One key task of an animal’s dietary ecology is the ability to locate food items effectively. To better understand the ecomorphological diversification of bats, we are exploring how traits related to prey detection have been shaped by dietary specialization.
Plants have evolved an outstanding diversity of fruit characteristics to signal ripeness to frugivores and, in turn, frugivores have evolved specialized sensory abilities that allow them to locate ripe fruits. The ecological interactions between fruiting plants and fruit-eating bats are crucial to the maintenance and regeneration of tropical ecosystems worldwide. 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. We are currently investigating the coevolution between fruit scents and the olfactory ability and behavioral preferences of fruit-eating bats. This work integrates 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 of two ecologically important and mutualistic groups of tropical plants and animals (Piper plants and Carollia bats). These data will allow us to elucidate whether mutualism has imposed selective pressures on plant and frugivore traits, or if their diversity is best explained by phylogeny. Using novel comparative and experimental approaches, we will link the patterns of diversity in: (1) mutualism strength, (2) fruit scent chemical composition, (3) bat olfactory receptor subgenomes, and (4) bat behavioral 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.
This work is funded by NSF award 1456375
The evolution of morphological differences in the sensory system can open new ecological niches and allow resource partitioning in bats. Neotropical leaf-nosed bats (Phyllostomidae) are one of the most ecologically diverse groups of mammals. They have a wide range of diets, foraging strategies and extreme morphological variation in their sensory structures (i.e. nose leaves and ears). To date, there have been few broad comparative analyses focusing on how morphological differences of the sensory system evolve, and how they functionally affect echolocation parameters in foraging bats. This is a significant knowledge gap because morphological differences can affect fitness via their effect on prey capture performance. We are focusing on animalivorous phyllostomids to address several important questions about sensory evolution, including, how does the morphological diversity of external sensory structures map onto ecological diversity? and, how does behavior modulate the performance of sensory structures? This research, led by Ph.D. student Leith Miller, integrates experimental approaches on free-ranging bats with cutting-edge lab tools to image and model morphology.