Interactions between nutrients and fruit secondary metabolites shape bat foraging behavior and protein absorption

(Uploaded by Plazi for the Bat Literature Project) Frugivore foraging behavior is largely influenced by two key groups of chemical traits: nutrients and secondary metabolites. Many secondary metabolites function in plant defense, but their consumption can negatively impact both mutualistic and antagonistic frugivores, often due to toxic properties of the metabolites or through nutrient absorption interference. Frugivores are assumed to maximize nutrient acquisition while avoiding or minimizing toxic metabolite intake, but the relative roles of co-occurring nutrients and secondary metabolites in foraging behavior are not well understood. Here, we used a neotropical fruit bat to investigate the interactive effects of nutrients and a broadly bioactive fruit secondary metabolite, piperine, on two essential processes in nutrient acquisition, namely foraging behavior and nutrient absorption. Through the manipulation of nutrient and piperine concentrations in artificial diets, we showed that captive fruit bats prioritize nutrient concentrations regardless of the levels of piperine, even though piperine is a strong deterrent on its own. Furthermore, our findings reveal that while piperine has no detectable influence on total sugar absorption, it reduces protein absorption, which is a crucial and limited nutrient in the frugivore diet. Overall, our results demonstrate the importance of considering the interaction between co-occurring chemical traits in fruit pulp to better understand frugivore foraging and physiology.