Research Interests:

My research interests lie in the field of plant-animal interactions, integrating the fields of ecology, animal behavior, and evolution. More specifically, I study the interactions of mammals and insects with seeds and young seedlings in tropical forests and how these interactions contribute to forest community dynamics that may be maintained or lost in the Anthropocene.


Current Projects

> Barriers to plant migrations in the Anthropocene

> Project CUE (Clues to Underground Edibles)



Past projects:

> Scatter hoarding of seeds confers survival advantages and disadvantages to large-seeded tropical plants at different life stages

Exp setup for climate change exptsI tested the hypothesis that scatter hoarding by Central American agoutis (Dasyprocta punctata) enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. I followed seeds to germination and determined how terrestrial mammals affect the survival of young seedlings. I simulated agouti caches with seeds from three palms (Astrocaryum alatum, Iriartea deltoidea, Socratea exorrhiza) and one Fabaceae (Dipteryx panamensis); seeds were exposed to invertebrate or vertebrate seed predators for 36-day periods over three years. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis) and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using a novel experimental methodology, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, however tradeoffs in seed survival do exist. Link to PAPER





> Using a comprehensive DNA barcode library to detect novel egg and larval host plant associations in a Cephaloleia rolled-leaf beetle

Bromeliad beetleTo accurately identify immature life stages and uncover novel plant-herbivore interactions, we generated a comprehensive DNA barcode library for a community of rolled-leaf beetles (Coleoptera: Chrysomelidae) in a premontane tropical forest in Costa Rica. The DNA barcode COI accurately identified all beetle species included in the study. Using this DNA barcode library, we identified eggs and larvae of Cephaloleia histrionica Baly with 100% confidence. This new record of C. histrionica is unique in that this species completes its life cycle on a bromeliad, whereas most Cephaloleia species are associated with plants from the order Zingiberales. Link to PAPER





> Mammal abundances and seed traits control the seed dispersal and predation roles of terrestrial mammals in a Costa Rican forest
2_walkers_coloredThe objectives of this study were to determine relative peccary and agouti abundances within a lowland forest in Costa Rica and to assess how these two mammals affect the survival of large seeds that have no defenses (Iriartea deltoidea, Socratea exorrhiza), physical defenses (Astrocaryum alatum, Dipteryx panamensis), or chemical defenses (Mucuna holtonii) against seed predators. Mammal abundances were steady over three years, but peccaries were much more abundant relative to agoutis (up to 6x more abundant). Non-defended and chemically-defended seeds suffered high levels of predation by peccaries whereas agoutis consumed many physically-defended seeds. In peccary-rich forests, seeds protected by hard endocarps are more likely to survive, be hoarded by agoutis, and potentially germinate than unprotected or toxic seeds. Link to PAPER




> Mammal and insect predation of chemically and structurally defended Mucuna holtonii (Fabaceae) seeds in a Costa Rican rain forest

Mucuna_grouping_FINALMucuna holtonii seeds have high concentrations of L-dopa (a toxic amino acid) and a leathery seed coat that act as chemical and physical deterrents (respectively) against seed predators. This study assessed the effectiveness of defenses against vertebrate and invertebrate seed predators within Estación Biológica La Selva, Costa Rica. Collared peccaries consumed most (98.6%) of seeds and were apparently unaffected by L-dopa, probably because these ungulates possess foregut fermentation. The seed coat prevented seed predation by Sericomyrmex amabilis ants. Ants attached all seeds that had opened seed coats. Seeds that had large amounts of endosperm removed by these ants had lower germination success and root + shoot biomass production than seeds that had only small amounts of endosperm removed. Link to PAPER




> Vertebrate fruit removal and ant seed dispersal in the Neotropical ginger Renealmia alpinia (Zingiberaceae)

Renealmia_picsI investigated the alleged mammal seed dispersal syndrome of the ginger Renealmia alpinia using camera traps to monitor fruit removal by mammals. Contrary to previous findings, toucans and aracaris (Ramphastidae) removed most fruits with some fruits also taken by coatis and armadillos. Of fruits that dehisce and fall to the forest floor, ground-dwelling ants remove and disperse many of the seeds. Using a laboratory colony of Ectatomma ruidum ants, I found that R. alpinia seed manipulation by ants increased seed germination success and reduced time to germination. Link to PAPER