This project will investigate the joint evolution of the olfactory ability and behavioral preferences of fruit-eating bats and the scents of the fruits that they eat. Plants have evolved an outstanding diversity of fruit characteristics to signal ripeness and, in turn, fruit-eaters have evolved specialized sensory abilities that allow them to locate ripe fruits. If and how bats have shaped the evolution of fruits traits, and how bat sensory abilities have evolved to detect fruit signals, however, remains poorly understood. Because the ecological interactions between fruiting plants and fruit-eating bats are crucial to the maintenance and regeneration of tropical ecosystems worldwide, this work will have important implications in the management of tropical forests. Results from this project will be incorporated into an exhibit at the Burke Museum of Natural History and Culture and traveling study kits for elementary school students in Seattle and Costa Rica. The project will also provide training for a diverse group of undergraduates, graduate students, one postdoctoral researcher, and a Costa Rican graduate student.
The project will focus on a relatively unexplored yet crucial aspect of plant-animal mutualisms: volatile chemical communication between plants and vertebrate frugivores. It will integrate advanced tools from analytical chemistry, molecular genetics, and behavioral ecology to collect unprecedented data on diet, fruit volatile molecules, bat olfactory genes and behavioral preferences for two ecologically important groups of tropical plants and animals (Piper plants and Carollia bats). This work will test whether mutualism has imposed selective pressures on plant and frugivore traits, or if their diversity is best explained by phylogeny. Novel comparative and experimental approaches will link the patterns of diversity in: (1) mutualism strength, (2) fruit scent chemical composition, (3) bat olfactory receptor subgenomes, and (4) bat scent preferences. By relating plant chemical signals to the olfactory subgenome and behavioral responses of frugivores, this research will jumpstart the integration of genomic and behavioral applications in evolutionary ecology, and enable future research on the functional chemical ecology of complex systems.
