RT Journal Article T1 Flower visitor networks: Reduced reproductive success driven by antagonists in a hummingbird‐pollinated species A1 Gélvez Zúñiga, Irene A1 Costa, Fernanda V. A1 López Teixido, Alberto A1 Ashworth, Lorena A1 Aguilar, Ramiro A1 Fernandes, G. Wilson AB Flower–animal interactions encompass a continuum of mutualistic to antagonistic behaviors. Although the importance of pollinators in interaction networks has been widely reported, the role of floral antagonists remains overlooked. In Collaea cipoensis, an endemic shrub from southeastern Brazil, we modeled an individual-based network assessing the flower visitors' functional behavior and tested if plant centrality increases fitness. Centrality indicates how well-connected a given plant is with the rest of the conspecifics through shared flower visitors. Specifically, we tested if flower visitor interactions are amplified by many-flowered individuals, and whether the relationship between centrality and plant fitness encompasses the effects of mutualists or antagonists. Subsequently, we quantified each visiting species' effectiveness. Antagonistic interactions were the most frequent in the network (97% of visits), primarily conducted by the nectar-robbing bee Trigona spinipes (66%), which was also the most central species and detrimental antagonist. The hummingbirds Colibri serrirostris and Eupatomena macroura were the most efficient pollinators, with a high contribution to the quantity—floral visitation—and the quality—viable seeds—components, respectively. Many-flowered plants showed greater centrality, which boosted the plant's cohesion in the network and increased flower visitation. Accordingly, many-flowered plants were better connected, mainly due to antagonistic visitors. Thus, centrality increases were not positively translated into more reproductive success. Our results reinforce the dynamic scenarios of flower–animal interactions, with consequences to plant reproductive ecology. We highlight the importance of incorporating distinct types of interactions to unveil the complexity of interacting systems, that when not explored, hide potential evolutionary consequences for plant reproductive success. PB Wiley SN 0006-3606 YR 2024 FD 2024 LK https://hdl.handle.net/20.500.14352/118053 UL https://hdl.handle.net/20.500.14352/118053 LA eng NO Gélvez-Zúñiga, I., Costa, F. V., Teixido, A. L., Ashworth, L., Aguilar, R., & Fernandes, G. W. (2024). Flower visitor networks: Reduced reproductive success driven by antagonists in a hummingbird-pollinated species. Biotropica, 56, e13342. https://doi.org/10.1111/btp.13342 NO IGZ received a scholarship from PEC-PG/UFMG. The present study was funded by ComCerrado, CAPES, FAPEMIG, CNPq/PELD, and Anglo American Brasil. NO Rede ComCerrado NO Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brasil) NO Fundação de Amparo à Pesquisa do Estado de Minas Gerais (Brasil) NO Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil) DS Docta Complutense RD 31 dic 2025