Foraging and Day-Roosting Dynamics of Canopy Fruit Bats in Panama

Radio-tracking was used to monitor day-to-day changes in feeding areas, day-roosting sites, and roost group composition of two species of foliage-roosting fruit bats, Artibeus lituratus and Vampyrodes caraccioli. The bats changed roost sites almost daily but did not move to sites closer to current feeding areas. Relatively stable groups of one male and two or three females with young used and reused several foliage sites in areas of 0.5 to 2.5 ha and commuted to feeding areas up to 2.5 km away. Sit-and-wait predators like owls seem to be attracted to fruiting trees. The bats suspended or greatly reduced feeding passes to fruiting trees during periods of bright moonlight, but searching and commuting flights occurred even in the brightest moonlight. Predation pressure is implicated in the evolution of both foraging and roosting behaviors.