Diet composition of the Red-billed curassow (Crax blumenbachii) and its role as seed disperser in the Atlantic Forest: conservation insights

Introduction: Forest fragmentation and defaunation are major drivers of biodiversity loss in the Atlantic Forest of Brazil, where 70–90% of tree species depend on animal-mediated seed dispersal. Reintroduction of large frugivores, such as cracids, is being used to restore species populations and lost ecological functions. However, basic information on the diet and dispersal performance of reintroduced populations is still scarce, which limits restoration planning. Objectives: We assessed, for the first time, the diet of a reintroduced population of Crax blumenbachii, one of the last remaining large-bodied frugivorous birds in this biome. Methods: Fecal samples from a reintroduced population were analyzed between 2021 and 2024 in a 753 ha forest fragment in Minas Gerais. Seeds species were identified and germination tests conducted, and then consumed species were classified according to seed and fruit traits. Potential dispersal distance was estimated for the most-consumed seed species. Results: We found a diverse diet, including 80 plant species, mainly fleshy-fruited native trees and shrubs, but also cultivated/exotic species. Seasonal analyses showed that the set of consumed species was broader in the dry season, indicating dietary flexibility. Defecated seeds showed species-specific germination responses, with some reaching high rates (up to 73%), while others failed to germinate. We also found that C. blumenbachii disperses seeds over long distances, with most seeds deposited 300–500 m from the ingestion point. Conclusion: Our results suggest that restoring populations of C. blumenbachii can significantly enhance plant recruitment for multiple fleshy-fruited species, reinforcing its functional importance in efforts to recover Atlantic Forest fragments.