Vertebrate Assemblage at a Fruiting Fig (Ficus caulocarpa) in Maliau Basin, Malaysia

Abstract

We analyzed the species composition and abundance of birds and mammals at a fruiting hemi-epiphytic fig ( Ficus caulocarpa) in Maliau Basin, Sabah, Malaysia. Observations were conducted for 32 hours over five days. Forty-four species of birds and three mammal species were recorded. Of these, 28 birds and 2 mammals fed on the figs. In addition, nine species of insectivorous or omnivorous birds that did not feed on the figs were observed foraging in the tree, presumably on the large quantities of fig wasps produced. Inter- and intra-specific aggression was also observed among the species foraging in the tree. Overall the assemblage of large birds, such as hornbills, and mammals was poor, which seems to be due to the small size of the figs (<6 mm diameter) rather than a scarcity of these animals in the area. In contrast, the diversity of smaller bird species, especially the Pycnonotidae (Bulbuls) which comprised 13 species and 68% of visits, was high. Our results suggest fig-frugivore interactions may be more finely structured than reports from other, less pristine sites in Asia have indicated. Moreover, 34% of the birds observed are threatened or more severely endangered. We suggest that planting of hemi-epiphytic fig seedlings could be used to enhance the conservation value of small reserves and degraded forests, and that observations at fruiting figs could be used as an efficient method for assessing how well reserves are protected.