The American persimmon (Diospyros virginiana) has been viewed as a potential anachronistic fruit that lost its mammalian seed dispersers during the late Pleistocene extinction event. In this study, we examined the extant mammals that naturally feed on persimmons and tested their potential as effective seed dispersers. During the fruiting season, camera traps were placed at replicated persimmon trees to determine the visitation rates of mammals. Individual ripe fruits were also monitored to determine their consumption rates. In separate field experiments, persimmons were fed and their seeds collected from scat (or collected from wild scat) from a variety of extant mammals, including some that functioned as Pleistocene ecological analogs. Seeds collected from these animals were planted in a field experiment, and the survivorship and growth of seedlings followed over one season.
Results/Conclusions
We found that white-tailed deer (Odocoileus virginianus) made up the vast majority (over 90%) of individuals feeding on persimmons. Over 75% of persimmons were consumed, while the remainder rotted under the parent tree. Of the mammals directly tested for potential dispersal, the coyote (Canis latrans), raccoon (Procyon lotor), and Asian elephant (Elephas maximus) had seeds that survived gut passage. Other animals tested either failed to consume the seeds or had no seeds survive gut passage. Seeds that had passed through an animal had the same sprouting rates as those that did not. However, growth rates and final mass values were generally higher in those that had been consumed by an animal. Our results indicate that both living and extinct mammals were potentially effective seed dispersers for the American persimmon, although most fruits today appear to be consumed by non-effective mammals (i.e. white-tailed deer). We found no evidence for specialized co-evolution between persimmons and extinct Pleistocene mammals, but suggest that the anthropogenic changes in North American mammal communities could be reducing seed dispersal today.