Use of food resources by sympatric Manakins in the Atlantic Forest of southeastern Brazil

The tropics have an enormous diversity of birds, providing models for studies of the ecological interactions between birds and plants. This present study investigated potential resource partitioning among the Red-headed Manakin (Ceratopipra rubrocapilla), White-crowned Manakin (Dixiphia pipra) and White-bearded Manakin (Manacus manacus) in the lowland forest of the União Biological Reserve, a priority area for bird conservation in Rio de Janeiro state and the Americas. We obtained fecal samples from captured and ringed individuals. Fruit dominated the diets of all three species [C. rubrocapilla: 97% of samples (n=39); D. pipra: 87% (n=115); M. manacus: 91% (n=44)] while arthropods were less important (18%, 37%, 32%, respectively), corroborating the potential importance of these birds for seed dispersal. Fruit of 12 families were consumed [C. rubrocapilla (5), D. pipra (5), and M. manacus (9)], but only the Melastomataceae and Rubiaceae were common to all three birds. The Melastomataceae was the most consumed, with four morphotypes, two of which were consumed by all three birds: Miconia calvescens (C. rubrocapilla: 36%, D. pipra: 4%, M. manacus: 9%) and Miconia sp. (38%, 49%, 57%, respectively). Ceratopipra rubrocapilla consumed one exclusive Miconia morphotype a nd differed from the other birds in its reduced consumption of arthropods and high rate of consumption of M. calvescens, while D. pipra consumed more Miconia sp. than M. calvescens. Our results indicate that M. manacus consumes arthropods more frequently in the study area than at other sites, and was the most generalist of the three manakins monitored in this study.