In this study we investigated the importance of two species of fruit bat (Rousettus leschenaulti and Cynopterus sphinx) as seed dispersers for a species of fruit tree (Syzygium oblatum) found in the Xishuangbanna Tropical Botanical Garden in South-West China. We found that although R. leschenaulti and C. sphinx were the two primary seed dispersers of S. oblatum over half of the fruit produced by the tree (65%) fell to the ground. Out of the fruit collected, R. leschenaulti and C. sphinx were able to disperse seeds up to 73 m from the parent tree with the highest density of feeding roosts occurring at 21.3 m (SE = 5.2 m). We found no signs that either species of bat used the parent tree as a feeding roost, instead choosing specific trees that were at lower densities compared with other trees in the forest that were not used. When comparing the viability of seeds in three different habitats (under parent tree, in forest gap, under feeding roost) survival analysis revealed that seedling survival was significantly higher in the forest gap (91.7% ± 4.41%) than under the parent tree (78.3% ± 1.67%), but was not significantly different to seedling survival underneath feeding roosts (86.7 ± 1.67%). Further work also showed that the seeds did not have to be removed from the fruit or ingested by the bat in order to germinate. We conclude that although S. oblatum is not dependent on R. leschenaulti and C. sphinx for successful germination of its seeds, these two species of bat are important seed dispersers and can move seeds to areas where there is a greater chance of germination success and survival.

Frugivorous bats are important seed dispersers for many plant species (Cox et al. 1991, Fleming & Heithaus 1981, Hodgkison et al. 2003a, McConkey & Drake 2006, Nyhagen et al. 2005, Utzurrum 1995). They regularly consume figs in the wild (Fujita & Tuttle 1991, Kalko et al. 1996, Shilton et al. 1999). Various species of pteropodid bats have been reported foraging on the fruits of more than 30 fig species in tropical and subtropical Asia, Africa and Australia (Bhat 1994, Fujita & Tuttle 1991, Marshall & McWilliam 1982, Thomas 1984). Food transit times in frugivorous bats are relatively rapid; generally less than 30 min (Laska 1990, Tedman & Hall 1985). Several studies have demonstrated that seed germination was either enhanced or unaffected after passage through the digestive tract of bats (Figueiredo & Perin 1995, Fleming & Heithaus 1981, Lieberman & Lieberman 1986).