Spatiotemporal variation in the diet of Hooded Berryeater ( Carpornis cucullata ) in the southernmost section of the Atlantic Forest ecoregion

The endemic Hooded Berryeater (<em>Carpornis cucullata</em>) is an important seed disperser in the Atlantic Forest which is arguably a critical player for endemic large-seeded trees to cope with climate change, yet the diet and its spatiotemporal variations remain poorly understood. Here we compiled a comprehensive list of plant species consumed by this bird across its entire range, compared the diversity of plants consumed in two areas of southern Brazil, and assessed the temporal variation in frugivory. Our compilation resulted in 111 plant species on its diet, distributed in 39 families. In 1098 hours of sampling, we identified 53 species consumed in southern Brazil. At the southernmost of its range, the Hooded Berryeater consumes and disperses seeds of 47.7% of its known diet, most of them being trees endemic to the Atlantic Forest. Despite high temporal variation in plant consumption, the bird remained consistently frugivorous year-round, with minimal arthropod consumption at both sites. Fruit consumption peaked during summer and spring but at least five species were consumed during Winter in each area, underscoring its year-round importance for seed dispersal. The high diversity of plants whose fruits are consumed by the Hooded Berryeater suggests it is a keystone seed disperser in the southern portion of Atlantic Forest and that it may have an important role in helping endemic plants cope with climate change by tracking suitable habitats. Furthermore, our study shows that the levels of diversity and interaction complexity of the Atlantic Forest are retained in latitudes as high as 32° South.