Unraveling the leaf-dropping behavior behind bat folivory: do bats use biological control against roost parasites?

Abstract

Abstract Folivory in bats, the behavior of chewing bites of leaves to extract the liquid portion and discard the fiber as oral pellets, is seen as a strategy that might provide vitamins, micronutrients and proteins not always available in fruits, and even secondary metabolites (hormonal precursors) that stimulate/inhibit reproductive processes. While examining chewed leaves, we noticed an important amount of completely intact leaves below the roosts of Artibeus amplus and Artibeus lituratus, and decided to systematically quantify them during a year. We recovered 639 intact leaves from six plant species and found that both species are constantly feeding on leaves, but invariably leaving 26–78% of these intact, dropping them on the floor just below their roosting sites. These large proportions of dropped, intact leaves suggest a completely different, novel, non-nutritional use by bats. Several studies in birds have revealed that fresh leaves are effectively used in nests to control diverse organisms that include blood suckling ectoparasites, protozoans, fungus and bacteria. We report for the first time this biological control behavior performed by bats by selecting, bringing and dropping intact leaves below their roosting sites. The chemical properties of the leaves need to be investigated to reveal those active components against specific pathogens.