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

Abstract

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