Specialized Seed Dispersal in Epiphytic Cacti and Convergence with Mistletoes |
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Authors: | André de C. Guaraldo Bruna de O. Boeni Marco A. Pizo |
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Affiliation: | 1. Departamento de Zoologia, Programa de Pós‐Gradua??o em Ecologia, Laboratório de Ecologia e Conserva??o de Aves, IB, Universidade de Brasília, , 70910‐900 Brasília – DF, Brazil;2. Departamento de Botanica, Programa de Pós‐Gradua??o em Botanica, Universidade Federal do Rio Grande do Sul, Instituto de Biociências, , 91501‐970 Porto Alegre – RS, Brazil;3. Departamento de Zoologia, Universidade Estadual Paulista, , 13506‐900 Rio Claro – SP, Brazil |
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Abstract: | Mistletoes represent the best example of specialization in seed dispersal, with a reduced assemblage of dispersal agents. Specific dispersal requirements mediated by the specificity of seed deposition site have apparently led to the evolution of such close relationships between mistletoes and certain frugivores. Here, we provide evidences for another case of specialization involving epiphytic cacti in the genus Rhipsalis, and small Neotropical passerines Euphonia spp., which also act as the main seed dispersers of mistletoes in the family Viscaceae. With field observations, literature search, and observations on captive birds, we demonstrated that Rhipsalis have specific establishment requirements, and euphonias are the most effective dispersers of Rhipsalis seeds in both quantitative and qualitative aspects, potentially depositing seeds onto branches of host plants. We interpret the similar dispersal systems of Rhipsalis and Viscaceae mistletoes, which involve the same dispersal agents, similar fruit morphologies, and fruit chemistry as convergent adaptive strategies that enable seeds of both groups to reach adequate microsites for establishment in host branches. |
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Keywords: | Atlantic Forest Brazil convergent evolution
Euphonia
frugivory
Rhipsalis
seed germination |
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