciated opportunities for testing hypotheses in 5 main areas of interest: (1) competitive interactions among attendant birds, (2) cognitive and behavioral adaptations for locating swarms, (3) evolution of ant-following behavior, (4) biogeography of ant-following behavior, and (5) conservation of ant-following birds. For each research area, we review the current state of knowledge and make suggestions for fruitful research avenues that we believe will help address important questions in the fields of ecology, evolution, and behavior.