The implications of food hardness for diet in bats

Abstract

Summary: Neotropical bat communities are characterized by a broad species diversity, which can be achieved and maintained only through partitioning of the available resources. Here patterns of trophic resource utilization within a single neotropical savanna bat community are investigated. Moreover, the physical properties of food items (i.e. hardness), its variation with food size, and whether food hardness differs between items consumed by the bats in this community are investigated experimentally. The results show that food hardness increases with the size of the food item, and that distinct differences exist in the amount of force needed to crush different food items (beetles vs other insects vs fruits). Using previously published data on bite forces from species in the same community it is explored whether food hardness may play a role in shaping the diets of the bats in the community. The combined data on bite forces and food hardness indicate that food hardness can both directly and indirectly limit dietary diversity in bats. The results also indicate that dietary specialization may potentially result in a decrease in trophic breadth for some species through its effect on bite performance.