No abstract

Diet and habitat use of the closely related and size-overlapping sympatric Cynopterus brachyotis and C. sphinx were established in lowland dry evergreen forest, Thailand, between March 1998 and March 2000. Feces from netted bats were analyzed, and the recapture rate determined. Although both species share a set of food plants, and fruits from early successional forest contribute about half of their diet, C. brachyotis, the smaller of the two species, ate a significantly greater proportion of fruits from early successional forest than C. sphinx. The latter ate a significantly greater proportion of fruit species in larger size classes. More C. brachyotis were captured in early successional forest in almost every month, while C. sphinx is more common in old-growth forest. However, the capture rate of C. sphinx increased in early successional forest in the mid-dry season when its preferred fruits become available. The recapture rate of C. brachyotis in early successional forest was significantly higher than that of C. sphinx, and the reverse situation was observed in old-growth forest. Male C. sphinx had a significantly higher recapture rate in early successional forest than females. Fruit size and habitat use are the major determinants of resource partitioning between these size-overlapping congeners.