Toucans (Ramphastos ambiguus) facilitate resilience against seed dispersal limitation to a large‐seeded tree (Virola surinamensis) in a human‐modified landscape |
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| Authors: | Juan I. Moreira Pablo Riba‐Hernández Jorge A. Lobo |
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| Affiliation: | 1. Proyecto Carey, Península de Osa, Costa Rica, Puntarenas, San José, Costa Rica;2. Escuela de Biología, Universidad de Costa Rica, San Pedro, Costa Rica |
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| Abstract: | Large‐seeded plants may suffer seed dispersal limitation in human‐modified landscapes if seed dispersers are absent or unable to disperse their seeds. We investigated dispersal limitation for the large‐seeded tree Virola surinamensis in a human‐modified landscape in southern Costa Rica. During two fruiting seasons, we monitored crop size, seed removal rates, the number of fruiting conspecifics within 100 m, and feeding visitation rates by frugivores at trees located in high and low forest disturbance conditions. Seed removal rates and the total number of seeds removed were high regardless of the disturbance level, but these parameters increased with tree crop size and decreased with the number of fruiting V. surinamensis trees within a 100 m radius. Trees at low disturbance levels were more likely to be visited by seed dispersers. Black mandibled toucans (Ramphastos ambiguus) and spider monkeys (Ateles geoffroyi) were the most important seed dispersers, based on visitation patterns and seed removal rates. Spider monkey feeding visits were more frequent at high disturbance levels, but the monkeys preferentially visited isolated trees with large yields and surrounded by a low number of fruiting Virola trees within 100 m. Toucan visitation patterns were not constrained by any of the predictors and they visited trees equally across the landscape. We suggest that isolated and highly fecund Virola trees are an important food resource for spider monkeys in human‐modified landscapes and that toucans can provide resilience against seed dispersal limitations for large‐seeded plants in human‐modified landscapes in the absence of hunting. |
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| Keywords: | Anthropogenic disturbance
Ateles
frugivory hunting Osa Peninsula
endozoochory
seed removal forest fragmentation |
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