Fruit Intake and Energy Budgets of Frugivorous Bats

Abstract

Paleotropical fruit bats (Pteropodidae) ingest up to 2.5 times their body mass in fruits nightly. On a mass-specific basis, this is about double the amount reported for neotropical fruit bats (Phyllostomidae). By manipulating the energy and protein contents of their diets, I found that the pteropodids' high fruit intakes are determined by the protein content of the fruits they exploit. Pteropodids appear to be obliged to overingest energy in order to obtain sufficient protein. Phyllostomid fruit bats may escape this protein constraint by supplementing their diets with insects, thus increasing the overall protein content of the diet. Differing abilities to supplement their diets may result in important differences in how pteropodid and phyllostomid bats nutritionally evaluate fruits, regulate their intakes, and function as seed dispersers.