Potential roles of fish, birds, and water in swamp privet (Forestiera acuminata) seed dispersal
Forestiera acuminata (swamp privet) is a common wetland shrub/small tree native to the southeastern United States. We examined several possible dispersal avenues for the plant. We tested germination of seeds exposed to various treatments, including passage through Ictalurus punctatus (Channel Catfi sh) guts, and conducted other tests and observations to infer seed-dispersal pathways. Channel Catfi sh consumed swamp privet drupes and defecated viable seeds, confi rming that they are seed dispersers. Bombycilla cedrorum (Cedar Waxwings) ate the carbohydrate-rich drupes, and we predict that they disperse the seeds. We also inferred passive seed dispersal by water. Diverse dispersal pathways may allow for effective seed dispersal under a wide range of environmental conditions. Growing in wetlands and riparian areas, the plant experiences extreme annual variation in hydrologic conditions, which should infl uence the importance of the various dispersal pathways among years.