Discipline: Biological Sciences
Subcategory: Plant Research
Kimberly Hamilton - CSU Stanislaus
Co-Author(s): Erin Kuprewicz, Smithsonian Institution, Washington, D.C.
Granivorous mammals are abundant within some lowland tropical forests and can have profound effects upon local plant communities. Seed detection is an important yet understudied aspect of animal behavior. This study examines the potential mechanisms of seed detection by ignorant seed predators — predators that have no previous knowledge of a buried seeds location. Using artificial seedlings and Iriartea deltoidea seeds, we explored how Central American agoutis (Dasyprocta punctata) and collared peccaries (Pecari tajacu) locate underground seeds — we predicted that animals might use a combination of visual and olfactory cues. We set out 224 artificial seedlings (visual cues) with and without seeds (scent cues) within and outside semi-permeable exclosures in the primary forest of La Selva Biological Station, Costa Rica. Exclosures allowed agouti entrance, excluding peccaries whereas seedlings and seeds outside of exclosures were accessible to all mammals. We tracked seed and seedling mortality of six different treatment types: mature seedling/ seed; mature seedling/no seed; young seedling/seed; young seedling/no seed; hoard; and sham burial. We found that there was not any agouti activity after thirty-five days and only a small amount of peccary activity after the same amount of time — fourteen interactions with seeds and seedlings. We found no significant difference between peccaries foraging on seeds with and without artificial seedlings, indicating that peccaries use a combination of visual and olfactory cues to detect hidden seeds. This study shows that peccaries have a larger negative effect on seedling survival compared to agoutis and this may scale up to affect forest community dynamics.
Funder Acknowledgement(s): National Science Foundation, Organization for Tropical Sciences
Faculty Advisor: Erin Kuprewicz,