Does habitat specificity by frugivorous birds result in uneven seed rain within Bolivian mixed plantations?

Abstract

Small-scale habitat specificity by frugivorous birds might affect their patterns of use of space and, consequently, may influence the range of habitats over which seeds are disseminated. These differences may translate into non-redundancy among bird assemblages using different habitats. I tested this hypothesis by capturing birds in two habitats within shaded mixed plantations in a Bolivian Andean forest (plantation interior and plantation edges with the forest matrix) and comparing the seeds found in their droppings. I found that, despite differences in bird assemblage composition and activity, the overall seed rain was similar among habitats: the seed rain in edges was only slightly richer in species than in the plantation interior, but species composition did not differ significantly between habitats. Although some seed species showed a biased distribution among habitats that might be partially explained by habitat specificity of frugivorours birds, the overall relative importance of seed species in the seed rain was similar for both habitats. These findings suggest that even when bird assemblages differ among habitats, from the plant community perspective these assemblages might be ecologically redundant.