Diet composition of reintroduced Red-and-Green Macaws (Ara chloropterus) reflects gradual adaptation to life in the wild

Over the last two centuries, the Red-and-Green Macaw (Ara chloropterus) has become locally extinct in Argentina. In an attempt to restore its key ecosystem functions as both disperser and regulator of large-seeded plants, a reintroduction project was initiated at the Iberá National Park in northeastern Argentina. The ability of released individuals to find food is crucial, especially when working with captive-bred animals, as long-term establishment of a self-sustaining population depends on their short-term ability to exploit wild food sources. Monitoring of feeding habits is usually conducted through behavioral observation, but in recent years DNA metabarcoding has emerged as an alternative for obtaining highly resolved data on diet composition. In this study, we use a combination of both techniques to characterize the breadth and composition of the reintroduced macaws’ diet. In addition, we compare the efficiency of both observational and molecular techniques to assess diet compositi...