Effects of habitat and fruit scent on the interactions between short-tailed fruit bats andPiperplants

Abstract

AbstractPiperis a mega-diverse genus of pioneer plants that contributes to the maintenance and regeneration of tropical forests. With deforestation and climate change threatening forest ecosystems, understanding the mutualism betweenPiperand its seed dispersers becomes especially important. In the Neotropics,Carolliabats use olfaction to forage forPiperfruit and are a main disperser ofPiperseeds via consumption and subsequent defecation during flight. In return,Piperfruits provide essential nutrients forCarolliayear-round. There is evidence that the types and diversity ofPiperfrugivores are influenced by the primary habitat of differentPiperspecies (forest, gap), with forestPiperdepending more on bats for seed dispersal; however, this pattern has not been tested broadly. We aimed to characterize and compare the interactions betweenCarolliaandPiperacross forested and gap habitats, and further investigate whether differences in fruit traits relevant to bat foraging (i.e., scent) could underlie differences inCarollia-Piperinteractions. We collected nightly acoustic ultrasonic recordings and 24h camera trap data in La Selva, Costa Rica across 12 species ofPiper(6 forest, 6 gap) and integrated this information with data onCarolliadiet andPiperfruit scent. Merging biomonitoring modalities allowed us to characterize ecological interactions in a hierarchical manner: from general activity and presence of bats, to visitations and inspections of plants, to acquisition and consumption of fruits. We found significant differences inCarollia-Piperinteractions between forested and gap habitats; however, the type of biomonitoring modality (camera trap, acoustics, diet) influenced our ability to detect these differences. ForestPiperwere exclusively visited by bats, whereas gapPiperhad a more diverse suite of frugivores; the annual diet ofCarollia, however, is dominated by gapPipersince these plants produce fruit year-round. We found evidence that fruit scent composition significantly differs between forest and gapPiper, which highlights the possibility that bats could be using chemical cues to differentially forage for gap versus forestPiper. By integrating studies ofPiperfruit scent, plant visitation patterns, andCarolliadiet composition, we paint a clearer picture of the ecological interactions betweenPiperandCarollia, and plant-animal mutualisms more generally.