Rousettus madagascariensis (Chiroptera: Pteropodidae) shows a preference for native and commercially unimportant fruits

Flight cage choice experiments carried out over 4 mo demonstrated that a Malagasy fruit bat, Rousettus madagascariensis G. Grandidier, 1928, prefers native or introduced fruit of no commercial value (Ficus polita, Syzygium jambos and S. malaccense) to commercially important fruits (Litchi chinensis and Diospyros kaki). We presented 10 fruit species to the bats: one native (F. polita) and the remainder introduced, 3 of which are commercially important. Most bats responded to fruit presented in a flight cage. Bats swallowed fruit juice and pulp and spat out the fibre of all fruit species provided except L. chinensis and Eugenia jambolana, the flesh of which was swallowed. Chemical composition was the most important determinant of selection by bats. Feeding preference was evidenced by large amounts of chewed pulp, repeated visits to the same fruits and more intensive feeding on lipid- and calcium-rich fruit species. Although commercially important fruit such as L. chinensis and D. kaki tended to have higher fructose content than other species, our results indicate that lipid and calcium content were more important in fruit selection. We suggest that maintaining natural food availability in humid forests and providing alternative sources of fruit (e.g. Syzygium spp.) may contribute to limiting the damage caused by R. madagascariensis to commercially important crops.