Although pollen is included in the diet of vertebrates and invertebrates, and extraction efficiency of its contents has been estimated for several flower visitors, the relationship between feeding habits and pollen digestion efficiency has not been carefully studied. We compared the efficiency with which four species of New World bats with different feeding habits extracted the contents of different types of pollen, and we tested the hypothesis that flower-visiting bats have higher extraction efficiencies than fruit-eating bats. We gave doses of different types of pollen to two nectarivorous (Anoura geoffroyi Leptonycteris curasoae) and two frugivorous (Artibeus jamaicensis Sturnira lilium) bats and collected their feces at regular intervals. We used pollen from three species of flowers that are associated with bat visitation: Pseudobombax ellipticum, Hylocereus undatus and an unidentified species of night-blooming, columnar cactus. In addition to estimating the percentage of empty pollen grains in the fe...