Directed seed dispersal towards areas with low conspecific tree density by a scatter‐hoarding rodent |
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Authors: | Ben T Hirsch Roland Kays Verónica E Pereira Patrick A Jansen |
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Institution: | 1. Smithsonian Tropical Research Institute (STRI), , Balboa, Panama;2. School of Environment and Natural Resources, Ohio State University, , Columbus, OH, 43210 USA;3. Nature Research Center, North Carolina Museum of Natural Sciences, , Raleigh, NC, 27601 USA;4. Fisheries, Wildlife & Conservation Program, North Carolina State University, , NC, 27695 USA;5. Department of Environmental Sciences, Wageningen University, , 6700 AA, Wageningen, the Netherlands;6. Centre for Ecological and Evolutionary Studies, University of Groningen, , 9700 CC, Groningen, the Netherlands |
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Abstract: | Scatter‐hoarding animals spread out cached seeds to reduce density‐dependent theft of their food reserves. This behaviour could lead to directed dispersal into areas with lower densities of conspecific trees, where seed and seedling survival are higher, and could profoundly affect the spatial structure of plant communities. We tested this hypothesis with Central American agoutis and Astrocaryum standleyanum palm seeds on Barro Colorado Island, Panama. We radio‐tracked seeds as they were cached and re‐cached by agoutis, calculated the density of adult Astrocaryum trees surrounding each cache, and tested whether the observed number of trees around seed caches declined more than expected under random dispersal. Seedling establishment success was negatively dependent on seed density, and agoutis carried seeds towards locations with lower conspecific tree densities, thus facilitating the escape of seeds from natural enemies. This behaviour may be a widespread mechanism leading to highly effective seed dispersal by scatter‐hoarding animals. |
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Keywords: | Astrocaryum agouti Barro Colorado Island directed dispersal density dependence Dasyprocta punctata secondary seed dispersal |
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