First observations of foraging relationship between white-shouldered fire-eye Pyriglena leucoptera (Passeriformes) and Azara’s agouti Dasyprocta azarae (Rodentia)

The white-shouldered fire-eye Pyriglena leucoptera (Vieillot, 1818) is a bird characterized by vivid red eyes and glossy black plumage, inhabiting the Atlantic Forest, ranging from Bahia to Rio Grande do Sul in Brazil, as well as regions of Paraguay and Argentina. Its diet predominantly consists of ground-dwelling invertebrates, and it has a notable foraging behavior, often trailing army ants for sustenance. Recently, we discovered the first observed instance of interaction between P. leucoptera and a medium-sized mammal, the Azara’s agouti Dasyprocta azarae Lichtenstein, 1823. This behavior, where the bird follows the agouti, capitalizing on the insects and invertebrates it exposes as it moves, offers valuable insights into the bird’s ecology and feeding strategy. This unique ecological interaction raises questions about its frequency and the factors influencing such behavior, contributing to our understanding of species interrelationships in this ecosystem and potentially highlighting the bird’s adaptive strategies for foraging and energy optimization.