Neuroecology and diet selection in phyllostomid bats

For many birds and mammals relative brain and hippocampus volume are positively related to enhanced behavioral flexibility and spatial memory. I tested for correlations between species-specific diet selection and relative brain and hippocampus volumes in the New World leaf-nosed bats (Phyllostomidae). To this end, I classified each of 53 species from this ecologically diverse family as one of the following: (i) predatory, (ii) omnivorous, (iii) frugivorous, or (iv) nectivorous. Species-level analyses and the comparative method (i.e. phylogenetically independent contrasts) revealed that relative hippocampus volume was greater in predatory species than in frugivorous and nectivorous species and that relative brain size was greater in frugivorous species than in predatory species. As previously reported, specialized frugivory appears to be associated with increased relative brain volume suggesting these two traits evolve together. I suggest some plausible functional explanations for variation in hippocampus volume in light of our current understanding of the acquisition of spatial information and its use by echolocating bats.