Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.07.31.229278v1?rss=1 Authors: Naniwadekar, R., Gopal, A., Page, N., Ghuman, S., Ramachandran, V., Joshi, J. Abstract: Mutualistic interactions, like seed dispersal, are important for maintaining plant diversity in tropics. Islands, which have a smaller subset of plants and frugivores, when compared with mainland communities offer an interesting setting to understand the relative role of ecological and evolutionary processes in influencing the interactions between plants and frugivores. In this study, we examined the relative influence of functional traits and phylogenetic relationships on the plant-seed disperser interactions on an island and a mainland site. The island site allowed us to investigate the organization of the plant-seed disperser community in the natural absence of key frugivore groups (bulbuls and barbets) of Asian tropics. The largest frugivore on the island, the point endemic Narcondam Hornbill, was also the most abundant frugivore on the island and played a significant quantitative and central role in the plant-seed disperser community. Species strength of frugivores was positively associated with frugivore abundance. Among plants, figs had the highest species strength and played a central role in the community during the study period. We found that the island had among the highest reported densities of hornbills and figs in the world. Island-mainland comparison revealed that the island plant-seed disperser community was more asymmetric, connected and nested as compared to the mainland community with which it shared certain plant and frugivore species. Neither functional traits nor phylogenetic relationships were able to explain the patterns of interactions between plants and frugivores on the island or the mainland. Diffused nature of interactions between plants and frugivores, trait convergence and plasticity in foraging behavior likely contribute to shaping the interactions between plants and frugivores. This study underscores the need to study plant-seed disperser communities on tropical islands, particularly in the Indian Ocean, which have inadequate representation in the literature. Copy rights belong to original authors. Visit the link for more info