Temporal patterns of individual and group foraging behaviour in the short-nosed fruit bat, Cynopterus sphinx, in south India

Abstract

The short-nosed fruit bat, Cynopterus sphinx, begins to visit fruit-bearing trees about 30 min after sunset. Individual bats often hover near or land on fruits or on nearby branches to remove whole or parts of fruits with their mouth. These bats seldom remain in the fruit-bearing trees to feed, but instead carry fruits to feeding roosts, repeating this behaviour several times throughout the night. Analysis of the temporal distribution of feeding behaviour has revealed two peaks of activity, one in the pre-midnight hours when bats fed mostly on 'steady state' fruits, and another during the post-midnight hours when bats fed on 'big-bang' fruits. Only solitary bats visited and fed on species with steady state fruiting phenologies, whereas groups of bats regularly visited and fed on species with big-bang fruiting phenologies. Thus, plant species which produce large numbers of fruits appear to promote group foraging during the latter hours of the night. It is suggested that the temporal use of available fruits in south India made it possible for C. sphinx to successfully exploit them, and thereby reduced interference competition with conspecifics.